Management of Postsurgical Leaks in the Bariatric Patient




Postsurgical leaks after bariatric procedures are a significant cause of morbidity and mortality. They usually arise from anastomotic and staple line failures that are attributed to surgical technique, ischemia, and patient comorbid conditions. Timely diagnosis from subtle clinical clues is the key to appropriate management. Traditional treatment consists of adequate control of the intra-abdominal infection via surgical or percutaneous drainage maneuvers, antibiotics, and nutrition support via parenteral or feeding tube routes. Recently, endoscopically placed covered esophageal stents have been used to exclude the leak site, allowing oral nutrition and speeding healing.


Surgery is the most effective modality to treat morbid obesity, as reported by Pories and colleagues, who rigorously followed more than 600 patients over a period of 16 years, demonstrating that gastric bypass produced durable weight loss greater than 100 lb and successful control of comorbidities. The application of laparoscopic techniques first described by Wittgrove and Clark has led to a dramatic increase in the demand and use of surgery to treat morbid obesity. The number of annual bariatric procedures has steadily increased, reaching more than 100,000 in 2003. This increase in the use of bariatric surgery carries with it an expected increase in the absolute number of surgical complications. Among the most devastating complications is that of a postsurgical leak. Diagnosis of these leaks can be difficult because of the lack of clinic signs and symptoms in this population. Morbidly obese patients also have comorbid conditions that further contribute to postoperative morbidity.


Pulmonary embolism is responsible for the majority of postoperative bariatric deaths. If not fatal, pulmonary emboli are treated with anticoagulation and do not greatly increase hospital morbidity. In contrast, bariatric leaks often result in a systemic illness that prolongs hospital stay and may lead to multisystem organ failure that can be fatal. Postsurgical leaks produce a 2-fold increase in mortality and a 6-times increase in hospital stay compared with patients without leaks.


The development of covered esophageal stents has provided a new tool in the treatment of postsurgical leaks. These removable stents can decrease hospital stay and simplify management of this patient group. The aim of this article is to discuss the current diagnosis and treatment of postsurgical leaks in bariatric patients.


Causes


Postsurgical leaks in bariatric patients generally occur at locations where a transection or anastomosis is made. These include the gastrojejunal anastomosis, the gastric pouch staple line, the gastric remnant staple line, the jejunojejunostomy, and, in the case of the duodenal switch, the duodeno-ileal staple line. The cause of bariatric leaks is unclear but likely secondary to technical factors, including anastomotic tension, tissue ischemia, and staple line sizing as well as anatomic variations of tissue thickness and blood supply. Various techniques have been described to limit tension on the gastrojejunal anastomosis. Scott and de la Torre described positioning the Roux limb in the vertically divided omentum as a method with which to alleviate tension on the Roux limb at the gastrojejunal anastomosis. Higa and colleagues describe retrocolic techniques that minimize the distance the Roux limb must extend in attaching to the gastric pouch. Fernandez and colleagues reported that older age, male gender, and sleep apnea were all statistically significant independent variables in groups experiencing a postsurgical leak versus those that did not.




Incidence


Leaks after bariatric surgery occur in approximately 1% to 6% of patients. A recent review reports 2.05% to 5.2% for laparoscopic Roux-en-Y gastric bypass (RYGB) and 1.68% to 2.6% for open RYGB. Additionally, sleeve gastrectomy has an associated leak rate up to 5.1%. The frequency with which leaks occur at different sites is not specified in most studies. A study by Ballesta and colleagues reported their experience regarding bariatric leaks by specific location: 68% at the gastrojejunostomy, 10% at the gastric pouch staple line, 3% at the remnant stomach staple line, 5% at the jejunojejunostomy, and the remaining 14% at combinations of these. Carruci and colleagues reported that in 48 patients from 906 primary RYGB operations, 77% of leaks occurred at the gastrojejunal anastomosis, whereas the remaining leaks were at the blind limb, jejunjejunostomy, and remnant gastric staple line. In general, it is accepted that the gastrojejunostomy anastomosis is the site most prone to leak, because it is the most commonly noted site in many large series.




Incidence


Leaks after bariatric surgery occur in approximately 1% to 6% of patients. A recent review reports 2.05% to 5.2% for laparoscopic Roux-en-Y gastric bypass (RYGB) and 1.68% to 2.6% for open RYGB. Additionally, sleeve gastrectomy has an associated leak rate up to 5.1%. The frequency with which leaks occur at different sites is not specified in most studies. A study by Ballesta and colleagues reported their experience regarding bariatric leaks by specific location: 68% at the gastrojejunostomy, 10% at the gastric pouch staple line, 3% at the remnant stomach staple line, 5% at the jejunojejunostomy, and the remaining 14% at combinations of these. Carruci and colleagues reported that in 48 patients from 906 primary RYGB operations, 77% of leaks occurred at the gastrojejunal anastomosis, whereas the remaining leaks were at the blind limb, jejunjejunostomy, and remnant gastric staple line. In general, it is accepted that the gastrojejunostomy anastomosis is the site most prone to leak, because it is the most commonly noted site in many large series.




Diagnosis


Bariatric leaks are feared in part due to the challenge in making the diagnosis as well as the significant mortality rate that accompanies this complication. In some series, the death rate in patients presenting with a leak after bariatric procedures can be as high as 6%. In contrast to the nonobese population, bariatric patients with a leak often present without fever, leukocytosis, or abdominal pain. These classic signs of viscous perforation are not reliable in the obese population. In addition, because of patient size, available radiographic imaging options, including upper gastrointestinal imaging (UGI) and CT scans, are of limited quality. In many patients, the only sign of a postsurgical leak is sustained tachycardia. Gonzalez and colleagues reported that tachycardia (>100) was the only consistently present indicator in 72% of patients with a confirmed leak. In this study, fever and leukocytosis were present in 62% and 48%, respectively. Carruci and colleagues also noted that tachycardia was present in an overwhelming number (92%) of leak patients. Nausea and vomiting were the next most common symptoms in 81% of that study group.


The primary radiologic techniques used in the diagnosis of bariatric leaks are UGI and CT scans. Because of patient obesity, both of these tests have limited diagnostic sensitivity when used on routine basis; nevertheless, these studies do have a high predictive value when they are positive. Despite these limitations, radiologic evaluation is important in the early detection of leaks in the postoperative setting. The primary diagnostic tool used to assess for postoperative leaks is a UGI study with an oral water-soluble contrast. This study is typically performed on postoperative day 1 or 2 and has shown variable sensitivity in detecting leaks. Reports as low as 33% leak detection have been published when UGI study is used routinely after gastric bypass operation. This is likely because many leaks occur after a UGI study has been performed. The greatest value of a UGI study is when it is done in patients with clinical suspicion for a leak. The sensitivity can be as high as 92% under these circumstances. The administration of oral methylene blue dye and observation of drain output can also be useful if a drain is left intraoperatively. Because of these diagnostic dilemmas, bariatric surgeons must rely on a combination of clinical suspicion and radiographic and laboratory evidence as well as vital sign trends to determine the possibility of a leak.


Another diagnostic approach to bariatric leaks is prophylactic placement of a drain at the time of surgery. In one study, 24% of leaks were detected by the observation of possible enteral content in the drain fluid. There remains much controversy on the use of drains and the duration of placement.




Standard treatment


Management of bariatric leaks has traditionally consisted of drainage, antibiotics, and specialized nutrition. Choice of drainage procedures is typically dictated by the condition of a patient and the characteristic of the leak—contained or free. In patients with hemodynamic instability, a surgical approach is preferred. In some series, the reoperative approach has been reported to be as high as 80%. This allows for abdominal washout, possible attempts at repair or patch, and placement of appropriate drains. It also provides the opportunity to obtain enteral access for nutrition. The disadvantages of this approach include wound infection, dehiscence, hernia, feeding tube complications, and abdominal compartment syndrome. In a hemodynamically stable patient with controlled sepsis, a percutaneous approach is preferred if radiographically accessible. This avoids the morbidity associated with an additional operation although it negates the opportunity for feeding tube placement. Nutritional alternatives in these patients are typically limited to the total parenteral route. Parenteral nutrition is not optimal due to its expense and inherent risks of vascular thrombosis and line sepsis and lower efficacy compared with enteral feedings.


In recent years there has been an increase in the nonoperative management of leaks after gastric bypass as most leaks are well contained and do not require operative control. In one series of 46 bariatric leaks, 40 were contained. Of these contained leaks, 33 could be treated without reoperation. Nonoperative treatment consisted of nothing by mouth, antibiotics, and specialized nutrition. Serial UGI studies were performed until radiologic closure was documented. Using this approach, radiologic resolution of the leak occurred at a median of 17 days, when oral intake could be started. There was no mortality in this study. The nonoperative strategy in this study required the drain to be left in place at least 1 week after surgery.




The use of stents


A possible adjunct in managing postsurgical leaks involves minimally invasive techniques using stents placed with endoscopic and fluoroscopic guidance. Covered stents can be placed in the bowel lumen at the site of the leak in a minimally invasive fashion. Stents offer several treatment advantages that can simplify surgical management of postoperative leaks. A stent prevents or greatly diminishes further peritoneal contamination by excluding the leak site from enteral secretions. This in turn is thought to promote and accelerate leak healing. Stent placement results in a rapid improvement in abdominal pain as a result of decreased peritoneal contamination. Shielding of the leak site also permits nutrition to be given orally in many cases. Parenteral nutrion is seldom necessary. Fig. 1 illustrates prestent and poststent treatment of a gastroejunal anastomotic leak.


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Sep 12, 2017 | Posted by in GASTOINESTINAL SURGERY | Comments Off on Management of Postsurgical Leaks in the Bariatric Patient

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