Ninth Slide: Diagnostic Procedures

• Upper endoscopy can help visualize the gastric outlet and may provide a tissue diagnosis when the obstruction is intraluminal(внутрипросветная).

• The sodium chloride load test is a traditional clinical nonimaging study that may be helpful: The traditional sodium chloride load test is performed by infusing 750 cc of sodium chloride solution into the stomach via a nasogastric tube. A diagnosis of GOO is made if more than 400 cc remain in the stomach after 30 minutes.

• Barium upper gastrointestinal studies are very helpful because they can delineate the gastric silhouette (очертить желудочные контуры) and demonstrate the site of obstruction. An enlarged stomach with a narrowing of the pyloric channel or first portion of the duodenum helps differentiate GOO from gastroparesis.

• In the presence of PUD, endoscopic biopsy should be performed to rule out the presence of malignancy.

• In the case of peripancreatic malignancy, CT scan–guided biopsy may be helpful in establishing a preoperative diagnosis.

• Needle-guided biopsy also may be helpful in establishing the presence of metastatic disease. This knowledge may impact the magnitude of the procedure planned to alleviate the GOO.

Tenth Slide: Medical theraphy

Initial management of GOO should be the same regardless of the primary cause. After a diagnosis is made, patients should be admitted for hydration and correction of electrolyte abnormalities. Remembering that the metabolic alkalosis of GOO responds to the administration of chloride is important; therefore, sodium chloride solution should be the initial IV fluid of choice. Potassium deficits are corrected after repletion of volume status and after replacement of chloride. Nasogastric tube should be placed to decompress the stomach. Occasionally, a large tube is required because the undigested food blocks tubes with small diameters.

When acute PUD has been identified as a primary cause of gastric outlet obstruction (GOO), the treatment should be focused on the reduction of acid production. Histamine-2 (H2) blockers and proton pump inhibitors are the mainstay of treatment.

H pylori infection, when identified, must be treated according to current recommendations. Although most patients improve temporarily with treatment, scarring and fibrosis may worsen over time. Pneumatic balloon dilatation of a chronic, benign stricture can be performed via endoscopy. Patients who are candidates for balloon dilatation are likely to present with recurrent GOO. Published series using this technique report success rates of over 76% after multiple dilatations, although the rate of failure and recurrent obstruction is higher in patients treated with balloon dilatation who have not also been treated for H.pylori infection. Patients who are negative for H pylori do not respond favorably to balloon dilatation and should be considered for surgical treatment early in the process.

Further treatment is tailored to the underlying cause; this is where the distinction between benign and malignant disease becomes important.

Eleventh slide: Surgical Therapy: Benign diseases

• More than 75% of patients presenting with GOO eventually require surgical intervention. Surgical intervention usually provides definitive treatment of GOO, but it may result in its own comorbid (сопутствующие) consequences. Operative management should offer relief of obstruction and correction of the acid problem.

• The most common surgical procedures performed for GOO related to PUD are vagotomy and antrectomy, vagotomy and pyloroplasty, truncal vagotomy and gastrojejunostomy, pyloroplasty, and laparoscopic variants of the aforementioned procedures.

• Vagotomy and antrectomy with Billroth II reconstruction (gastrojejunostomy) seem to offer the best results. Vagotomy and pyloroplasty and pyloroplasty alone, although used with some success, can be technically difficult to perform due to scarring at the gastric outlet.

• Placement of a jejunostomy tube at the time of surgery should be considered. This provides temporary feeding access in already malnourished patients.

Image: A, Low subtotal gastrectomy; B, Billroth II anastomosis.

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Twelfth Slide: Surgical Therapy: Malignant diseases

Gastrojejunostomy remains the surgical treatment of choice for GOO secondary to malignancy. Although surgeons traditionally have preferred an antecolic anastomosis to prevent further obstruction by advancing tumor growth, a publication evaluating the retrocolic anastomosis in this setting challenges conventional wisdom(опровергает устоявшееся мнение). Results demonstrate that a retrocolic anastomosis may be associated with decreased incidences of delayed gastric emptying (6% vs 17%) and late GOO (2% vs 9%). Other groups have illustrated that partial stomach-partitioning gastrojejunostomy decreases the rates of delayed gastric emptying as compared with traditional gastrojejunostomy. Feeding jejunostomy should again be considered to combat malnutrition and slow recovery of gastric emptying.

• Internationally, studies are underway using laparoscopic gastrojejunostomy instead of the open procedure.

• Comparisons of laparoscopic gastrointestinal anastomosis versus the open procedure have revealed less morbidity and mortality, shorter hospital stays, fewer blood transfusions, and faster gastrointestinal transit recovery time.

Thirteenth slide: Surgical theraphy: Management of malignant diseases using metallic stents

Self-expandable metallic stents also have been used for the treatment of GOO in a malignant setting. Metallic stents have previously been used successfully to treat stenosis of such areas as the blood vessels, bile duct, esóphagus, and trachéa. With the development of newer stents and delivery systems, metallic stents may have a role in the nonsurgical treatment of gastroduodenal obstruction. Stents may allow the physician to avoid complicated surgical procedures. Currently, only the Wallstent has FDA approval for palliation(смягчение) in malignant gastroduodenal obstruction. Significant complications include the following: malposition, misdeployment, tumor ingrowth or overgrowth, migration, bleeding, and perforation.

Дата добавления: 2015-11-14