The association between GERD and obesity has generated great interest, because obesity has been indicated as a potential risk factor for reflux disease. A directly dependent relationship has been reported because an increase in body mass index has mirrored an increase in the risk of GERD. The incidence of reflux in the obese population has been cited as high as 61%. The pathophysiologic mechanism underlying the link between obesity and GERD has not been fully elucidated and seems to be multifaceted. As the number of obese patients is increasing, so is the volume and variety of bariatric procedures. The effect of bariatric surgery on preexisting GERD or newly developed GERD differs by procedure.
GERD AFTER ROUX-EN-Y GASTRIC BYPASS
Roux-en-Y gastric bypass (RYGB) has been used as a standalone reflux procedure. Mechanisms of the antireflux effect of RYGB include diverting bile from the Roux limb, promoting weight loss, lowering acid production in the gastric pouch, rapid pouch emptying, and decreasing abdominal pressure over the LES. Several studies have examined the relationship between GERD and RYGB. Studies have also analyzed symptomatic relief by using questionnaires before and after the procedure. One study has examined further the incidence of esophagitis postoperatively on endoscopy. Merrouche and colleagues showed a 6% incidence of esophagitis on endoscopy after RYGB; however, the preoperative incidence was not mentioned.
Pallati and colleagues also examined the GERD symptoms after several bariatric procedures by using the Bariatric Outcomes Longitudinal Database. GERD score improvement was highest in the RYGB group; 56.5% of patients showed improvement of symptoms. The study concluded that RYGB was superior to all other procedures in improving GERD. The proposed but unproven mechanisms included a greater weight loss and a decrease in the amount of gastric juice in the proximal pouch. The study, however, did not show any objective measures of GERD improvement. Another study by Frezza and colleagues showed a significant decrease in GERD-related symptoms over the 3-year study after laparoscopic RYGB, with decrease in reported heartburn from 87% to 22% (P<.001). The authors proposed that, in addition to volume reduction and rapid egress, the mechanism of how this procedure affects symptoms of GERD is through weight loss and elimination of acid production in the gastric pouch. The gastric pouch lacks parietal cells; thus, there is minimal to no acid production and also, owing to its small size, it minimizes any reservoir capacity to promote regurgitation.
Varban and colleagues examined the utilization of acid-reducing medications (proton pump inhibitor and H2-blockers) at 1 year after various bariatric procedures. The groups reported that at 1 year after RYGB, 56.2% of patients would discontinue an acid-reducing medication that they had been using at baseline. Interestingly, the group also showed that 19.2% of patients would also start a new acid-reducing medication after RYGB. Given the number of studies that have reported improvement in GERD symptoms after RYGB, this procedure is now widely accepted as the procedure of choice for treatment of GERD in the morbidly obese patient. Although no increased risk is conferred to patients with a body mass index of 35 kg/m2 or higher who undergo fundoplication for GERD the recommendation and practice of many surgeons is to perform a laparoscopic gastric bypass in lieu of fundoplication owing to its favorable effect on other comorbid conditions. In addition, advocates of the RYGB are promoting a conversion to an RYGB instead of a redo fundoplication.
In a recent study, Stefanidis and colleagues followed 25 patients who had previous failed fundoplication, which was taken down and converted to an RYGB. Patients were followed with the Gastrointestinal Quality of Life Index and the Gastrointestinal Symptoms Rating Sale. The revision surgery led to resolution of GERD symptoms for a majority of the patients. The authors concluded that an RYGB after a failed fundoplication has excellent symptomatic control of symptoms and excellent quality of life. However, owing to the technical challenges of the procedure and the potential for high morbidity, it should only be performed by experienced surgeons.
GERD AFTER SLEEVE GASTRECTOMY
Sleeve gastrectomy (SG), which was originally described as a first stage of the biliopancreatic diversion, is a relatively new treatment alternative for morbid obesity. It has become popular owing to its technical simplicity and its proven weight loss outcomes. Although it has many positive effects on obesity and obesity-related comorbidities, the association between GERD and SG remains controversial. Although some studies have reported improvement in GERD symptoms after SG, the majority of studies have reported an increase in GERD symptoms. The International Sleeve Gastrectomy Expert Panel reported a postoperative rate of GERD symptoms after SG in up to 31%; however, others cited increased GERD prevalence after surgery between 2.1% and 34.9%.
Studies Showing an INCREASE: Several studies have shown an increase of GERD after SG at various time points. The comparison between different studies is difficult owing to variations in the definition of GERD. Although some have utilized the use of proton pump inhibitors as a diagnostic tool, others have used the definition of typical heartburn and/or acid regurgitation occurring at least once per week. Few studies used objective data to define reflux.
Tai and colleagues examined symptoms of GERD and erosive esophagitis at 1 year after laparoscopic sleeve gastrectomy (LSG). The groups concluded that there was a significant increase in the prevalence of GERD symptoms and erosive esophagitis (P<.001), in addition to a significant increase in the prevalence of hiatal hernias (P<.001), which was higher in patients who presented with erosive esophagitis after LSG. Others have shown a similar increase of GERD at 1 year. Himpens and colleagues compared adjustable gastric banding (AGB) and SG at 1 and 3 years after procedures. GERD seemed de novo after 1 year in 8.8% and 21.8% of patients with AGB and SG, respectively. At 3 years, however, rates changed to 20.5% and 3.1% in the ABG and SG groups. Another study followed patients for more than 6 years and reported 23% to 26% of patients reporting frequent episodes of GERD. Various mechanisms have been postulated to cause symptoms of GERD after LSG. As SG alters the gastroesophageal anatomy, it has been hypothesized that the anatomic abnormalities created contribute to the development of GERD in patients.
Lazoura and colleagues showed that the final shape of the sleeve can influence the development of GERD. The group showed that patients with tubular pattern and inferior pouch (preservation of the antrum) did better in terms of regurgitation and vomiting compared with a tubular sleeve with a superior pouch. Others have also suggested the importance of antral preservation to avoid GERD development. An increase in acid production capacity can cause reflux in the case of an overly dilated sleeve, whereas impaired esophageal acid clearance can lead to reflux in a smaller sleeve. Formation of a neofundus can in an effort to avoid fistulas may also lead to development of GERD. Daes and colleagues further concentrated on describing and standardizing the procedure to reduce GERD symptoms. The authors identified 4 technical errors that led to development of GERD after the procedure: relative narrowing at the junction of the vertical and horizontal parts of the sleeve, dilation of the fundus, twisting of the sleeve, and persistence of hiatal hernia or a patulous cardia. By ensuring careful attention to surgical technique and performing a concomitant hiatal hernia repair in all patients, they reduced the rate of postoperative GERD to only 1.5%. The group concluded that hiatal hernia is the most important predisposing factor.
Studies Showing REDUCTION: Several studies have reported either decreased or no association between GERD and LSG. Interestingly, in some of these studies, GERD improvement has been reported as a secondary outcome. Rawlins and colleagues reported an improvement of symptoms in 53% of patients, but de novo GERD in 16% of patients. A multicenter prospective database review examined GERD in all 3 major bariatric procedures and reported improvement in all. The authors used medication use to define GERD. A small portion of patients reported worsening GERD, which was highest in the SG group. Sharma and colleagues also reported an improvement of GERD as assessed by symptom questionnaires, as well as improvement in grade of esophagitis on endoscopy. The possible mechanisms for improvement of GERD postoperatively are faster gastric emptying, reduction in gastric reservoir function, gastrointestinal hormonal modifications, decrease in acid secretions, and decrease in weight. Daes and colleagues reported a decrease in incidence of GERD by using a standardized operative technique and concomitant repair of hiatal hernia.
Owing to conflicting reports about the association between GERD and LSG, this procedure is controversial in patients with preexisting GERD. If LSG is considered in this population, hiatal hernia repair and meticulous technique are essential. We would like to emphasize the importance of preoperative testing to define the anatomy and evaluate preexisting GERD, esophagitis, Barrett’s esophagus, or the presence of hiatal hernia.
The incidence of HCC is increasing in the worldwide. Surgery in the form of liver resection or transplantation remains the mainstay of curative treatment for HCC, even though selected patients with small tumours may also be cured with ablation. Liver resection and transplantation are not necessarily two binary choices in most patients and, despite all the debates, are often complementary treatment modalities ideally suited to different patient groups. Thus characterisation of patient and tumour characteristics to guide decision making is vital to achieve the best outcome for patients.
1.Anatomical Resection or Not?
The aim of liver resection in patients with HCC and CLD is that it should be curative with resection of tumour vascular territories and also preserve as much liver volume as possible to prevent postoperative liver failure. EASL guidelines recommend anatomical resection of HCC, whereby the lines of resection match the limits of one or more functional segments of the liver. This is based on evidence suggesting superior oncological outcomes in addition to a reduction in the risk of bleeding and biliary fistula. Although there are no randomised data, a meta-analysis including 2000 patients from 12 non-randomised comparative trials did not show any benefit of anatomical compared with non-anatomical resection in 1-, 3- and 5-year survival, recurrence rate, postoperative morbidity or blood loss . It is practice to perform an anatomical resection for tumours >2 cm, and for smaller tumours in anatomically favourable positions, a wedge with adequate margin is often sufficient. Modifying techniques to maximise parenchymal preservation preserving adequate margins are often the key in these patients.
2. Anterior Approach
The anterior approach, as described by Professor Belghiti , has been advocated for large right-sided tumours. This technique involves transection of the liver parenchyma to the IVC without mobilisation of the liver with the theoretical advantage of less tumour seeding. A prospective randomised controlled trial compared the anterior and conventional approach on 120 patients with large (>5 cm) HCCs. The anterior approach group had less blood transfusion requirements and a significantly longer overall survival (68.1 v 22.6 months; p = 0.006).
As in liver resection for other indications, there is no good evidence to indicate that a single method of parenchymal transection, application of fibrin sealants or intermittent inflow occlusion is beneficial in surgery for HCC. There is also no evidence to suggest that using special equipment for liver resection is of any benefit in decreasing the mortality, morbidity, or blood transfusion requirements. Surgeons should use techniques in which they have been trained and can demonstrate acceptable outcomes.
4. Laparoscopic Approach
Laparoscopic HCC resections are gaining popularity as the approach is more widely adopted across centres. It is important that patients for laparoscopic resection are selected based on the technical capabilities of the surgeon and centre, and the proper mentoring takes place during the learning curve. A summary of published metaanalyses concluded that the laparoscopic approach was associated with improved short-term outcomes (blood loss, complication rates and hospital length of stay) without compromising long-term oncological outcomes. It is worth noting that there are no randomised data; however a number of trials are in progress. Furthermore,their analysis suggested that the incidence of postoperative ascites and liver failure is decreased in the selected group of laparoscopic liver resections . A further metaanalysis of cirrhotic patients up to Child-Pugh B undergoing laparoscopic compared with open liver resection for HCC confirmed these perioperative benefits .
5. Robotic Approach
Although still very much in its infancy, the application of robotic surgery to HCC resection can theoretically yield similar advantages in short-term outcomes to the laparoscopic technique. The only comparative study between robotic and open liver resection for HCC included 183 patients undergoing robotic hepatectomy who were compared using propensity scoring with a cohort of 275 open resections. The robotic group required longer operating time (343 vs 220 min), shorter hospital stays (7.5 vs 10.1 days) and lower dosages of postoperative patient-controlled analgesia (350 vs 554 ng/kg). The 3-year disease-free survival of the robotic group was comparable with that of the open group (72.2% vs 58.0%; p = 0.062), as was the 3-year overall survival (92.6 vs 93.7%; p = 0.431). The associated financial costs of robotic surgery still pose a limitation to its adoption, and it is unclear if this approach is associated with any significant advantages over laparoscopic rather than open resection.
6. Associating Liver Partition with Portal Vein Ligation for Staged
ALPPS is still considered an experimental technique in which a first-stage procedure consisting of physical liver splitting and portal vein ligation is followed by a second stage of resection of the HCC and associated liver segments. The advantage seen in colorectal liver metastases is that of rapid hypertrophy for the FLR. There are only limited data describing outcomes of ALPPS for HCC; however an analysis of 35 patients in the international ALPPS registry showed an impressive FLR hypertrophy of 47% following the first stage of the procedure that was associated with a 31% perioperative mortality rate. The majority of these patients were in the intermediate-stage category of the BCLC algorithm. Further evaluation is required prior to routine use of ALPPS for HCC resection, and it is the view of the authors that ALPPS may be a procedure best reserved for carefully selected patients who have bilateral disease.
7. Combined Resection with RFA for Bilobar HCC
For patients with multiple or bilobar HCC in whom resection is contraindicated due to inadequate FLR, combined resection and radiofrequency ablation (RFA) may yield better results than alternative treatments. A single-centre study compared patients with bilobar liver HCCs who underwent resection (n = 89), combination of resection and RFA (n = 114) and TACE (n = 161). The results showed that 1-, 3- and 5-year survival was better in both resection and combined resection, and RFA groups compared with TACE and survival and disease-free survival were comparable between both surgical groups. They concluded that resection combined with RFA provided a chance for cure in patients with bilobar HCC, and provided liver function is preserved, aggressive treatment can improve prognosis.
In the healthy adult, the pancreas is a soft, retroperitoneal glandular organ, lying transversely and oblique and draped over the vertebral column at the level of L1–L2 vertebrae. The bulk or volume of the pancreas varies and increases during the first 2–3 decades of life but progressively atrophies with aging. The pancreas is divided into five parts: the head, neck, body, tail, and uncinate process. The neck, head, and uncinate process are encompassed by the C-loop of the duodenum, to the anatomic right of the midline, and are in intimate relationship with the superior mesenteric vessels medially. The body extends laterally to the anatomic left, posterior to the stomach, with the tail terminating in the splenic hilum.
The organ is surrounded by a thin capsule that is loosely attached to its surface. Most of the anterior surface of the pancreas is covered with peritoneum, except where it is crossed by the root of the transverse mesocolon, as well as where there is direct contact with the first part of the duodenum and the splenic hilum. The head of the pancreas is the thickest part of the gland. Anteriorly, it is related to the origin of the transverse mesocolon. Posteriorly, the head is related to the inferior vena cava (IVC), the right gonadal vein near its entrance into the vena cava, and the right crus of the diaphragm. The common bile duct runs either on the posterior surface of the pancreatic head or is embedded within the parenchyma of the gland.
The transitional zone between the head and the body of the pancreas is termed the neck. It is defined by its anatomic location anterior to the formation of the portal vein (usually by the confluence of the superior mesenteric and splenic veins).It is approximately 2 cm wide and usually the most anteriorly located portion of the pancreas. Anteriorly the neck is covered by peritoneum and is related to the pylorus superiorly. Its posterior aspect is grooved by the superior mesenteric vein (SMV) and the portal vein (PV).
The anterior body of the pancreas is covered by the peritoneal layer that constitutes part of the posterior wall of the lesser sac. Toward the inferior border of the pancreas, the peritoneal layer is reflected anteroinferiorly to form the superior leaf of the transverse mesocolon. The posterior surface of the body lies on the fusion fascia of Toldt in the retroperitoneum, the so-called bloodless plane of Treves. The posterior body is related to the abdominal aorta and the origin of the superior mesenteric artery (SMA), the left crus of the diaphragm, the left renal vein, the left kidney, and the left adrenal gland, from right to left.
The pancreas has important relationships to major blood vessels, of relevance to surgery of the pancreas. The splenic vein runs along the posterior surface of the gland in a groove of variable depth, sometimes almost entirely embedded within the pancreatic parenchyma. The celiac trunk and its branches emanate along the superior border of the body, with the common hepatic artery running to the right and the splenic artery to the left. The inferior border of the pancreas is crossed posteriorly by the inferior mesenteric vein (IMV), typically at its confluence with the splenic vein, and it serves as a useful landmark for identification of the former vessel on cross-sectional imaging.
The tail of the pancreas is the relatively mobile, left-most part of the pancreas that is confined between the layers of the splenorenal ligament together with the splenic artery and the origin of the splenic vein. It is 1.5–3.5 cm long in adults and may extend variably to the hilum of the spleen in 50% of cases and may extend posterior to vessels in the hilum. This makes the tail of the pancreas vulnerable to injury during splenectomy and needs to be visualized prior to ligating the splenic vessels. The uncinate process can be considered as a distinct part of the pancreas due to its different embryologic origin and its location extending posterior to the superior mesenteric vessels.
It extends in the plane between the superior mesenteric vessels anteriorly and the aorta posteriorly. Superiorly, it relates to the left renal vein. It lies immediately superior to the third part of the duodenum, such that tumors arising in the uncinate process can compress the former leading to duodenal obstruction. The main pancreatic duct of Wirsung begins at the tail of the pancreas and runs through the body roughly midway between the superior and inferior border. It receives multiple small ductules throughout its course that drain the pancreatic parenchyma, thus increasing progressively in diameter from 1 mm in the tail to 3 mm in the head. It deviates inferiorly and posteriorly in the head as it courses toward the main ampulla. The pancreatic duct and bile duct are usually separated by the transampullary septum before joining in a “Y” configuration within the duodenal wall.
The terminal part of the two ducts is surrounded by a complex circular arrangement of smooth muscle fibers known as the sphincter of Oddi. The sphincter of Oddi is anatomically distinct from the muscular layers of the duodenum, and it has a dual function: (a) to regulate flow of biliary and pancreatic secretions into the duodenal lumen and (b) to impede reflux of intestinal content into the pancreatobiliary ductal system. The accessory duct of Santorini runs superior and parallel to the duct of Wirsung. It drains part of the head of the pancreas into the minor duodenal papilla, roughly 1–2 cm proximal to the ampulla of Vater. The pattern of fusion of the main and accessory ducts is variable and can be entirely separate (pancreas divisum).
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.
Bariatric procedures differ in their ability to ameliorate T2DM, with intestinal bypass procedures generally associated with greater glycemic control and remission rates than purely restrictive procedures. There has been until now a paucity of data from RCTs comparing the efficacy of various bariatric procedures to treat diabetes. The recently published RCT by Schauer et al. also indicates superior efficacy of RYGB over sleeve gastrectomy in the treatment of diabetes in obese individuals. On the other hand, BPD produced greater remission of diabetes in morbidly obese patients compared to RYGB (95 % versus 75 %) in the RCT reported by Mingrone et al.
Sleeve Gastrectomy as Metabolic Surgery
Karamanakos et al. showed that LSG suppressed fasting and postprandial ghrelin levels and attributed this decrease in ghrelin to improved postoperative satiety and greater weight loss at 1year compared to LRYGB. The LRYGB group in this study had an initial decrease in ghrelin levels after surgery, but these levels returned to normal levels within 3 months. Lee et al. studied the treatment of patients with a low body mass index and type 2 diabetes mellitus between the two groups. LRYGB is reportedly more effective than LSG; they conclude that both procedures have strong hindgut effects after surgery, but LRYGB has a significant duodenal exclusion effect on cholecystokinin. The LSG group had lower acylated ghrelin and des-acylated ghrelin levels but greater concentrations of resistin than the LRYGB group. In addition to evaluations of ghrelin, there are now several small studies demonstrating that gastric emptying is increased after sleeve gastrectomy. The loss of a large reservoir in the gastric fundus and body and preservation of the antral pump provide a reasonable explanation for this finding. A secondary effect of earlier distal bowel stimulation with nutrients after meals due to increased gastric emptying time may be similar to the effects seen after gastric bypass.
Several mechanistic studies have demonstrated early and exaggerated postprandial peak levels of Peptide YY3–36 and GLP-1 after LSG. GLP-1 is an incretin that stimulates insulin production and releases from pancreatic islet cells, and the increased PYY3–36 results in satiety and reduced food intake. Karamanakos et al. have independently shown that the sleeve gastrectomy does have the effect of increasing the transit time of chyme despite an intact pylorus as measured by increased postprandial PYY levels.
Peterli et al. performed a randomized prospective trial with 13 LRYGB and 14 LSG patients to investigate the potential mechanism of LSG focusing on foregut and hindgut mechanisms. They found marked improvement in glucose homeostasis 1 week after surgery in both groups. This improvement was associated with early, exaggerated increases in GLP-1 secretion at 1 week, 3 months, and 1 year postoperatively in both groups. In addition to changes in GLP-1, PYY increased significantly and ghrelin was suppressed in both groups. It is unclear whether PYY has a direct effect on glucose homeostasis or if its effects are exhibited via appetite reduction and concomitant weight loss. Preoperatively, some patients had a blunted PYY and GLP-1 response suggesting some “resistance” to these gut hormones in obese patients. These findings suggest that the LSG should not be viewed merely as a restrictive procedure but also as a procedure that has neurohormonal and incretin effects.
Gastric Bypass versus Laparoscopic Sleeve Gastrectomy
Ramon et al. compared the effects of LRYGB and LSG on glucose metabolism and levels of gastrointestinal hormones such as ghrelin, leptin, GLP-1, peptide YY (PYY), and pancreatic polypeptide (PP) in morbid obese patients. This prospective, randomized study confirmed that the postprandial response of ghrelin, GLP-1, and PYY was maintained in patients undergoing LSG for 12 months after surgery and was similar to the LRYGB group results. A prospective, randomized study by Woelnerhanssen et al. compared the 1-year results of LRYGB and LSG for weight loss, metabolic control, and fasting adipokine levels. The authors confirmed a close association of specific adipokines with obesity and with the changes observed with weight loss after two different bariatric surgical procedures. The concentrations of circulating leptin levels decreased by almost 50 % as early as 1 week postoperatively and continued to decrease until 12 months postoperatively and adiponectin increased progressively. No differences were found between the LRYGB and LSG groups regarding adipokine changes.
How to choice a procedure?
The choice of procedure is an important determinant of outcome with a decreasing gradient of efficacy predicted from BPD, RYGB to SG and then LAGB. Other factors that have been positively correlated with diabetes remission are percentage of excess weight loss (% EWL), younger age, lower preop HbA1c, and shorter duration of diabetes (less than 5 years). Severity of diabetes, as judged by preop treatment modality, has also been noted to be a significant factor.
Schauer et al. have reported in their series of 191 obese diabetic patients (the majority of whom were on oral agents or insulin) a diabetes remission rate of 97 % in diet-controlled, 87 % in oral agent treated, and 62 % in insulin-treated subjects. This was also confirmed by a recent retrospective analysis of 505 morbidly obese diabetic patients who underwent RYGB. In this study, a more recent diagnosis of T2DM and the absence of preoperative insulin therapy were significant predictors of remission, independent of the percentage of EWL.
Dixon et al. have recently identified diabetes duration < 4 years, BMI > 35 kg/m2, and fasting c-peptide concentration > 2.9 ng/ mL as three clinically useful cutoffs and independent preoperative predictors of remission after analyzing the outcomes of 154 ethnic Chinese subjects after gastric bypass. C-peptide > 3 ng/mL has also previously been shown to be an important predictor of diabetes resolution after sleeve gastrectomy in non-morbidly obese diabetic subjects by Lee et al.
Sleeve gastrectomy (SG), or longitudinal gastric resection, consists in a resection of the greater curvature of the stomach. In bariatric surgery, it was introduced by Hess in 1988 and by Marceau in 1990 as a component of the biliopancreatic diversion with duodenal switch (BPD/DS). Resecting the greater curvature of the stomach was aimed at reducing the risk of ulcer at the level of the duodeno-ileal anastomosis of the BPD/ DS. In fact, for those authors, the amount of stomach removed was estimated to be roughly 60% and the restriction was moderate. With a view to reducing the mortality associated with laparoscopic BPS/DS in super-super-obese patients, Regan et al. described a 60-French (F) bougiecalibrated isolated sleeve gastrectomy (ISG) as a first step in a two-stage program of laparoscopic BPD/DS in 2000. Since then, primary ISG has gained popularity in a staged surgery program for high-risk patients. Although medium- to long-term results are not known, and some technical details are still being discussed, the good short-term results obtained regarding weight loss, as well as co-morbidity and the acceptable rate of complications, have broadened the indications for primary ISG and assured its place in the armamentarium of bariatric surgical procedures. In June 2007, a position statement on SG as a bariatric procedure was endorsed by the ASMBS, and in October 2007 the First International Consensus Summit for Sleeve Gastrectomy was held in New York City.
As expected, the operation is restrictive (satiety occurs very quickly). Indeed, with the current calibration of the sleeve, its volume is less than 10% of the entire stomach and its distensibility is 10 times less than that of the resected stomach and fundus. Nevertheless, after 6 months, patients can cope with a mug-sized meal (200 ml) of solid food. Even if the size of the meal is small, the volume of the remaining stomach is larger by far than after purely restrictive procedures (gastric banding, vertical banded gastroplasty). Melissas et al. demonstrated an accelerated gastric emptying of solid food into the duodenum and the intestine at 6 and 24 months, and this could explain some enterohormonal changes . In addition to these mechanical effects, SG has hormonal effects. This operation is “anorexigenic”; the patients feel little hunger and have only a mild interest in eating. Most of them could skip a meal each day for at least 1 year after surgery. The fundus is known to be the major source of ghrelin, an orexigenic hormone. It has been proved that the level of ghrelin is dramatically reduced after the currently performed SG with the entire fundus resected, and to a higher degree than with gastric banding or gastric bypass. Other hormonal changes have been noted, such as a rise in the level of fasting PYY or GLP1, a hormone that induces also a feeling of satiety. This latter point has yet to be assessed in human beings. These incretin modifications could play a role in the remarkable short-term effects observed on diabetes. Thus it appears that LSG is a multifactorial procedure with a mild restrictive aspect and a complex neurohormonal aspect.
Acute pancreatitis is a common intra-abdominal inflammatory condition of varied aetiology. The disease is mild in the vast majority of patients and has a favourable outcome. The acute severe form of the disease on the other hand is a lethal form with a high mortality and morbidity. A number of strategies have provided clinical benefit in severe acute pancreatitis (SAP). Of these, nutritional management is by far the most effective. SAP is associated with persistent end-organ failure, commonly respiratory, circulatory and renal. Treatment is targeted to support these organs. As of now there is no definitive therapy for acute pancreatitis. Patients are managed with fluids, analgesics, antibiotics and nutritional supplements besides adequately treating local complications such as pseudocyst and walled-off pancreatic necrosis by suitable interventional methods, be it endoscopic or percutaneous. The focus here is nutritional support in the management of SAP.
Which Form of Nutrition: Parenteral or Enteral?
This depends largely on the functional integrity of the stomach and small intestine. Patients of SAP often have poor gastric emptying and paralytic ileus, which is made worse with the use of narcotics. Moreover, local complications of pancreatitis (peripancreatic fluid collections) can have a pressure effect on the stomach and/or duodenum. As a result oral feeds may not be possible in these patients. Patients on ventilator support also cannot be given oral feeds.
Enteral feeding through the nasogastric or nasojejunal tubes is often not tolerated by patients because of discomfort. In addition, these tubes often get displaced or withdrawn. Reinsertion of the tubes, under endoscopic or radiological guidance, is cumbersome in such patients. All these factors favour parenteral feeding. The distinct advantage of enteral nutrition is that it prevents mucosal atrophy and transmigration of bacteria (an important causeof sepsis in SAP). Also, enteral feeding augments intestinal motility and is cheaper than parenteral preparations. Enteral nutrition improves motility in patients with paralytic ileus. The relative merits of these forms of nutritional therapy have been evaluated in a systematic review. Eight published randomized trials including a total of 348 patients were included. Enteral feeding was given through a nasojejunal tube and parenteral nutrition through a catheter placed in a central vein. Enteral nutrition was shown to reduce mortality, multi-organ failure, systemic infection and surgical intervention in comparison with parenteral nutrition. The length of hospital stay too was shown to be reduced. In view of these, enteral nutrition appears to be a better option while managing patients of SAP and has been recommended by the American College of Gastroenterology, American Gastroenterological Association and International Association of Pancreatology.
When should enteral feeding be started?
Patients with mild acute pancreatitis can usually be started on oral feeds in 2–3 days. Those with moderately severe acute pancreatitis can be started on oral feeding only after a variable period and hence should receive enteral nutritional support. Early enteral feeding has been shown to avoid end-organ failure in a large series of patients (1200).
Enteral feeding started within 48 h of onset of illness was associated with organ failure in 21% of patients as opposed to 81% when enteral feeding was started after 48 h. This benefit of early enteral feeding has also been shown in a recent meta-analysis. However, there was no benefit in mortality with early enteral feeding. In yet another randomized controlled trial, early enteral feeding (within 24 h) was compared with on-demand enteral feeding after 72 h.
The primary endpoint of this study was major infection or death. The study did not detect any significant difference in the primary endpoint in either group (early or on-demand feeding). However, it did show that patients receiving on-demand nutrition tolerated oral feeds without using a tube.
- Nasogastric or Nasojejunal
Should the feed be administered in the stomach through a nasogastric (NG) tube or in the jejunum through a nasojejunal (NJ) tube? Gastric feeding is thought to increase pain and aggravate pancreatitis due to food-induced pancreatic stimulation. In view of this, NJ feeding is practised. However, placement of a NJ tube is cumbersome and needs a skilled endoscopist or radiologist. It causes more inconvenience to patients. A nasogastric (NG) tube is thus an alternative. A number of studies have been published comparing NG and NJ feeding. The results of these studies can be summarized as follows: There was no difference in mortality. Feeds were equally tolerated in the two groups and NG feeding is simple. NG feed was not shown to increase pain and is thus as good as NJ feeding. A meta-analysis subsequently published showed no difference in mortality, hospital stay and infection rate between the two groups. Both forms of feeding were equally well tolerated. NJ feeding thus is not advised in the management of most patients with SAP. However, it still has a place when the patient has a high risk of aspiration. Also, patients on a ventilator and those not tolerating NG feed should be fed through NJ tube. The other issue concerning enteral feeding in SAP is the composition of the feed.
- Type of Formulation
Various commercially available formulations include (1) polymeric formulations comprising complex lipids, carbohydrates and proteins and (2) elemental formulations comprising simple amino acids, carbohydrates and free fatty acids. Other formulations used are glutamine-rich feeds and feeds with probiotics, fibres, etc. Immuno-nutrition using arginine, glutamine and polyunsaturated fatty acids has been evaluated in multiple studies and compared with standard feeding. A metaanalysis showed some benefit in mortality but not for prevention of infection, end-organ failure or inflammatory response. This benefit was not seen with the use of probiotics or fibre-based feeds. A systematic review did not show any benefit of immuno-nutrition or probiotics. It also showed that polymeric formulations are as well tolerated as oligomeric ones (elemental).
In the epoch of minimally invasive management of biliary and pancreatic disorders, endoscopic retrograde cholangiopancreatography (ERCP) combined with endoscopic sphincterotomy (ES) has become a prevalent procedure all over the world. Even though ES is a safe procedure, it carries a small but significant number of serious complications which include pancreatitis, bleeding, cholangitis and perforation. As per old literature, ERCP-related perforations were reported in 0.5–2.1% of sphincterotomies with a mortality rate of 16–18%. However, the improvement in the experience and skill of the endoscopy specialists combined with advancements in technology have reduced the incidence of perforation to <0.5% over the years. Sphincterotomy (56%) and guidewire manipulation (23%) are widespread causes of perforations related to endoscopic retrograde cholangiopancreatography (ERCP). There is a dearth of evidence-based strategies with respect to the proper management of ERCP perforations. While one set of investigators promote on-demand conservative and surgical management, based on a clinical course, the others support operative repair in all cases on account of the complications associated with the delayed operative intervention.
INDICATIONS OF SURGICAL MANAGEMENT
1. Large extravasation of contrast at the time of ERCP defined as incomplete dissipation of contrast after 1 min on follow-up plain film.
2. If there is only a small amount of contrast extravasation, where there is complete dissipation after 1 min of ERCP, on follow-up plain film, then a UGI with contrast injection on fluoroscopy is performed in 2–8 h. If this shows extravasation, we recommend surgical exploration.
3. Follow-up CT scan showing a collection due to perforation in the retroperitoneum or intraperitoneum.
4. Retained hardware unable to be removed by endoscopy along with perforation.
5. Massive subcutaneous emphysema.
6. Failure of conservative management.
A delay in diagnosis or in surgery will lead to death. The reason is that there is a massive autodigestion of body tissues which is due to a constant release of enzymes, and this eventually leads to sepsis. The principle of treatment by surgery is the same as endoscopic treatment. Any case that is suspected to have ERCP-induced perforation is kept nil by mouth, and the gastric contents are decompressed by Ryles tube and intravenous antibiotics.
This is done by diverting bile, enteric and pancreatic juices away from the site of perforation. However simple drainage will also cause the juices to flow through the perforation site and body cavities before draining out of the tubes. This could be avoided by diverting the juices through well-controlled different paths which could be done by the following procedures:
1. T-tube in CBD;
2. Placement of duodenostomy tube—lateral/end duodenostomy;
3. Duodenal diverticulization;
4. Pyloric exclusion;
5. Roux-en-Y duodenojejunostomy.
The disadvantage of using Roux-en-Y duodenojejunostomy is that if the edges are inflamed, then the sutures will not hold properly. However other procedures can be used even when the edges are inflamed. Even though duodenostomy appears to be simple, a part of gastric and duodenal contents pass across the perforation site.
Duodenal diverticulization involves three things: (1) tube to divert duodenal and pancreatic juice, (2) T-tube in CBD to divert bile and (3) distal
gastrectomy and Billroth II anastomosis to provide an alternate pathway for food and gastric juice, thereby preventing these from passing through the site of perforation. Although this procedure has been proved to be successful, it is less widely used due to its complex nature. Pyloric exclusion is a simpler form in which the pylorus is closed by purse string by long-standing absorbing sutures like PDS 2.0 instead of distal gastrectomy. Similar to duodenal diverticulization, T-tube drainage of the CBD and loop gastrojejunostomy are done. The duodenal perforation is closed over a duodenostomy tube.
Whenever there is collection which is localized to the retroperitoneum, retroperitoneal surgical approach can be carried out. Advantages of this procedure are (1) it permits gravitational drainage, (2) avoids septic complication of the peritoneal cavity, (3) directs retroperitoneal necrosectomy with post-operative washes and (4) avoids complex intra-abdominal surgeries. However the disadvantage of this procedure is that it can be used only for retroperitoneal-contained perforations.