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THORACOSCOPY IN ACUTE CARE SURGERY
Thoracoscopy evolved from the diagnosis and treatment of tuberculosis. The earliest report is from Hans C Jacabobaues, who in 1910 used a rigid cystoscope to first perform inspection and then adhesiolysis in the pleural cavity for patients with tuberculosis. Improvements over a century have led to increased use of thoracoscopy for a wide range of therapeutic procedures. These advancements include improvements in anesthesia, endoscopic video systems, types of scopes, instruments, staplers and energy devices. Figure 77.1 shows historical milestones in the development and clinical use of thoracoscopy.
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Indications for Video Assisted Thoracoscopic Surgery
Video assisted thoracoscopic surgery (VATS) offers safe access to all the structures in the chest including the pleura, pleural cavity, lungs, esophagus, diaphragm, pericardium, heart, thymus, anterior and lateral spine, sympathetic chain, thoracic duct, and mediastinal structures and therefore provides surgeons with the ability to perform diagnostic and therapeutic maneuvers inside the chest using a less invasive method and without the need for a thoracotomy.
Although underutilized, there are several indications for the use of VATS in the acute care surgical and trauma arena, as seen in Table 77.1 below .
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VATS is a suitable option for the definitive treatment of stable patients with thoracic trauma. Villavicencio and colleagues demonstrated in a meta-analysis that VATS prevented 62% of thoracic trauma patients from undergoing a thoracotomy or laparotomy, and had a low missed injury rate of 0.8% .
Directly proceeding to VATS prior to the insertion of a thoracostomy tube has been studied and shown to be a safe option in select stable trauma patients [144, 145]. The literature does not definitively say if this action leads to shorter hospitalizations or fewer complications than tube thoracostomy alone.
The Advantages of VATS
The advantages of VATS over thoracotomy include shorter length of stay, fewer pulmonary complications and decreased infectious complications. A study by Ben-Nun and colleagues found that patients with thoracic trauma undergoing VATS required lower doses of narcotic analgesia when compared with those undergoing thoracotomy. They also reported that the average time to resumption of normal activity was shorter in the VATS group, with the rate of return to a normal lifestyle after 2 years being 81% for VATS patients and 60% for thoracotomy patients. The VATS patients not only had less long term disability, but were also generally more satisfied with their health status and surgical scars .
Disadvantages and Complications of VATS
One of the concerns of the VATS approach is that it provides limited exposure due to the bony rib cage and reduced viewing angles on the camera as when correctly placed, the camera has a 180-degree view of the operative field. There is also a reduction in tactile sense which may dampen the ability to differentiate structures and identify lesions.
Conversion of VATS to a thoracotomy is always a possibility and conversion rates of 13.8 % – 31 % have been reported in stable thoracic trauma patients undergoing VATS . The inability to complete the procedure thoracoscopically may be due to difficult access, significant adhesions, or decreased visualization. Emergency conversion may be required if uncontrollable hemorrhage occurs. Therefore the chest should be prepped and draped with this in mind and thoracotomy instruments present in the operating room.
Complications due to VATS are rare and are usually related to the procedure itself. A 2% risk of procedure related complications when utilizing VATS in the acute care / trauma setting has been reported . The most common complications are transient hypoxemia, reversible arrhythmia, wound infection, chest wall bleeding, iatrogenic lung injury and intercostal neuritis as a result of excessive levering on or direct trocar damage to intercostal nerves.
Contraindications to VATS
VATS should never be used in hemodynamically unstable patients and in those patients who have a clear indication for thoracotomy, sternotomy or laparotomy such as patients with associated injuries. Other major contraindications include severe hemorrhage and severe respiratory or cardiac disease precluding single lung ventilation. Absolute and relative contraindications are listed in Table 77.2.
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Technique of VATS
VATS is performed under general anesthesia utilizing a double-lumen endotracheal tube to facilitate full collapse of the ipsilateral lung therefore allowing for adequate inspection of the intra-thoracic cavity and more working space. The patient is placed in the lateral decubitus position with the ipsilateral side up with a bean bag below the patient and hips securely strapped to the table. This makes it easy to convert to open thoracotomy should this be needed. The table is flexed to expand the intercostal spaces, the ipsilateral arm is extended forward and abducted at 90 degrees on an arm board or two pillows and lower leg flexed at knee and upper leg extended with a pillow placed in between the two. All pressure points should be carefully padded and an axillary roll placed under the contralateral axilla to protect the brachial plexus. The chest is prepped and draped and a sterile adhesive plastic drape and standard thoracotomy drapes are placed. Monitors should be placed on either side of the patient at the head of the bed.
Thoracoports are placed carefully and these are used to introduce the camera and instruments. The camera port is typically placed first using a 1 cm incision in the mid axillary line, with a small amount of tunneling over the seventh rib, with care taken to avoid the neurovascular bundle of the inferior rib. The intercostal muscle is divided using cautery and the pleural space is entered under direct visualization. A finger is used to gently sweep away any adhesions to ensure safe insertion of the port. The camera is then inserted and the entire chest inspected. A thoracoport can also be placed in the wound of a removed chest tube. Additional ports, usually one to three, are placed under direct camera visualization and their placement depends on the intrathoracic pathology and patient body habitus and is usually determined after initial thoracic inspection. They are placed at different rib space levels from the thoracoscope in order to allow triangulation of the instruments for good working space. Usually the second port is placed over the 6th rib anteriorly and a third port, if required, placed over the 4th rib anteriorly or posteriorly as required by the situation, see the Figure 77.2 below.
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Once the procedure is complete and hemostasis ensured, including port site inspection, one or two chest tubes are placed through the thoracoport incisions. The chest tubes are placed to continuous suction and monitored, then removed once drainage is less than 100 ml/day and there is no air leak.
VATS in Trauma
Hemothorax is the second most common sequelae of chest trauma (second to rib fractures). Prompt adequate drainage is the treatment of choice for hemothorax and drainage with a large bore 36 to 42 French tube thoracostomy is successful in about 85% of patients .As such, 10-15% of patients will have a retained hemothorax, most commonly due to inadequate drainage from a malpositioned chest tube [150-152]. A retained hemothorax is defined as residual pleural blood occupying more than a third of the thoracic cavity, or residual pleural blood of at least 500 ml, which cannot be drained after 72 hours of tube thoracostomy treatment .
Inadequately drained hemothoraces can either resorb over time, cause fibrosis resulting in fibrothorax or trapped lung, pulmonary atelectasis and difficulty ventilating, or become secondarily infected resulting in an empyema. The risk of complications from retained hemothorax is proportional to the size of the hemothorax. Mortality increases significantly from 0% for adequately drained hemothoraces, to 1.6% if decortication is required and 9.4% if empyema develops [154, 155]. If no intervention is attempted for drainage of the retained hemothorax, up to 40% of patients will end up requiring a thoracotomy .
Retained hemothorax is one of the strongest indications to perform VATS in a trauma patient, as it is seen as marginally more invasive than a thoracostomy tube .Patients in whom a chest tube has been placed for hemothorax require serial screening chest xrays (CXR) to determine resolution of the hemothorax. If the opacification on CXR persists at 48 hours, a CT of the chest should be performed to differentiate between underlying pulmonary contusion versus retained hemothorax because CXR has been found to be a poor predictor of patients requiring a VATS. This was demonstrated in a study by Velmahos and collegues who demonstrated that the etiology of opacification in the setting of traumatic hemothorax on CXR was correctly interpreted in only 47% of cases by radiologists, and 48% by surgeons, after confirmation with CT scan (hemothorax versus lung consolidation). Furthermore, management that would have been instituted based on CXR findings changed in 31% of cases after reviewing the CT chest. Therefore they recommend that CXR be used for screening of retained hemothorax and CT chest for therapeutic decision making .
The Eastern Association for the Surgery of Trauma (EAST) Practice Management Guidelines for the management of traumatic hemothorax. It recommends that all hemothoraces, regardless of size, should be considered for drainage (Level 3) . In multiple retrospective and prospective series, VATS has been shown to be successful 90-100% of the time for the evacuation of retained hemothoraces [142-144, 153, 155, 158].
The prior controversy on a second chest tube versus VATS for retained hemothorax is settled in favor of VATS. The EAST guidelines also recommend that a persistent retained hemothorax, after placement of a thoracostomy tube, should be treated with early VATS and not a second chest tube (Level 1). Figure 77.3 shows a treatment algorithm for the management of traumatic acute hemothoraces.
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The advantage of VATS in this scenario has been proven by Meyer et al who randomized 39 patients with retained hemothoraces to either VATS or a second tube thoracostomy . The patients in the VATS group had shorter length of stay and lower hospital costs than putting in a second chest tube. Also 42% of patients who underwent a second chest tube still ended up requiring a surgical intervention for the hemothorax within that hospitalization. The goals of VATS are 1) drainage of the collection and bacteriologic evaluation of same, 2) decortication and release of trapped lung and 3) lung re-expansion.
The timing of VATS is also an area of research and debate. Lin and colleagues demonstrated that early VATS is associated with a lower rate of empyema, pneumonia and ventilator dependence, and outcomes are worse if VATS was prolonged after 6 days and complications lowest if performed within 3 days . Further, the EAST guidelines recommend that VATS should be done in the first 3 days to 7 days of hospitalization in order to decrease the risk of infection and conversion to thoracotomy (Level 2) .
The rate of operative difficulty becomes higher with delayed VATS, with higher conversion rates to thoracotomy more likely after 5 days [161, 162]. No contraindication exists to attempting VATS outside of this time frame however, and success has been described in cases performed as far out as 14 days from injury .
Fibrinolytics have been proposed as an alternative to VATS for retained hemothorax. Though fibrinolytics have been proven to be safe, when compared to streptokinase, patients who underwent VATS had shorter hospital stay (9.8 ± 3.7 days vs. 14.5 ± 4.2 days) and decreased need for additional procedures. Fibrinolytics should be considered a second line option, especially in patients who are too high risk for surgery .
Pneumothorax is the most common parenchymal injury in thoracic trauma caused by direct injury to the lung in penetrating trauma or rib fractures, or by transmitted forces on the lung such as shearing, rapid deceleration motions or increased alveolar pressure during a valsalva type maneuver during blunt trauma.
Most pneumothoraces heal within 72 hours with appropriate chest tube placement and suction allowing for pleural apposition and the parenchymal disruption to heal. Persistent pneumothorax is defined as continued air leak and failure to achieve full lung re-expansion within 72 hours of chest tube placement and this occurs in about 4 – 23% of patients with thoracic trauma [144, 165]. Patients with persistent pneumothorax should undergo a bronchoscopy to rule out a tracheobronchial injury, which if found would necessitate definitive open repair.
The treatment of persistent pneumothorax has historically been with prolonged chest tube drainage to closed suction, which sometimes may take weeks for resolution. Pleural space fluid, foreign bodies, extensive parenchymal injuries and positive pressure ventilation may prevent healing of the pneumothorax. VATS is widely proven to be successful in patients with spontaneous pneumothorax and its early use in persistent pneumothorax in the setting of trauma has also been shown to decrease the number of chest tube days, shorten length of stay, and decrease narcotic use [144, 154, 165].
The EAST guidelines recommend that a persistent air leak on post injury day 3 should prompt a VATS evaluation (level 2). During the VATS, often the injured segment of lung can be identified and treated with resection using an endo GIA stapler. If the injured segment is not accessible via VATS, then a mini-thoracotomy may need to be performed to repair the injury (see Figure 77.4)[144, 154, 166]. Use of a topical water tight surgical sealant placed via VATS on the area of injured lung (CoSeal; Baxter, Freemont California) has been described by Carrillo and colleagues, and was found to be safe and effective, non reactive and technically easy to apply, even in difficult areas. The patients in their study had decreased length of stay and cost of care with the topical sealant when compared to traditional prolonged chest tube therapy .
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Massive hemothorax or persistent bleeding has traditionally been managed with a thoracotomy, with the criteria for urgent thoracotomy being: more than 1500 ml of blood immediately evacuated by tube thoracostomy, persistent bleeding 150 – 200 ml/hr for 2 to 4 hours, persistent blood transfusion required for hemodynamic stability. These were based on descriptive retrospective studies. However the EAST guidelines now recommend that patient physiology, rather than absolute numbers, should be the primary indication for surgical intervention (Level 2) and that 1500 ml via chest tube in any 24-hour period, regardless of mechanism should prompt consideration for surgical exploration (Level 2).
Hemodynamically stable patients who experience slow-rate ongoing bleeding (100 – 150 ml/hr) in the thoracic cavity can be managed safely with VATS. The etiology is usually from a bleeding intercostal vessel or parenchymal lung injury, although once the lung is re-inflated it usually tamponades its low pressure vascular system which stops most parenchymal bleeding.
Methods of thoracoscopic control of ongoing bleeding include clip ligation, diathermy, argon beam and endostaplers with a reported success rate of 82% . If unable to control the bleeding using these maneuvers, the bleeding vessel can be temporarily compressed thoracoscopically while the skin incision is opened externally and the bleeding vessel ligated through the open wound without a thoracotomy.
Care must be taken as controlled bleeding can be disrupted to cause more severe hemorrhage, and with the inability to control significant bleeding, conversion to thoracotomy must be performed. This is likely to be required more frequently in cases where the bleeding is more central and closer to the mediastinum. Conversion rate to thoracotomy in patients with ongoing bleeding is 15 – 20 % . If one is able to achieve hemostasis with VATS patients have fewer chest tube days, transfusions and earlier discharge [153, 155].
Diaphragmatic injury occurs with blunt trauma in 2 – 5% of patients and in 19 – 24% of penetrating thoraco-abdominal trauma cases [168, 169]. It is missed in 10 – 30% of cases with standard diagnostic tests (CXR, CT scan, ultrasound)  and the best method of diagnosis is direct visualization. When missed it can lead to chronic diaphragmatic hernia, incarceration of abdominal organs, strangulation and the mortality associated with this injury has been reported as high as 36% .
The EAST guidelines recommend that primary VATS of stable penetrating thoracoabdominal wounds is safe and effective for the diagnosis and management of selected diaphragm and pulmonary injuries (Level 2).
In patients with suspected diaphragmatic injuries, there has been debate regarding which procedure, VATS or laparoscopy, is better for diagnosis. VATS allows thorough examination of the diaphragm, mediastinum and hemithorax with a more complete view of the diaphragm, particularly of the right posterior diaphragm, which is difficult to visualize from the abdominal approach. The best visualization is achieved when the scope is inserted in the 4th or 5th intercostal space. It is particularly useful in patients who have no indication for a laparotomy or thoracotomy. It does not require insufflation, and therefore is not associated with the hemodynamic consequences of decreased preload, which happens in laparoscopy. Also, creation of a tension pneumothorax through the diaphragmatic injury during laparoscopic insufflation has been reported in the literature in a few cases .
Ivatury et al have proposed that VATS be used for posterior wounds between the posterior axillary line and spine . VATS for anterior wounds associated with a pneumothorax give the advantage of evaluating the injured lung and evacuating hemothorax and evaluation of bleeding. For anterior wounds without pneumothorax, particularly those which are low and tangential, laparoscopy is preferred to evaluate for abdominal injuries .
Accuracy in VATS for diagnosis of diaphragmatic injury is 94 – 100%, and missed injury rate has been reported as 4% [143, 154]. It has a sensitivity of 98 – 100% and therefore is a good diagnostic tool.
Disadvantages of this approach are cited as time consuming for patient positioning, patient has to be able to tolerate single lung ventilation and it is mandatory for a chest tube to be inserted afterward regardless of findings. Also, if a diaphragmatic injury is seen via VATS, repair is technically difficult and may require conversion to open repair. Diaphragmatic injuries are associated with a high rate of intra-abdominal injuries and abdominal inspection is required if diagnosed.
Delayed repair of diaphragmatic injuries is typically performed via a thoracotomy incision due to extensive adhesions within the thoracic cavity.
Post Traumatic Empyema
Empyema is an infection of the pleural space characterized by purulent fluid within the space. It is caused most frequently by lung parenchymal infections, thoracic procedures and thoracic trauma. The diagnosis is usually confirmed by imaging and positive bacterial cultures of the fluid. The rate of empyema development after trauma ranges from 2 – 27 % in most series, with the post-traumatic empyema rate after adequately drained hemothoraces being 1.6%  and with retained hemothoraces documented as 26.8% in an observational study by DuBose and the American Association for the Surgery of Trauma .
Success of treatment relies on adequate drainage of the collection and re-expansion of the lungs to prevent fibrosis and functional limitations. This depends on the phase of the empyema with the best opportunity for success afforded in the acute / exudative phase (1 – 5 days) rather than later in the fibrinopurulent / transitional phase (5 – 14 days) or organized / chronic phase (> 14 days) where thick peels, loculations and adhesions prolong operative time, increase complications and have higher rates of conversion to thoracotomy.
VATS drainage and decortication in post-traumatic empyemas (all phases) have been shown to be associated with 54 – 86 % success rate. It was uniformly successful in all acute / exudative phases, and 75 – 85% successful in the fibrinopurulent / transitional phase. VATS drainage has been shown to be the better approach for earlier empyemas under 10 days before the development of significant fibrous reaction .
Thoracic Duct Injury
Thoracic duct injury is rare, it presents as chylothorax and following trauma it is more common in blunt than penetrating trauma usually as a result of shearing forces. The collected fluid is typically milky white in appearance and high in triglycerides and lymphocytes. It is usually treated with chest tube drainage and low fat diet. However if drainage persists beyond 14 days surgical intervention is required.
VATS, rather than the traditional right-sided thoracotomy, can be used to drain the chyle and ligate or repair the injured thoracic duct. Although the data on thoracoscopic repair of post-traumatic thoracic duct injuries is sparse, success rates of 80 – 90 % have been reported .
Foreign Body Removal
VATS to remove foreign bodies from the thoracic cavity has been reported in numerous case reports in the literature which describe its safety and efficacy . Symptomatic impacted foreign bodies delay healing of alveolar-pleural fistulae and prevent lung re-expansion. Asymptomatic foreign bodies do not require removal.
Diagnosis of cardiac and mediastinal injuries
The use of VATS in the diagnosis of hemopericardium by a thoracoscopic pericardial window has been reported. Morales et al used it to rule out cardiac injury in stable patients with penetrating wounds near the heart and no obvious signs of cardiac injury. Thirty percent of patients had occult hemopericardium. The procedure was reported to be 100% sensitive and 96% specific with an accuracy of 97%, and no deaths . However there is limited data on pericardioscopy and given the advances in imaging technology, cardiac and mediastinal structures are evaluated mainly with noninvasive means such as cardiac ultrasound or CT angiogram chest which may prompt a subxiphoid pericardial window or open exploration of mediastinal hematomas [176, 177].
LAPAROSCOPY AND THORACOSCOPY IN PEDIATRIC ACUTE CARE SURGERY
In 1971, Gans and Berci described laparoscopy in 16 children. Using the term peritoneoscopy, they reported the confirmation of an inguinal hernia by placing an endoscope into the contralateral hernia sac. As minimally invasive surgery (MIS) increased in popularity in the adult population in the 1990s, there was slow adoption among pediatric surgeons partially because of the limited availability of smaller instrumentation and also because of the physiological differences of infants and children from adults. The first reported cases were laparoscopic cholecystectomies and appendectomies. With the introduction of newer, more precise instruments with finer tips, better insulation, and better optics, came a broader application of minimally invasive techniques to pediatric surgery. Today, a number of procedures are performed laparoscopically and thoracoscopically in infants and children. (Table 77.3)
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Despite this list of applications, minimally invasive techniques are still not universally performed for the majority of pediatric surgical procedures. Although most pediatric surgeons perform laparoscopic appendectomy, only a third perform laparoscopic pyloromyotomy and even less attempt more complex procedures using a minimally invasive approach. Published evidence that laparoscopy and thoracoscopy are safe, feasible and, in some cases superior to open surgery has emerged within the last decade. However, studies providing level 1 evidence are limited to a few of the more common procedures namely appendectomy, inguinal hernia repair, pyloromyotomy, orchidopexy, varicocelectomy, fundoplication, and pyeloplasty. More randomized controlled trials are needed to inform guidelines and recommendations for MIS applications in pediatric surgery.
Acute care surgery has not been defined as a distinct subspecialty of pediatric surgery. However, as in adults, in addition to trauma, there are several conditions that warrant emergent or urgent surgical attention in the pediatric patient. The role of MIS in the most common of these conditions forms the body of this section, as well as brief discussions of the advantages of MIS in this population and the hindrances to more widespread use.
Benefits of minimally invasive techniques in pediatric surgery
Similar to the experience in adult patients, minimally invasive surgery provides several advantages when compared to open procedures, some of which provide unique benefits to the pediatric population. The smaller incisions afforded by laparoscopy and thoracoscopy are thought to confer reduced closing tension on the skin, which in turn results in less wound dehiscence, incisional hernias, less postoperative pain, and less superficial surgical site infections than the open approach. Further, thoracotomy incisions are associated with significant postoperative pain and the need for epidural infusion and narcotic analgesia, as well as the risk of long-term chest wall deformity and scoliosis. Thoracoscopy, in contrast, has been shown to result in less musculoskeletal morbidity. In a comparative study of thoracoscopy versus thoracotomy, Lawal et al demonstrated reduced incidence of scoliosis, better cosmesis and less alterations of nipple-sternum distance as well as chest diameter in those who underwent thoracoscopy. As in adults, minimally invasive surgery results in less postoperative adhesion formation, and although the exact mechanism is unknown, it is thought to be associated with decreased tissue handling and reduced exposure to the materials in surgical gloves.
Neonatal minimally invasive surgery
Laparoscopic and thoracoscopic approaches have been described for a number of neonatal surgical diseases and the safety and feasibility of many of these procedures have been described in the literature.
The unique physiology of the neonate, however, warrants special consideration as it relates to minimally invasive surgery. For example, neonates have higher sensitivity to CO2 insufflation with increased absorption and sensitivity of the cardiovascular system to its effects. Pressure maximums of 8-10 mm Hg with very slow pressure increases are needed to avoid a decrease in circulatory volume and metabolic acidosis. Intraoperative hydration is imperative given the decrease in preload associated with increased intra-abdominal pressure, and for these patients colloids are actually preferred. Persistence of the fetal circulation, with patent umbilical vessels and right-to-left shunts, places the neonate at higher risk for inadvertent gas embolism during laparoscopy. CO2 insufflation reduces lung compliance and functional residual capacity and also increases oxygen consumption and pulmonary resistance. Hyperventilation is required to counteract these effects. Finally, the majority of neonates develop temporary anuria during laparoscopic procedures due to the renal perfusion effects of the increased abdominal pressures. Careful attention to fluid balance is thus required in these patients. (Table 77.4)
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The most common causes of the acute neonatal abdomen are necrotizing enterocolitis (NEC), midgut volvulus, intestinal atresia, meconium ileus, and Hirschsprung’s disease. Diagnostic laparoscopy in these patients can potentially avoid the morbidity of a laparotomy or facilitate the placement of smaller incisions depending on the surgical pathology identified. In a review by Burgmeier and Schier of 17 neonates who underwent diagnostic laparoscopy at a median age of 4 days, 53% (9 patients) avoided a laparotomy, and 41% (7 patients) had successful laparoscopic treatment of midgut atresia, volvulus, and appendectomy. Thoracoscopy in neonates is more commonly used for the management of congenital diaphragmatic hernias and tracheoesophageal fistulas, discussed later in this section.
Surgical NEC is one of the more common indications for emergent abdominal exploration in the neonate and deserves special mention. Laparoscopy is thought to offer benefit, particularly when signs of bowel perforation are absent. Although the only absolute indication for surgery in NEC is intra-abdominal perforation, there are several relative indications based on clinical, laboratory, and radiological parameters. For these latter indications, it appears that laparoscopy may play a role, although this is currently limited. In a recent international survey of pediatric surgeons, only 8% performed laparoscopy for diagnosis or treatment of NEC. However, laparoscopy can facilitate the visualization of bowel to determine its viability and also allow for the identification of patients who may not need therapeutic intervention, thus avoiding the physiological stress of a laparotomy in this already vulnerable subpopulation. In the event that necrotic bowel or perforation is encountered, the procedure is converted to open. In other cases, drain placement can be performed laparoscopically for cloudy peritoneal fluid. In a recent systematic review of the evidence for the use of laparoscopy in NEC, Smith and Thyoka identified 6 case series and 1 case report on the use of laparoscopy in 44 infants. The techniques described included standard laparoscopy in 28 cases, fluorescein-aided assessment in 8 cases, and gasless laparoscopy in the other 8 cases. Most patients required additional procedures but further surgery was avoided in 18%. In a Malaysian case series, diagnostic laparoscopy was performed using a 3.5mm trocar and a 1.9 mm telescope in 4 low-birth weight infants with focal intestinal perforation. Laparoscopy allowed localization of the perforation and exteriorization of the bowel for resection. Surgical NEC, despite the lack of high-quality evidence, is thus another potential application of MIS in the neonatal population.
Minimally invasive surgery in pediatric trauma
Trauma is the leading cause of death and disability in children and abdominal injuries affect 10-15% of injured children, second only to head injuries in frequency. Blunt trauma is significantly more common than penetrating, and the spleen is the most frequently injured organ. The anatomic differences of the child compared to the adult account for the variability in injury patterns. Children are smaller in size, with more compact organs and have less subcutaneous fat and muscle to absorb the energy from impact. The bony skeleton with its incomplete ossification offers less protection to underlying organs and the pelvis is typically immature. Physiologic differences also affect evaluation in that vital signs are age-specific, and the average child can lose up to 45% of circulating blood volume before demonstrating hypotension.
The major role of MIS in pediatric trauma therefore lies in the diagnostic and potential therapeutic capability of laparoscopy and thoracoscopy in the patients with penetrating abdominal injury, suspected diaphragmatic injury, thoracoabdominal trauma, suspected hollow viscus injury, or a worsening clinical examination. (Table 77.5)
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Carnevale et al, in a report on the use of “peritoneoscopy” in trauma, included 5 patients under 18 years of age who were spared a laparotomy. The use of laparoscopy in 8 pediatric trauma patients was reported by Chen et al dating back to 1995. Since then, MIS in pediatric trauma has seen slow but increasing adoption. The most common mechanisms of injury in one review of 200 patients evaluated with MIS included motor vehicle collisions, stab wounds, bicycle crashes, gunshot wounds and falls. The morbidity of a negative laparotomy exceeds 20% and includes wound infections, pneumonia, ileus, the potential for adhesive disease and bowel obstruction, and abdominal wall hernias.[193, 194] There is also a significant mortality of approximately 5-6%. MIS reduces the negative laparotomy rate in many studies, and provides the advantages of smaller incisions, reduced postoperative pain, quicker return of bowel function, faster recovery, decreased hospital length of stay, reduced hospital costs, and development of fewer adhesions in the long term.[189, 193] This reduction in negative exploration must be weighed against the rate of missed injuries and delay in diagnosis when comparing MIS to the traditional laparotomy. In one review, laparoscopy was shown to decrease the rate of non-therapeutic laparotomy from 54-65% to 11-50% in both blunt and penetrating trauma. In a 5-year retrospective review of a pediatric level 1 trauma database, 32 of 113 patients had initial diagnostic laparoscopy performed and laparotomy was avoided in 56% of these cases. In a 12-year review of 21 patients who underwent diagnostic laparoscopy, the need for open surgical exploration was decreased by 62%. In terms of missed injuries and diagnostic delay, the Focused Abdominal Sonography in Trauma (FAST) exam has lower utility in children because of its lower sensitivity and specificity (numbers) in this population, In addition, the presence of free fluid alone does not mandate operative intervention. Further, CT scans are associated with lower sensitivity for intestinal, mesenteric, and diaphragmatic injuries, as well as the associated risks of radiation exposure. Diagnostic laparoscopy therefore offers a highly sensitive and accurate tool for screening for these injuries while avoiding the morbidity of a laparotomy. Indeed the accuracy of MIS in trauma approaches 100% with many studies reporting no missed injuries.[189, 195] Of 21 diagnostic laparoscopies over 20 years at a pediatric trauma center, Stringel et al report only 1 missed injury which was a duodenal perforation identified on postoperative imaging due to high suspicion.
It cannot be overstated that the absolute contraindication to MIS in pediatric trauma remains hemodynamic instability. Relative contraindications include inability to tolerate insufflation, coagulopathy, increased intracranial pressure, congestive heart failure, evisceration, multiple organ injury, and generalized peritonitis.
The therapeutic role of laparoscopy in pediatric trauma continues to expand and several procedures are now successfully completed without conversion including bowel resection, repair of enterotomies, distal pancreatectomy, splenectomy, and repair of traumatic hernias. Conversion rates to open vary depending on injury, attempted procedure, and surgeon expertise. In one review, a conversion rate of 37% was reported for 192 children undergoing laparoscopy for abdominal trauma. In another review of 23 children undergoing MIS for trauma over 20 years at a level 1 pediatric trauma center, 63% underwent conversion to an open procedure after positive findings were encountered on diagnostic laparoscopy.
Solid organ injury rates from blunt trauma are higher in children than adults. Management of these injuries is largely nonoperative and indeed many pediatric trauma centers now follow the Arizona-Texas-Oklahoma-Memphis-Arkansas Consortium
(ATOMAC) protocol for blunt liver or spleen injury. Developed by a group of level 1 pediatric trauma centers, the ATOMAC protocol updates the previous American Pediatric Surgical Association guidelines. The earlier APSA guidelines recommended nonoperative management based on grade of injury. In contrast, the ATOMAC protocol recommends: (1) nonoperative management based on hemodynamic status, (2) a shortened period of bed rest for stable children with unchanged hemoglobin levels, (3) a transfusion threshold of 7.0 g/dL, and (4) surgical intervention or urgent embolization for hemodynamic instability, inadequate response to transfusion, or ongoing bleeding. Stable patients with solid organ injury who require intervention can therefore benefit from a minimally invasive approach. In these cases, bleeding from the spleen, for example, can be controlled with cautery, collagen products, or a splenorrhaphy bag.
Given the adoption of MIS approaches in the pediatric trauma evaluation, several management algorithms have been developed to aid in patient selection for laparoscopy, and in some cases, thoracoscopy. Although there is no standardized approach, commonalities include initial CT evaluation of the hemodynamically stable child with blunt abdominal trauma and either a concerning abdominal examination, elevated liver function tests, or a positive FAST. Those with solid organ injury on CT are typically managed nonoperatively while those with evidence of hollow viscus or suspicion of diaphragmatic injury undergo laparoscopy. The child with a “seat belt” sign with free fluid on CT and no evidence of solid organ injury is thus a classic candidate for diagnostic laparoscopy. Similarly hemodynamically stable children with such penetrating trauma mechanisms as anterior abdominal stab wounds or tangential gunshot wounds can also be evaluated with laparoscopy. (Figures 77.5, 77.6)
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Laparoscopy in trauma typically begins with peritoneal access via the umbilicus using either a Veress needle or Hassan technique. CO2 insufflation is then introduced to pressures of 9-12 mm Hg and flows of 0.5-2 mL/min. Initial 4- or 5-mm port placement is usually at the umbilicus with additional ports placed according to injury suspicion. The abdomen is then inspected sequentially for injury. Primary repair of small gastric, small bowel and colon injuries encompassing less than 50% of the bowel wall circumference can usually be completed intracorporeally, while more complex resections can be performed via a mini-laparotomy incision, typically extended from the nearest trocar incision, through which resection and either a hand-sewn or stapled anastomosis can be performed. In a 5-year retrospective review of 50 children who had sustained isolated intestinal trauma, Streck et al reported that laparoscopic exploration was performed in 14 patients in which 6 had complete intracorporeal repair of simple gastrointestinal perforations and an additional 6 had lap-assisted resection for more complex injuries. There were no reported complications in the laparoscopy group. Injuries to the colon can be managed in a similar fashion. Depending on the injuries identified on the abdominal exploration, other procedures can be performed laparoscopically, lap-assisted, or with conversion to open, depending on case complexity and/or surgeon expertise.
Thoracoscopy in trauma has been less avidly adopted in the pediatric population but some studies have reported on successful diagnostic and therapeutic interventions including decortication and evacuation of hemothorax, lung laceration repair or pulmonary wedge resection, repair of diaphragmatic injury, and removal of foreign bodies. In one of the earliest reports on its use, thoracoscopy was used in 2 children with penetrating trauma and potential mediastinal injury. In a multicenter study of 6 pediatric trauma centers in the United States, Alemayehu et al report on 8 patients who underwent thoracoscopy and 5 patients who had both laparoscopy and thoracoscopy. In these 13 patients, the indications for thoracoscopy were penetrating injury, failed chest tube management, and large hemothorax. Only 1 patient had conversion to thoracotomy and 8 had successful therapeutic interventions. Thoracoscopy is performed with the use of 5- or 10-mm trocar in the 6th or 7th intercostal space in the midaxillary line, a site which can be subsequently used for thoracostomy tube placement. Contraindications to thoracoscopy, aside from hemodynamic instability and/or life-threatening injury, include inability to tolerate single-lung ventilation and obliteration of the pleural space.
In conclusion, MIS has great potential for more widespread application in the evaluation of pediatric trauma patients and, although it is increasing in popularity in recent years, it is still significantly underutilized and understudied. Marwan et al, in a 12-year review of 4,836 pediatric trauma admissions showed that only 21 of 92 abdominal explorations were performed laparoscopically despite high diagnostic and therapeutic success rates. Thoracoscopy is only rarely mentioned in the published literature on pediatric trauma. It is likely that as the evidence continues to demonstrate the safety and accuracy of MIS in this field, there will be more universal adoption. Sim centers, training, expertise
Appendicitis is the most common surgical emergency in children and is perhaps the condition where laparoscopy has been most universally adopted. It is estimated that approximately 70,000 appendectomies are performed in the US on children every year in the US, at an average cost of $9000. Appendicitis is traditionally classified as either acute and uncomplicated, or perforated. The latter occurs in about 30% of cases, and management options include immediate/early appendectomy, or percutaneous drainage and intravenous antibiotics, followed by an optional interval appendectomy. In a review of the Pediatric Health Information System, an administrative database of tertiary level children’s hospitals, Gasior et al found that the proportion of laparoscopic appendectomies increased from 22% in 1999 to 91% in 2010.
When compared with the open approach, several studies have demonstrated decreased wound infection, decreased postoperative length of stay, decreased postoperative ileus and earlier return to activity.
Congenital hypertrophic pyloric stenosis is the most common surgical condition of infants, affecting predominantly males, with an incidence of 2.4 per 1000 live births. The pyloric muscle is abnormally thickened resulting in gastric outlet obstruction that typically presents as projectile nonbilious emesis in infants 2 weeks to 2 months of age. The curative procedure is a pyloromyotomy, first described by Ramstedt in 1912, in which the pyloric muscle is incised longitudinally to release the restriction. The traditional open approach is via either a supraumbilical or right upper quadrant incision.
Alain first reported the laparoscopic approach in 1991 and either a 3-port technique or SILS can be used.[182, 206] The most common technique uses a 5-mm periumbilical camera port followed by two lateral stab incisions through which 2.7mm instruments are introduced for manipulation. The most common complication following pyloromyotomy is postoperative emesis, which can delay return to full feeding. However, the more significant complications are duodenal injury, mucosal perforation, and incomplete pyloromyotomy.
When compared to open surgery, laparoscopic pyloromyotomy has been associated with decreased length of stay, shorter time to full feeds, and with no significant differences in mucosal perforations, wound infections, or incisional hernias.[203, 208, 209] Laparoscopic pyloromyotomy has also been associated with decreased operative time and improved cosmesis over the open approach.[210, 211] Further, in a study of cost-effectiveness of laparoscopic versus open pyloromyotomy, laparoscopic patients were found to be $1,263 less expensive to treat than their open surgery counterparts. There has been some concern that laparoscopy is associated with an increased incidence of incomplete pyloromyotomy,[211, 212] including a recent retrospective review at a children’s hospital in Liverpool which showed an increased risk of repeat pyloromyotomy when laparoscopy was used. St Peter et al conducted a prospective randomized trial of open versus laparoscopic pyloromyotomy in 200 patients and found no cases of incomplete myotomy in the laparoscopic group. In one of the largest series to date, Hall et al reported on 2830 patients at nine high-volume institutions and found that the laparoscopic approach was indeed associated with a slightly increased incidence of incomplete myotomy (0.29% vs. 1.16%), albeit of unclear clinical significance. In a small series of 33 patients reported by Linnaus et al, one method of assessing the adequacy of pyloromyotomy is described in which the top of the serosa on one side of the pylorus is confirmed to reach the bottom of the muscle on the other side. (Figure 77.7) In this series, there were no cases of incomplete pyloromyotomy.
<fig7> – Figure Call-out
<dfig7> – Figure Legend
There is a learning curve associated with laparoscopic pyloromyotomy, which is thought to plateau only after 20 to 30 cases[217-219] and it is likely that this contributes to the slower adoption of this procedure among pediatric surgeons.
Laparoscopic Ladd’s procedure
Intestinal malrotation refers to a congenital malpositioning of the midgut in which the duodenojejunal flexure is found to the right of the midline with an associated narrow mesentery. This abnormality of rotation places the patient at risk of volvulus and massive intestinal loss. The traditional procedure, originally described by William Ladd in 1936, comprises anticlockwise derotation of any volvulus present, followed by division of peritoneal (Ladd’s) bands, widening of the root of the mesentery, placement of the small bowel in the right quadrants of the abdomen and the large bowel on the left, and finally, appendectomy. Van der Zee and Bax first reported the laparoscopic Ladd’s procedure in 1995.
It is currently recommended that symptomatic patients undergo surgical intervention. In recent years, there has been an increase in patients with an incidental finding of abnormal rotation on imaging. For these asymptomatic patients it has been suggested that surgery may be more beneficial for younger patients, particularly those less than 19 years, and observation for older patients. However, the decision is still highly individualized. The laparoscopic approach is thought to confer an advantage, particularly for the latter asymptomatic group of patients. Laparoscopy allows the distinguishing of true malrotation from nonrotation and atypical rotation abnormalities, especially when upper gastrointestinal studies are equivocal.[221, 222] The American Pediatric Surgical Association outcomes and evidence-based practice committee reported level 3-4 evidence and a grade C recommendation for operation on younger asymptomatic patients, and for the laparoscopic approach in children. There was minimal evidence for support of this procedure in neonates. For the symptomatic patient, athough the open approach is still currently the common practice, several studies have reported the safety of laparoscopy as an alternative. Compared to open surgery, the laparoscopic Ladd’s operation is associated with smaller incisions, decreased hospital length of stay, decreased time to return to full feeds, as well as decreased wound infections, readmissions, and postoperative bowel obstruction.[220, 223] A recent review of the National Surgical Quality Improvement Program Pediatric (NSQIP-P) database also showed shorter length of stay in the laparoscopic group but did not show a significant difference in 30-day complications between the two groups. Of note, the decreased adhesion formation associated with laparoscopy seems to lead to an increased incidence of postoperative volvulus in these patients. In a recent survey of the Canadian Association of Pediatric Surgeons, almost half of respondents believed that the laparoscopic approach led to increased postoperative volvulus while the other half did not. Some cited inadequate widening of the mesentery as another etiology of this complication. Conversion rates to open are also not insignificant, ranging from 22-33% in one review.
In current practice the choice of open versus laparoscopic Ladd’s seems to be both surgeon and institution dependent. The aforementioned survey reported that the majority of Canadian pediatric surgeons had performed and felt adequately trained to perform the laparoscopic Ladd’s procedure. Fifty five percent had performed either technique as their standard approach However, there have been studies that caution against the use of laparoscopy in confirmed cases of acute volvulus. (ref) In one such small series by Kalfa et al, it is proposed that patients undergoing laparoscopic repair of subacute volvulus have good hemodynamic parameters, no evidence of intestinal perforation, and no severe bowel ischemia on preoperative imaging. Thus, an individualized approach for this subset of patients is likely to continue until more prospective trials can define more clearly the appropriate selection criteria.
Incarcerated inguinal hernias
Inguinal hernia repair is one the most common pediatric surgical procedures. Approximately 0.8-4% of all term infants and children have an inguinal hernia and the incidence increases to as high as 30% in premature infants. When untreated, the risk of incarceration is approximately 6-18%, and is also increased in the premature population. With incarceration there is an increased risk of postoperative complications that are otherwise uncommon, such as testicular atrophy, bowel ischemia and wound infections.
The initial management of incarcerated inguinal hernias is usually an attempt at nonoperative reduction unless there are signs of bowel compromise, peritonitis, or hemodynamic instability, as 70-95% of incarcerated hernias can be successfully reduced. Operative reduction is performed emergently if the hernia cannot be reduced or if reduction is incomplete. In the event of a successful reduction, it is recommended that hernia repair be performed during the same admission after allowing the edema to resolve, although some providers allow the patient home with very close follow-up for repair.
During open repair of incarcerated inguinal hernias, the tissues encountered may be quite edematous and friable. There may also be nonviable strangulated bowel mandating resection, which can sometimes be accomplished via the right lower quadrant incision but may require a midline laparotomy. The laparoscopic approach to incarcerated inguinal hernias is considered safe and feasible and can be performed with either intraperitoneal or extraperitoneal techniques. When compared to open, laparoscopy has been shown to have similar outcomes. In a retrospective review of 72 children with incarcerated inguinal hernias of which 45 underwent open herniotomy and 27 had laparoscopic repair, Mishra and colleagues found no differences in recurrence, wound infection, or testicular atrophy between the two groups. However, laparoscopy is thought to offer several advantages in the repair of incarcerated inguinal hernias. The pneumoperitoneum is thought to widen the internal ring allowing easier reduction of bowel contents. The bowel can be directly visualized to confirm viability and complete reduction. The contralateral groin can also be examined, and repaired if necessary, without additional incisions. Less common hernias, such as direct or femoral, can be identified. Laparoscopic repair is also felt to be technically easier to perform because there is less dissection of edematous tissue. Furthermore, as in other procedures, laparoscopic inguinal hernia repair is associated with shorter hospital stay, decreased postoperative pain, more rapid return to normal function, and improved cosmesis.
Congenital diaphragmatic hernia repair
Congenital diaphragmatic hernia (CDH) is a life-threatening surgical condition usually requiring repair in the neonatal period. Most patients present within the first 24 hours of life and defects are more common on the left side. Silen et al and Van der Zee et al reported the first use of minimally invasive surgery for the Bochdalek type of congenital diaphragmatic hernia repair in 1995.[230-232] Both thoracoscopic and laparoscopic approaches have been used, although thoracoscopy is considered advantageous as it offers better visualization of the defect after reduction of the herniated viscera.
Given the physiologic stress with which these neonates often present secondary to underlying lung hypoplasia and reactive pulmonary hypertension, the importance of appropriate patient selection for a minimally invasive approach cannot be overstated. However, these selection criteria have not been clearly defined and are currently institution dependent. In a one-year prospective study of 30 neonates with CDH, Yang et al used anatomic and physiologic selection criteria for thoracoscopic repair and had no perioperative complications. These criteria included stomach in the abdomen on radiography, minimal ventilator support with peak inspiratory pressures in the low 20s mm Hg, and no evidence of pulmonary hypertension. In a review of 15 studies, mostly retrospective, Vijfhuize et al found that those who underwent open repair were more likely to be on extracorporeal membrane oxygenation (ECMO) and undergo patch repair. Similarly, a query of the CDH Study Group from 2007 to 2015 revealed that those who underwent open repair were more likely to have lower APGAR scores, be premature, or have major cardiac anomalies, suggesting that these should be considered in patient selection. Stable hemodynamics, the absence of cardiac anomalies, no need for high-frequency oscillatory ventilation, and no herniated liver are other criteria for thoracoscopy cited in the literature.
When compared to open surgery, MIS repair of CDH has been associated with shorter postoperative ventilation, lower postoperative ventilator settings, decreased use of narcotics, faster return to feeds, shorter hospital length of stay, fewer episodes of postoperative small bowel obstruction, lower hospital charges, and improved cosmesis. However there have been reports of an increased recurrence rate.[230, 235, 236] In a review of the CDH registry from 1995 to 2010, there was increased recurrence in the MIS group (7.9% v. 2.7%). This higher recurrence rate is thought to be at least partially due to the learning curve for the procedure. Technical factors such as spacing of the sutures, excessive tension causing tearing of the diaphragm, and inadequate mobilization of the peripheral rim of diaphragmatic tissue have also been considered to contribute to recurrence. In addition, recurrences have also been attributed to poor patient selection for the MIS approach.
There have been concerns about the morbidity of intraoperative hypercapnia and acidosis related to thoracoscopic CDH repair. In a randomized controlled trial of open versus thoracoscopic repair by Bishay et al, the mean intraoperative PaCO2 was significantly higher and the mean pH significantly lower in the thoracoscopy group. It was thought that high initial insufflation pressures would result in higher CO2 absorption, which would partially explain these findings, but the risk of neurotoxicity certainly requires that this effect on blood gases be thoroughly investigated.
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