Article

Common weight loss procedures and their complications

a b s t r a c t

Background: As the number of obese patients in the United States continues to grow, there is a parallel increase in the number of bariatric surgery patients. A quarter of these patients will return to the Emergency Department (ED) within the first two years of the index procedure.

Objective: An understanding of the most common bariatric procedures and their related complications will great- ly aide the Emergency Medicine physician in the care of these patients.

Discussion: Abdominal pain is the most common reason for bariatric patients to present to the ED and can repre- sent a diagnostic challenge to EM physicians. It is important that EM physicians have a good understanding of bariatric procedures. We describe the three most common bariatric procedures: 1) the Laparoscopic Adjustable Gastric Banding (LAGB); 2) the Laparoscopic Sleeve Gastrectomy (LSG); 3) and the Roux-en-Y gastric bypass (RYGB). Due to the unique altered anatomy following the procedures there are specific complications related to each individual procedure. We will describe the most common presentations of abdominal pain in the post bariatric surgery patient. Finally, we will review new endoscopic procedures and the associated complications that may cause patients to present to the ED. Conclusion: Certain complications in bariatric surgery patients can have a high rate of morbidity and mortality. An improved understanding of bariatric procedures and their complications will allow for improved vigilance and management.

Introduction

Obesity has become an epidemic in the United States and around the world. Recent reports show that more than a third of the U.S. adult pop- ulation is now considered obese [1]. As bariatric surgery is shown to be the only effective, sustainable treatment for obesity and obesity related co-morbidities [2], the number of weight reduction surgeries is increas- ing at a rapid rate. In 2013, there were N 179,000 bariatric procedures performed in the United States [3]. The utilization of the Emergency De- partment (ED) by patients after bariatric surgery is growing at a rapid rate [4] with 26% of patients returning to the ED within the first two years post-operatively [5]. Thus proper management necessitates a baseline level of practitioner awareness of bariatric complications and anatomic considerations. Abdominal pain poses diagnostic challenges to the Emergency Medicine (EM) physician. The bariatric patient pre- sents a special challenge due to altered anatomy from the respective procedures that can lead to unique complications. differential diagnoses range from benign to life-threatening conditions, thus vigilance is need- ed when evaluating these patients. This article will review the current

? Disclosure: The authors have no relevant disclosures.

* Corresponding author at: 101 Nicolls Road HSC T18-040, Stony Brook, NY 11794, United States.

E-mail address: [email protected] (M.S. Altieri).

state of bariatric surgery and provide a synopsis of important diagnoses for EM physicians to consider when evaluating these patients.

Discussion

The three most common bariatric procedures currently are the lapa- roscopic sleeve gastrectomy (LSG), laparoscopic Roux-en-Y Gastric By- pass (LRYGB), and the laparoscopic adjustable gastric band (LAGB). While historically the LRYGB was the most commonly performed proce- dure, LSG is now gaining popularity due to its perceived low rate of post-operative complications. The LAGB has fallen out of favor due to band related complications and the need for re-operation in up to 52% of patients [6-8]. Others procedures, such as the Vertical Banded Gastroplasty (VBG) or Biliopancreatic Diversion-Duodenal Switch (BPD-DS) (Fig. 1) are now rarely performed. Additionally, newer endoscopic procedures, such as the gastric balloon, are gaining popularity.

Complications

Outcomes following weight loss procedures have dramatically im- proved over the last decade. The majority of patients are now

https://doi.org/10.1016/j.ajem.2017.11.050

discharged within two days post operatively and mortality is now b 1%. However, morbidity is up to 13% in some series [2,9].

A significant portion of these patients (~20%) return to the ED or are re-admitted [5,10]. Common reasons for return are abdominal pain (46%), emesis (38.5%) and dehydration (30.8%) [11,12]. As procedures differ, unique diagnoses must be considered when encountering these patients. The most common potential diagnoses for abdominal pain spe- cific to each bariatric procedure will be reviewed in this article. Bariatric surgery patients should be managed in conjunction with a bariatric sur- geon as soon as possible.

Laparoscopic adjustable gastric banding

The laparoscopic adjustable gastric banding (LAGB, Fig. 1) is falling out of favor due to the need for revision and conversion to other procedures in one in five patients [8] . Despite this, the number of patients with these devices is still significant and EM physicians should be familiar with the procedure and its complications. Common complications following gas- tric banding include band slippage/migration, overtightening (proximal gastric obstruction), and erosion into the stomach [13].

Band slippage

Band slippage or prolapse occurs when the wall of the stomach mi- grates upward through the band. It is reported with an incidence of up to 22% [14]. With most band slippage patients, symptoms tend to be non-specific, such as abdominal pain, nausea, vomiting. It can also pres- ent with the heartburn and reflux. Although this may be diagnosed on a plain X-ray, it is more reliably diagnosed by performing a fluoroscopic water-soluble contrast swallow study. The diagnosis on an AP abdomi- nal radiograph includes measurement between the longitudinal axis of the gastric band and the spinal column which is referred as the phi angle. The phi angle should be between 4 and 58 [15]. A normal position of a band is shown on Fig. 2. Band slippage may resolve with removal of the fluid from the subcutaneous port. The port can be accessed and decompressed with a Huber needle. If slippage does not resolve after decompression, surgery is indicated.

Band erosion

The incidence of band erosion can be as high as 11% and usually oc- curs within the first two years following the index procedure [16]. Al- though patients can be asymptomatic or present with decreased restriction, patients can also present to the ED with vague Epigastric pain, bleeding, port-site infection, or intraAbdominal abscess. Thus a high index of suspicion is necessary when seeing these patients. Diagno- sis can be made with Computed Tomography (CT) scan with PO con- trast, upper GI or Upper endoscopy, which can provide a definitive diagnosis and treatment. Emergent surgery is seldom needed for a band erosion, as the process usually occurs over weeks to months, thus it is usually a Contained perforation. However, if patient is unstable or had peritoneal signs, urgent surgical intervention is required.

Laparoscopic sleeve gastrectomy

Laparoscopic sleeve gastrectomy (LSG) is now the more popular pro- cedure for definitive weight loss due to its simplicity, low long-term com- plication rate, and acceptable weight loss [17-19]. LSG involves the excision of the greater curvature of the stomach, leaving a tubular stom- ach (Fig. 1). Although thought to be associated with lower rates of compli- cations, up to 10.5% of patients following sleeve gastrectomy return to ED in the 30-day post-operative period [20]. Complications that one may en- counter in the ED include staple line leaks and strictures.

Staple line leak

Staple line leak following LSG is one of the most important and mor- bid complications with an incidence of up to 3% for primary procedures and N 10% in revisional procedures [21-23]. Leaks tend to occur within a week after surgery, however late leaks have also been reported (Fig. 3). Presentation can range from mild discomfort to sepsis and peritonitis. Unexplained fever or tachycardia have been shown to be associated with presence of gastric leak [24,25]. Leaks can also present as a pleural effusion. In the stable patient, laboratory work up and Computed To- mography (CT) with PO water soluble contrast can be obtained to con- firm the diagnosis. CT should detect a leak in 86% of cases [26]. Others

Fig. 1. Bariatric procedures. a) Duodenal switch b) Gastric banding c) Roux-en-Y Gastric Bypass d) Sleeve Gastrectomy.

Small bowel obstruction/internal “>argue that an upper Gastrointestinal (UGI) Series or endoscopy may be necessary to detect a leak given the high morbidity associated with a missed diagnosis [27]. We recommend that a CT scan with PO water sol- uble contrast be performed first to rule out other pathologies in addition to possibly confirm the diagnosis.

Strictures. Strictures can present in a delayed fashion following LSG and can be due to kinking or twisting of the tubular pouch, ischemia or a leak. The most common location is at the incisura angularis [28]. Their presentation involves inability to tolerate oral intake, dysphagia, reflux, or nausea and/or vomiting. An upper GI series or endoscopy is usually diagnostic. Strictures can be managed either surgically or endoscopically.
1. Roux-en-Y gastric bypass
  When evaluating the patient who has undergone Roux-en-Y Gastric Bypass, certain considerations regarding anatomy of the procedure should be considered (Fig. 1). Initial evaluation includes vital signs, physical exam and basic labs including a CBC, chemistry, and lactic acid. Type and screen should be considered if there is a concern that the patient may require operative intervention. While evaluating the patient, one should ensure that there is no hemodynamic instability or peritonitis. If present, the patient should be fluid resuscitated and an emergent surgical consult should be called. If patient is hemodynami- cally stable a Computed Tomography (CT) scan can be performed, which can either confirm the diagnosis or exclude other pathologies.
  
  Staple line leak
  
  Staple line (anastomotic) leak is an early complication following RYGB that is associated with a high rate of morbidity and mortality [29]. The in- cidence of anastomotic leak has significantly decreased in recent years
  
  [30] and are now usually reported in least than 2%. In a retrospective
  
  study of 59 patients, the majority of leaks were at the gastrojejunostomy
  
  (GJ) site and were diagnosed within 48 h of surgery. However, a signifi- cant portion (57.6%) were diagnosed on readmission, thus a patient with a leak can present to the emergency department [29].A history of an upper GI series either intra-operative or immediately post- operatively does not rule out the diagnosis of a staple line leak and the EM physician should be aware of this complication. Staple line leak usual- ly presents within the first 10 days following surgery. The most common symptoms at diagnosis are abdominal pain, fever, tachycardia, nausea and vomiting, oliguria, and hemodynamic instability with hypotension [29]. Patients also typically report a “feeling of impending doom.” An upper GI (UGI) series can help with diagnosis, however if peritonitis or hemody- namic instability is present, emergent surgery may be required and ag- gressive resuscitation should be provided while awaiting diagnosis confirmation and definitive management.
  Small bowel obstruction/Internal hernia
  1. Presentation. Compared to the LAGB or LSG, the rerouting in RYGB creates potential spaces where bowel loops can be trapped and create an internal hernia. Abdominal pain accompanied by nausea and vomiting in this patient population is not only concerning for a small bowel obstruction, but for potential internal hernia. Internal hernia is a well-recognized complication following RYGB and incidence ranges between b 1% to 16% [31-34] and a high mortality rate exceeding 50% may occur if strangulation is present [35,36]^. Internal hernia can occur at any time following procedure.
  In some cases, patients can present with vague complaints. Similarly, physical exam can range from a benign abdomen to peritonitis. Vital signs can be normal, although tachycardia can be present due to dehy- dration. Laboratory studies should be obtained, in addition to a plain ra- diograph to evaluate for intraluminal fluid levels, dilated loops of bowel, or pneumatosis. In a recent retrospective study, there was no difference between patients with or without an internal hernia in terms of location of abdominal pain, leukocytosis, or tachycardia, however neutrophilia (defined as neutrophils N 65%) was significantly associated with the presence of an internal hernia [37]. Computed Tomography (CT) with PO and intravenous (IV) contrast can be performed in the hemodynam- ically stable patient. There are several findings on a CT scan that can be suggestive of internal hernia. These include signs of small bowel
  
  Fig. 2. Proper position of LAGB. Fig. 3. Leak following sleeve gastrectomy.
  
  obstruction, small bowel loops in the upper quadrants, evidence of small bowel mesentery crossing the transverse mesocolon, twisting, swirling of mesenteric vessels (Fig. 4), or engorgement of the mesenter- ic vessels. A negative CT scan should not preclude the diagnosis of an in- ternal hernia, as a recent study found that 22.2% of patients with an internal hernia on exploration had a negative CT scan during their visit to the ED [37]. Any concern for an internal hernia in this patient population merits an urgent surgical evaluation.
  - Marginal ulceration. Marginal Ulceration at the gastrojejunal (GJ) anastomosis following RYGB is another well recognized complication with an incidence of 1-16% after open gastric bypass and 7% after lapa- roscopic RYGB [38,39]. Many causes for development of marginal ulcer- ation have been described [40-42]. The symptoms of marginal ulcers can include vague abdominal pain, nausea, vomiting, heartburn, dys- phagia, and bleeding. The preferred method of evaluation in the hemo- dynamically stable patient is an upper endoscopy after all other work up has been negative, although the endoscopy is typically performed on an outpatient basis. The patient can be discharged home with misoprostol, a proton pump inhibitor (PPI) and Carafate. In the setting of bleeding or potential perforated marginal ulcer, urgent management is required.
  1. Newer endoscopic procedures
  Recently, newer endoscopic obesity procedures have been approved by the FDA for the management of obesity. These approved devices are for patients with BMI 30-40 kg/m2. Orbera(TM), ReShape(R) Dual Balloon and the Obalon device are the three approved balloon systems (Fig. 5a). Cramping, nausea and vomiting and reflux are common side effects following gastric balloon insertions, thus these patients can pres- ent to the ED with these symptoms. However, there have been reports of gastric balloon migration and subsequent small bowel obstruction in a small subset of patients [43]. intravenous hydration and radiologic studies to confirm the diagnosis may be necessary if concerns for migra- tion exist. In case of migration, emergent surgery may be necessary to remove the balloons and manage possible obstruction.
  1. Aspiration therapy
  Recently approved in the US, AspireAssist siphon assembly (Aspire Bariatrics, King of Prussia, PA) consists of an endoscopically placed Gastrostomy tube to aspirate gastric contents 20 min following a meal (Fig. 5b). Although common complications are minor, such as pain around site, nausea/vomiting, irritation, bleeding, infection [44], the po- tential of gastrostomy tube dislodgement and peritonitis should be
  
  Fig. 4. Swirling of mesenteric vessels concerning for internal hernia.
  
  considered in a patient who is presenting with hemodynamic instabili- ty, sepsis, and/or peritonitis following placement in the first three to four post-operative weeks. Labs, imaging, and emergent surgery may be necessary.
  
  Conclusion
  
  As the number of bariatric surgery procedures increases, the number of patients presenting to the ED with bariatric surgery complications will likely increase as well. The EM physician should be familiar with the most common bariatric procedures and the associated differential diagnoses for abdominal pain in this patient population. Vigilance is re- quired when caring for these patients as the etiology for abdominal pain can range from benign to fatal. It is important to have a low threshold to involve the bariatric surgeon, as standard ED workup (labs, US and CT) can miss critical diagnoses. Appropriate resuscitation and source control may be necessary while awaiting definitive diagnostic workup and management.
  
  Fig. 5. New endoscopic devices for weight loss.
  
  References
  surgery worldwide 2013. Obes Surg 2015;25(10):1822-32.
  99(4):279-83.
  Lange; 2007.

AJEM

Common weight loss procedures and their complications