E. Strong (ed.). Gastric cancer. Principles and practice. Springer (2015)
Dumping syndrome can be classified on the basis of time (early versus late) and symptom type (?vasomotor versus gastrointestinal). Early dumping typically occurs within 30 min of eating, whereas late dumping occurs several hours after eating. Early dumping syndrome is likely the result of the rapid emptying of hyperosmolar food into the small bowel. Owing to the rapid hyperosmolar load into the bowel, fluid shifts into the bowel and causes a sympathetic response . Excessive gastrointestinal hormone secretion into the bowel and local peristaltic responses also play a role in this syndrome. Early dumping syndrome symptoms often include nausea, abdominal cramping, diarrhea, tachycardia, and possibly hypotension. Late dumping is often attributed to the aggressive insulin response to hyperglycemia induced by the rapid emptying of carbohydrate-rich food into the small bowel and occurs within 2–3 h after a meal. The insulin response leads to subsequent hypoglycemia, with symptoms such as fatigue, weakness, and diaphoresis. Vasomotor predominant dumping includes flushing, diaphoresis, palpitations, and tachycardia. Gastrointestinal predominant dumping includes symptoms of nausea, emesis, abdominal pain and cramping, and diarrhea.
As dumping is a relatively frequent postgastrectomy issue, diagnosis is made predominantly based on the presence of typical symptoms and inciting factors. In a large survey of over 1000 gastrectomy patients, 68% of patients had early dumping syndrome, and 38% had late dumping syndrome . Although criteria for dumping syndrome have been developed on the basis of a 50-g glucose provocative test, subjective symptoms remain the mainstay of diagnosis . Diagnosis can also be confirmed with improvement from dietary modifications. Patients with early dumping syndrome are susceptible to developing late dumping syndrome. Patients who lose more weight after surgery are also prone to dumping syndrome .
Fig. 17.1. Computed tomography (CT) image of a patient with duodenal stump leakage after subtotal gastrectomy. Red arrow indicates fluid and air at duodenal stump staple line
Dietary management is the primary treatment modality for dumping syndrome and is often successful. Patients should avoid foods with high levels of simple carbohydrates (sugar) and attempt to eat small, frequent meals with foods high in fiber and protein. Patients should eat 6–8 meals per day and restrict fluids while eating. Vasomotor-predominant dumping symptoms can be improved if the patient rests in the supine position for 20–30 min after eating. Severe dumping syndrome refractory to standard dietary changes may be improved with octreotide [19, 20]. Long-acting repeatable (LAR) intramuscular octreotide injection appears to be as effective at improving postoperative dumping as short-acting subcutaneous octreotide. The LAR form of octreotide has the obvious benefit of monthly injection compared with three injections per day of the short-acting formulation. Comparison studies have shown that the LAR form of octreotide improves quality of life scores . Limitations to octreotide therapy include an apparent tolerance to the therapeutic effect and long-term side effects that include gallstones, diarrhea, and steatorrhea [21, 22].
With the decrease in surgery for peptic ulcer disease, the high rates of success in treating dumping syndrome with medical management, and the natural history of gastric cancer, surgery is an extremely rare treatment for dumping syndrome and is primarily of historical interest. In addition, there is no clear consensus on the optimal surgical intervention for dumping syndrome. The most commonly suggested surgical treatment is to create a Roux-en-Y gastrojejunostomy. In patients with a previous Billroth II loop gastrojejunostomy, the afferent jejunal limb is transected and anastomosed 60 cm distal to the gastrojejunostomy. In patients with a previous Billroth I gastroduodenostomy, the duodenum is transected, additional gastrectomy is performed, and a Roux-en-Y reconstruction is performed. Another reported option is the reversed jejunal interposition graft, described as the interposition of an antiperistaltic jejunal segment between the stomach and duodenum. However, most reports of this operation are old enough to question whether it should still be considered an option .
Afferent limb syndrome
Afferent limb syndrome is a partial or complete obstruction of the small bowel involving the afferent limb and anastomotic site after loop gastrojejunostomy. Creation of a loop gastrojejunostomy involves an afferent limb of proximal jejunum that transports bile and pancreatic fluid to the stomach. The efferent limb is the distal limb of the anastomosis and transports bile, pancreatic fluid, and gastric contents distally into the jejunum. Obstruction of the afferent limb can be secondary to adhesions, internal hernia formation, stenosis owing to cancer recurrence or ulceration, and intussusception. There is some controversy as to predisposing factors, but most authors report that afferent limb obstructions are more common in patients with longer afferent limbs and with an anastomosis of the afferent limb to the lesser curvature of the stomach . Retrocolic placement is occasionally mentioned as a preventative procedure for afferent limb syndrome secondary to adhesions, but this procedure does increase the risk of an internal hernia through the mesocolic defect.
Classical symptoms of afferent limb syndrome include intermittent epigastric/right upper quadrant pain relieved by bilious emesis. The abdominal pain is often described as cramping or colicky, and the bilious emesis can be forceful or even projectile. Afferent limb syndrome in the immediate postoperative period must be differentiated from postoperative gastroparesis or ileus and must be treated promptly to prevent a duodenal stump leak. The more chronic form of afferent limb syndrome can have a presentation similar to bile reflux gastritis. Most afferent limb syndromes are diagnosed with CT imaging, which not only documents the site of obstruction but also reveals potential malignant obstructions or metastatic disease in patients with a history of cancer. Figure 17.2a, b) demonstrate CT images of a patient with afferent limb syndrome secondary to recurrence of gastric cancer at the gastrojejunostomy performed with subtotal gastrectomy. Historical reports often mention that hepatobiliary iminodiacetic acid (HIDA) scans of patients with afferent limb syndrome follow the flow of radiolabeled bile into the obstructed afferent limb with minimal or no transit into the remaining gastrointestinal tract. Endoscopy can be helpful to determine the etiology of obstruction such as gastric remnant-related malignancy, cancer recurrence, and marginal ulceration or stenosis.
Fig. 17.2. a) Computed tomography (CT) image of a patient with afferent limb syndrome due to recurrence of gastric cancer at gastrojejunostomy staple line (red arrow). b) CT image of dilated duodenum in a patient with afferent limb syndrome
In the immediate postoperative setting, afferent limb obstruction can require emergency surgery and should be suspected in situations of duodenal stump leakage. In nonemergent situations, medical management can include a trial of nasogastric tube decompression and hydration, although a nasogastric tube may not decompress the afferent limb adequately. Stent placement or endoscopy with dilation also is an option for nonsurgical management.
There are two main options for surgical correction of afferent limb syndrome; revision of the existing gastrojejunostomy is usually not one of these options. First, and simplest, is a jejunojejunostomy between the afferent and efferent limbs, sometimes referred to as a Braun enteroenterostomy. This approach requires minimal dissection and no bowel transection and should be an option in most patients. Although creating a shorter afferent limb during the initial surgery can prevent afferent limb syndrome, a shorter limb can also prevent enteroenterostomy as an option for treating this postoperative complication. The second option for treating afferent limb syndrome is converting the original surgery into a traditional Roux-en-Y gastrojejunostomy. This approach also involves leaving the existing gastrojejunostomy in place, transecting the afferent limb close to the stomach, and creating a 60-cm Roux limb with a jejunojejunostomy between the transected afferent limb and the efferent limb 60-cm distal to the gastrojejunostomy. If the patient has any history of bile reflux gastritis, the Roux-en-Y gastrojejunostomy should be considered.
Efferent limb syndrome
Efferent limb syndrome refers to a mechanical obstruction at or distal to the Billroth II gastrojejunostomy. Symptoms include traditional symptoms of obstruction such as nausea, emesis, and distention but can include bilious emesis similar to delayed gastric emptying, bile reflux gastritis, and afferent limb syndrome. Adhesions or stenosis secondary to marginal ulceration are benign causes of obstruction, whereas local recurrence or carcinomatosis can represent malignant causes.
To differentiate efferent limb syndrome from other causes of bilious emesis, physicians should use CT scans or esophagogastroduodenoscopy. A HIDA scan can be helpful in more chronic situations to differentiate efferent limb syndrome from bile reflux gastritis. A gastric emptying scan or upper gastrointestinal fluoroscopy may be required to differentiate efferent limb syndrome from delayed gastric emptying.
Surgery is the preferred treatment of efferent limb syndrome with benign causes of stenosis or obstruction. For malignant etiologies, treatment should balance estimated prognosis, perioperative risk, extent of surgery, and oncologic treatment options. Options include stent placement, venting gastrostomy tubes, and antisecretory medications such as octreotide.
As in afferent limb syndrome, revision of an anastomotic stricture is rarely an option in efferent limb syndrome. In a patient with favorable anatomy after the initial gastrojejunostomy and with operative risk favoring less extensive surgery, a gastrointestinal anastomosis stapler can be used to extend the anastomotic stricture either proximally or distally. The gastrostomy and enterotomy from this revised anastomosis can then be closed with interrupted sutures or with a thoracoabdominal stapler. Most patients, especially those with a high suspicion for bile reflux gastritis, are treated with resection of the anastomosis and a Roux-en-Y reconstruction. Patients with delayed gastric emptying can be considered for resection of the anastomosis with new Billroth II reconstruction and enteroenterostomy downstream to prevent bile reflux gastritis.
Roux stasis syndrome
Roux stasis syndrome is a disorder of gastric remnant or upper intestinal motility that manifests with symptoms (most often postprandial) of nausea, emesis, and abdominal pain. The syndrome is attributed to the effects of vagotomy and proximal small bowel transection. Small bowel transection disrupts the cyclical electrical charges and action potentials that spread distally along the small bowel and coordinate peristaltic muscle contractions. Patients who underwent a Roux-en-Y gastrojejunostomy had consistently slower transit than did control subjects; however, these findings do not correlate to symptoms . Symptoms of upper gastrointestinal dysmotility after gastric resection and Roux-en-Y gastrojejunostomy are multifactorial, and few recent studies have investigated diagnosis and treatment of this complication. The study of this syndrome was more relevant in the past when surgery was mainly performed to treat peptic ulcer disease. Roux stasis syndrome is infrequently encountered after gastric cancer surgery and almost never requires operative intervention.
There are early (within 90 days of surgery) and late variants of Roux stasis syndrome. Suspicion of Roux stasis syndrome should be maintained in patients with postprandial symptoms of pain, nausea, and emesis. As in other postgastrectomy syndromes, the diagnosis of Roux stasis syndrome is one of exclusion after ruling out mechanical forms of obstruction, infections, and technical complications.
- Must be differentiated from postoperative gastroparesis or early postoperative small bowel obstruction. CT imaging is the primary modality to rule out postoperative mechanical obstruction, but upper gastrointestinal fluoroscopy or endoscopy can also be useful. The diagnosis is often made in the setting of a normal CT scan in patients with symptoms of gastroparesis that persist longer than the typical clinical scenario of postoperative gastroparesis or ileus.
- Late. Differential diagnosis of late Roux stasis syndrome includes anastomotic stricture, adhesive bowel obstruction, internal hernia, and malignant bowel obstruction. CT imaging, fluoroscopy, endoscopy, and nuclear medicine gastric emptying studies may be helpful in diagnosing late Roux stasis syndrome.
There are few good surgical options for this syndrome, and therefore medical management is the main treatment modality. A thorough history can help to elicit factors or meals that exacerbate postprandial symptoms. Dietary modification with small, frequent meals is often helpful. Liquids will typically empty better than solids and may improve symptoms. Nutritional liquid supplements between meals are often crucial in providing enough calories with small meals. Metoclopramide and erythromycin, although not good long-term medications, can be helpful in the short term in breaking the cycle of the patient’s symptoms.
Surgical intervention in patients with Roux stasis syndrome often focuses on two main procedures: (1) resection of the remnant stomach with neartotal or total gastrectomy, and (2) feeding tube placement.
Bile reflux gastritis
Patients who undergo pyloroplasty, gastroduodenostomy (Billroth I), and loop gastrojejunostomy (Billroth II) are predisposed to bile reflux gastritis. Bile reflux gastritis, similar to other postgastrectomy syndromes, is becoming as infrequent as surgery for peptic ulcer disease owing to the accumulating evidence for the superiority of Roux-en-Y reconstruction over other means of reconstruction after gastrectomy for gastric cancer. In a study using an intragastric bile monitor and endoscopic evaluation, surgeons from Japan have demonstrated less bile reflux and remnant gastritis in patients who underwent Roux-enY reconstruction than in those who underwent Billroth I and II reconstruction . The longterm results of a prospective randomized trial of Billroth II and Roux-en-Y reconstruction after gastrectomy for peptic ulcer disease showed improved patient-reported outcomes, improved endoscopic findings, and less histologic evidence of gastritis in patients who underwent Roux-en-Y gastrojejunostomy .
Bile reflux gastritis is most commonly diagnosed by the findings of abdominal pain, nausea, bilious emesis, and bile and inflammation in the stomach. Most, if not all, patients who have undergone a distal gastrectomy with Billroth I or II reconstruction will have bile and inflammation in the stomach, which makes diagnosing bile reflux gastritis challenging. The indications for surgical intervention in this disease should take into account other etiologies as a cause of the patient’s symptoms. Other etiologies to consider in the differential diagnosis are nonbilious reflux, gastroparesis, marginal ulceration, peptic ulcer disease, afferent/efferent limb syndromes, adhesive bowel obstruction, malignant bowel obstruction, and chronic abdominal pain owing to previous surgery.
Considering the broad differential diagnosis, the likely multifactorial etiology of the patient’s symptoms, and the modest outcomes associated with surgical intervention, physicians should perform an extensive diagnostic workup of patients with possible bile reflux gastritis and should approach this diagnosis with a “diagnosis of exclusion” mentality. Endoscopy is essential to document bile reflux and gastritis. A CT scan of the chest, abdomen, and pelvis should be considered in patients with a history of malignancy to rule out metastatic disease and recurrence as a cause of symptoms before performing an extensive operation. A HIDA scan can also be helpful to document pooling of bile within the stomach. An upper gastrointestinal series is appropriate to evaluate not only postoperative anatomy and function but also obstruction. Similarly, a gastric emptying scan is crucial to rule out gastroparesis, which can be worsened by further operation.
Cholestyramine, a bile acid-binding resin, is generally ineffective for treating bile reflux gastritis owing to this medication’s rapid transport through the stomach. In one study, patients treated with cholestyramine plus alginates to help reduce transit out of the stomach had no difference in symptoms, endoscopic findings, or histologic findings than did the placebo group . Sucralfate, a medication that coats the surface of the stomach to protect against acid and bile salts, may last for up to 6 h with minimal side effects. In a small placebo-controlled trial of 23 patients, after 6 weeks of treatment, the sucralfate-treated group demonstrated improvement in histologic inflammation but no improvement in symptoms . Ursodeoxycholic acid’s mechanism of action is to reduce the cholesterol content of bile and the reabsorption of cholesterol by the intestines. One small study of 12 patients reported that patients treated with ursodiol had fewer symptoms associated with bile reflux gastritis than did the placebo group .
Definitive treatment of bile reflux gastritis usually requires surgery, although success varied from 47 to 91% in studies from an era when surgery was more frequently performed to treat peptic ulcer disease [31–34]. Although most patients with gastric cancer who experience bile reflux gastritis will have had a Billroth II gastrojejunostomy, surgical treatment is similar after Billroth I gastroduodenostomy, and Roux-en-Y gastrojejunostomy is the most common recommendation.
For patients with Billroth I anatomy, the duodenum is transected distal to the anastomosis, and the stomach is transected. The remnant stomach volume depends on the presence of gastroparesis; patients with gastroparesis will benefit from subtotal gastrectomy with less stomach remnant. For patients with Billroth II anatomy, the two main options include Braun enteroenterostomy and Roux-en-Y gastrojejunostomy. For Braun enteroenterostomy, the anastomosis is performed between the afferent and efferent limbs of the Billroth II gastrojejunostomy. The efferent limb of the anastomosis is typically anastomosed between 45 and 60 cm distal to the gastrojejunostomy to prevent continued bile reflux gastritis. For conversion to a Roux-en-Y gastrojejunostomy in a patient who requires additional gastrectomy, the afferent and efferent limbs are transected close to the stomach, and a 60-cm Roux limb is created. In patients not requiring additional gastrectomy, the afferent limb is divided close to the stomach and anastomosed to the efferent limb to create a 60-cm Roux limb.
Postvagotomy diarrhea is a syndrome of unclear etiology that occurs in a minority of patients after truncal vagotomy. Although gastric resection is not required for postvagotomy diarrhea, many patients have concomitant gastric procedures, and this disorder is often classified with other postgastrectomy syndromes. Although the pathophysiology of this disorder has not been clearly identified, the syndrome is likely the result of alteration in pacemaker function, intestinal motility, hypoacidity, malabsorption, bacterial overgrowth, or a combination of these factors.
Another possible diagnosis often considered in patients with diarrhea after gastrectomy and vagotomy is dumping syndrome. When compared with dumping syndrome, postvagotomy diarrhea often involves more frequent bowel movements, no relation to oral intake, and often occurs consistently throughout the day and night. Rarely, postvagotomy diarrhea can result in fatigue, hypovolemia, and malnutrition.
Dietary modification is an essential component of medical management and attempts should be made to identify causative foods. Commonly reported inciting foods are caffeine and milk products. Dietary fiber supplements may help to improve diarrhea. Medical management includes loperamide, diphenoxylate, and possibly antibiotics to rule out bacterial overgrowth. A trial of octreotide may also be warranted. Patience during treatment is required for the patient and physician, as there are few surgical options and symptoms may take several months to resolve.
Surgical intervention is primarily of historical interest and is seldom required for postvagotomy diarrhea. The most reported procedure is a 10-cm reversed jejunal segment in the distal jejunum. This antiperistaltic procedure mechanically slows transit time and may facilitate better absorption.
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