Dumping Syndrome After Gastric Bypass (RYGB)
Obesity is one of the most significant health problems worldwide, and the prevalence has been increasing over the past decade. Despite improvement in the performance of bariatric surgery, complications are not uncommon. These complications vary according to baseline patient characteristics, the duration of time since the operation, and the type of bariatric surgery performed. Endoscopy is the cornerstone in the diagnosis of postoperative complications after bariatric surgery, and may even be performed in the early postoperative course. With an increasing number of patients being referred for endoscopic evaluation following bariatric surgery, it is essential to develop an understanding of the anatomic changes for optimal assessment and appropriate treatment of these patients.
Early and late dumping syndrome occurs not uncommonly in patients who have undergone gastric bypass surgery when large quantities of simple carbohydrates are ingested. Early dumping typically occurs within 15 minutes of ingestion and has been attributed to rapid fluid shifts from the plasma into the bowel from hyperosmolality of the food. Late dumping occurs hours after eating and results from hyperglycemia and the subsequent insulin response leading to hypoglycemia. When hypoglycemia is severe, treatment with a low carbohydrate diet and an alphaglucosidase inhibitor may be effective. Furthermore, restoration of gastric restriction using an endoscopic approach to reduce the aperture of the GJA has also demonstrated to be effective in management of this condition.
The initial management of dumping syndrome is dietary modifications. Recommendations include consuming smaller meals by dividing daily calorie intake into six meals and delaying liquids at least 30 min after meals Rapidly absorbable simple carbohydrates should also be avoided. Adjuncts to diet modification include pectin and guar gum, which slow down gastric emptying by increasing food viscosity. Acarbose, which interferes with carbohydrate absorption in the small intestines, has also proven to relieve symptoms in small studies. After dietary modifications, medications such as somatostatin analogs (e.g., octreotide) alleviate symptoms by delaying gastric emptying and small bowel transit time, as well as inhibiting gastric hormones and insulin secretion. Multiple studies have evaluated both short- and longterm somatostatin therapies, with results showing sustained symptom control in patients refractory to dietary modifications. In severe cases refractory to medical management, surgical interventions, such as narrowing of the anastomosis, conversion of the prior bariatric surgery, and using jejunostomy parenteral feeding, may help. Follow-up with gastrointestinal specialists and the patient’s bariatric surgeon is strongly recommended if dumping syndrome is suspected.
An important metabolic complication which is attracting increasing interest is postprandial hyperinsulinemic hypoglycemia (PHH), characterized by hypoglycemic symptoms developing 1–3 h after a meal accompanied by a low blood glucose level. This condition should be distinguished from early dumping syndrome where symptoms develop within minutes to 1 h after a meal of caloric dense food, caused by the rapid and unregulated emptying of food into the jejunum, which induces rapid fluid entry into the small bowel. Early dumping often occurs early in the postoperative period, most commonly after Roux-en-Y gastric bypass, whereas PHH may develop months to years after surgery.
Symptoms related to post-PHH usually develop late after surgery in contrast to early dumping. Symptoms are wide ranging, but are usually related to Whipple’s triad: symptomatic hypoglycemia, a low plasma glucose level, and resolution of symptoms after the administration of glucose. Symptoms of hypoglycemia may include anxiety, sweating, tremors, palpitations, confusion, weakness, lightheadedness, dizziness, blurred vision, disorientation, and possibly loss of consciousness.
Because of variability in degree of symptoms and the absence of a clear pathophysiology, management of this condition can be challenging. Fortunately, a significant percentage of patients with milder forms of the condition can be managed with dietary modifications consisting of frequent small meals with a low glycemic index. This requires supervision by a dietitian and long-term patient compliance. Additional benefit has been obtained by the addition of acarbose, an α glucosidase inhibitor in doses 100–300 mg. Successful management has been also reported in case reports or small case series with diazoxide, calcium channel blockers, and somatostatin analogues. The role of GLP-1 in the pathogenesis of this condition is supported by the observation that infusions of GLP-1 antagonists corrected hypoglycemia in these patients. These agents are investigational at present, but provide opportunity for additional future treatment approaches. For patients with persistent symptoms despite medical treatment, reversal of the bariatric procedure should be considered. Partial pancreatectomy, although used in the past, is now not recommended because of the significant morbidity and poor long-term symptom control. Postprandial hyperinsulinemic hypoglycemia is an important, potentially dangerous late complication of metabolic surgery. Successful diagnosis and management of this condition requires multidisciplinary specialty resources and essential long-term follow-up capabilities.
Surgical management of GASTRIC CANCER
Laparoscopic versus Open gastrectomy
Surgery is the only curative therapy for gastric cancer but most operable gastric cancer presents in a locally advanced stage characterized by tumor infiltration of the serosa or the presence of regional lymph node metastases. Surgery alone is no longer the standard treatment for locally advanced gastric cancer as the prognosis is markedly improved by perioperative chemotherapy. The decisive factor for optimum treatment is the multidisciplinary team specialized in gastric cancer. However, despite multimodal therapy and adequate surgery only 30% of gastric cancer patients are alive at 3 years.
The same principles that govern open surgery is applied to laparoscopic surgery. To ensure the same effectiveness of laparoscopic gastrectomy (LG) as conventional open gastrectomy, all the basic principles such as properly selected patients, sufficient surgical margins, standardized D2 lymphadenectomy, no-touch technique, etc., should be followed.
LG may be considered as a safe procedure with better short-term and comparable long-term oncological results compared with open gastrectomy. In addition, there is HRQL advantages to minimal access surgery. There is a general agreement that a laparoscopic approach to the treatment of gastric cancer should be chosen only by surgeons already highly skilled in gastric surgery and other advanced laparoscopic interventions. Furthermore, the first procedures should be carried out during a tutoring program. Diagnostic laparoscopy is strongly recommended as the first step of laparoscopic as well as open gastrectomies. The advantage of early recovery because of reduced surgical trauma would allow earlier commencement of adjuvant chemotherapy and the decreased hospital stay and early return to work may offset the financial costs of laparoscopic surgery.
The first description of LG was given by Kitano, Korea in 1994 and was initially indicated only for early gastric cancer patients with a low-risk lymph node metastasis. As laparoscopic experience has accumulated, the indications for LG have been broadened to patients with advanced gastric cancer. However, the role of LG remains controversial, because studies of the long-term outcomes of LG are insufficient. The Japanese Gastric Cancer Association guidelines in 2004 suggested endoscopic mucosal resection or endoscopic submucosal dissection for stage 1a (cT1N0M0) diagnosis; patients with stage 1b (cT1N1M0) and cT2N0M0) were referred for LG. Totally laparoscopic D2 radical distal gastrectomy using Billroth II anastomosis with laparoscopic linear staplers for early gastric cancer is considered to be safe and feasible. Laparoscopy-assisted total gastrectomy shows better short-term outcomes compared with open total gastrectomy in eligible patients with gastric cancer.
There was a significant reduction of intraoperative blood loss, a reduced risk of postoperative complications, and a shorter hospital stay. Western patients are relatively obese and there is an increased risk of bleeding if lymphadenectomy is performed. LG is technically difficult in the obese than in the normal weight due to reduced visibility, difficulty retracting tissues, dissection plane hindered by adipose tissue, and difficulty with anastomosis. Open gastrectomy is thus preferable for the obese. However, obesity is not a risk factor for survival of patients but it is independently predictive of postoperative complications. Careful approach is being needed, especially for male patients with high body mass index.
Robotic surgery will become an additional option in minimally invasive surgery. The importance of performing effective extended lymph node dissection may provide the advantage of using robotic systems. Such developments will improve the quality of life of patients following gastric cancer surgery. A multicenter study with a large number of patients is needed to compare the safety, efficacy, value (efficacy/cost ratio) as well as the long-term outcomes of robotic surgery, traditional laparoscopy, and the open approach.