10. Managing Gastroparesis in the Setting of Obesity
KeywordsObesityMorbid obesityGastroparesisRoux-en Y gastric bypassSubtotal gastrectomyPartial gastrectomyBody mass indexSleeve gastrectomy
Gastroparesis is a chronic neuromuscular disorder of the upper gastrointestinal tract characterized by delayed gastric emptying in the absence of obstruction. Common symptoms of gastroparesis include nausea, vomiting, bloating, early satiety, and abdominal pain. Although the pathophysiology of gastroparesis is poorly understood, it is estimated that approximately ten million adults have symptoms of gastroparesis. The most common etiologies of gastroparesis are idiopathic (36%), followed by diabetes (30%) and postsurgical (19%) [1–7]. Diagnosis of the disorder is made by clinical history and confirmed objectively with a four-hour solid-phase scintigraphic emptying scan demonstrating >10% gastric retention [1, 3–5]. Treatment of gastroparesis typically focuses on symptom management utilizing dietary modification, prokinetic and antiemetic medications, and diabetes control. Surgery is reserved for gastroparesis refractory to medical management. Response to any treatment modality has been shown to vary depending on the etiology of gastroparesis, with idiopathic being less responsive overall compared to postsurgical or diabetic gastroparesis. Abdominal pain is the least likely symptom to improve . Common operations such as gastric fundoplication, paraesophageal hernia repair, vagotomy for ulcer disease, and gastric reconstructions may result in postsurgical gastroparesis [4, 5].
Surgical interventions for refractory gastroparesis include gastric electrical stimulation (GES), laparoscopic pyloroplasty, and peroral endoscopic pyloromyotomy (POP), GES plus pyloroplasty, total/subtotal gastrectomy, and laparoscopic Roux-en-Y gastric bypass [3–6, 8–12]. In recent years, laparoscopic sleeve gastrectomy has also been suggested as a therapy for gastroparesis and is the subject of ongoing investigation . While this procedure may accelerate gastric emptying, it is also known to predispose patients to GERD, which is a frequent complaint with gastroparesis. Published outcomes suggest that all of these procedures can have a positive therapeutic effect in minimizing patient symptoms; however, due to limited subject numbers and a paucity of comparative data, there is no consensus on the surgical procedure of choice. Studies focus on improvement in patient symptoms (nausea, vomiting, abdominal pain), Gastroparesis Cardinal Symptom Index (GCSI) scores, and objective improvement in gastric emptying studies .
When considering surgical therapy for gastroparesis, the presence of obesity may affect treatment choice. Many patients with gastroparesis are obese, while a few are underweight, and obesity is a strong independent predictor of the presence of symptoms in patients with gastroparesis [13, 14]. Given the current epidemic of obesity, its effects on gastroparesis are becoming increasingly relevant. This is particularly important as the proportion of associated comorbidities of overweight (BMI 25–29.9 kg/m2) and obesity (BMI ≥ 30 kg/m2) are rising in patients with both type II and type I diabetes mellitus. Because of this partial gastrectomy with Roux-en-Y reconstruction (termed by some as a “last resort” or “end of the road” surgical treatment for refractory gastroparesis) has been suggested as the preferred treatment option in patients with obesity (BMI ≥ 35 kg/m2) and medically recalcitrant gastroparesis [10, 12]. Although controversial, the operation has been described with (leaving a duodenal stump) and without (i.e., gastric bypass) removal of the remnant stomach [10, 12]. Compared to laparoscopic gastric bypass, laparoscopic subtotal gastrectomy is a more extensive operation requiring greater operative time and added risk related to the removal of the gastric remnant. While there may be less risk associated with laparoscopic gastric bypass when compared to laparoscopic subtotal gastrectomy, it is not known what effect the in situ gastric remnant may have on postoperative symptoms. Comparative trials do not exist, and both approaches are commonly utilized.
A small number of studies have looked at the effectiveness of laparoscopic subtotal gastrectomy and laparoscopic gastric bypass on gastroparesis symptom reduction and/or compared the procedure(s) to laparoscopic gastric electrical stimulator (GES) placement, which has been shown to result in symptom improvement [3–6, 10, 12]. In a retrospective chart review of 103 patients undergoing laparoscopic subtotal gastrectomy (n = 31) vs. GES implantation (n = 72), there was no difference in GCSI between the two groups. However, there were 19 treatment failures in the GES group, and of these, 13 were converted to subtotal gastrectomy with 100% symptom improvement . Similar results showing the effectiveness of both GES and laparoscopic RYGB without significant differences in postsurgical complications but with higher rates of reoperation for GES have been demonstrated . Another retrospective study comparing GES to Roux-en-Y gastrojejunostomy with or without subtotal gastrectomy in morbidly obese patients demonstrated that both procedures provide effective symptom control and that patients who fail GES implantation can be successfully converted laparoscopically to Roux en Y gastrojejunostomy (RYGJ) with subsequent symptom improvement. The authors acknowledge that the retrospective nature and small sample size are weaknesses of the study but proposed RYGJ as the first-line surgical therapy for gastroparesis .
Laparoscopic gastric bypass has also been evaluated in a small retrospective study evaluating its use in obese and morbidly obese patients who previously failed GES implantation. In this study, symptoms of recalcitrant idiopathic or diabetic gastroparesis were evaluated in seven obese and morbidly obese patients (mean BMI 39.5 kg/m2, range 33–54 kg/m2, six women) before and after gastric bypass. Laparoscopic conversion of GES to Roux-en-Y gastric bypass resulted in marked symptom improvement with significantly decreased total symptom scores. Surgery also resulted in a mean postoperative BMI decrease of 9.1 kg/m2 with 71.6% excess body weight loss at a mean follow-up of 315 days (range 153–739). More than half of the patients (four) were taking prokinetic agents preoperatively, and no patients required them postoperatively. In addition, preoperative gastroesophageal reflux disease (GERD) symptoms resolved in five of six patients, hypertension resolved in three of four patients, and both diabetic patients experienced improvement in their diabetes following gastric bypass. No acute perioperative complications occurred, and the study concluded that laparoscopic Roux-en-Y gastric bypass can safely reduce gastroparesis symptoms and that larger prospective studies with longer follow-up are needed .
Considering the significant benefit in diabetes control, weight loss, and improvement in gastric emptying, laparoscopic Roux-en-Y gastric bypass appears to be particularly well suited for the obese, diabetic patient with refractory gastroparesis. A small number of studies exist that demonstrate the effectiveness of laparoscopic gastric bypass when compared to gastric electrical stimulation; however, they share weaknesses in terms of small sample size and their retrospective nature. Although laparoscopic Roux-en-Y gastric bypass is known to be a safe and effective procedure for weight loss, proper patient selection is important, and many patients may not be good candidates for a gastric bypass. As with any weight loss procedure and surgical intervention for gastroparesis, proper preoperative patient counseling and the establishment of reasonable expectations are important.