Gastric Sleeve vs. Gastric Bypass - Bariatric Surgical Procedures

Introduction:

Obesity surpasses undernourishment globally, with 1.5 billion affected. Bariatric surgery, notably Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy, offers significant and durable weight loss, reducing mortality and costs. However, up to 30 percent of patients may not achieve the desired weight loss. SG, despite its rising popularity, can lead to gastroesophageal reflux disease (GERD). Evaluating surgery outcomes is complex due to varied techniques, inconsistent follow-up, and a lack of standardized measures, hindering consensus on the optimal procedure.

What Is Meant by Gastric Sleeve?

Weight loss surgery has emerged as a safe and enduring treatment option for obesity, with techniques continually advancing and delivering improved results. Sleeve gastrectomy, a leading procedure in modern bariatric surgery, originated in 1990 as part of a two-stage operation for biliopancreatic diversion with duodenal switch (BPD-DS). The advent of laparoscopic sleeve gastrectomy in 1999 marked a significant milestone.

Initially intended for patients with super obesity (BMI greater than 60) to facilitate subsequent BPD-DS, sleeve gastrectomy showcased remarkable weight loss outcomes due to patient follow-ups. Consequently, in 2008, indications for laparoscopic sleeve gastrectomy were expanded. Compared to alternative weight-loss surgeries, sleeve gastrectomy stands out for its technical simplicity and lower morbidity, making it the predominant choice for weight-loss surgery.

What Is a Gastric Bypass?

Treatment options for obesity include both nonoperative management and bariatric surgery. Nonoperative approaches adopt a multimodal strategy, integrating dietary adjustments, enhanced physical activity, behavioral modifications, and pharmacotherapy. Despite widespread recommendations for dietary and exercise changes, their efficacy for the majority still needs to be improved. Bariatric surgeries, which can be malabsorptive, restrictive, or a combination of both, offer alternative interventions.

Standard procedures include Roux-en-Y gastric bypass, sleeve gastrectomy, and gastric banding. RYGB, introduced in 1966 by Mason, historically dominated bariatric procedures. However, the slow adoption of banding initially shifted trends, with banding surpassing bypass. Advancements in laparoscopic techniques across abdominal surgery have established laparoscopic bariatric procedures as the standard of care. The low morbidity and mortality associated with laparoscopic approaches have facilitated the introduction of day-case surgeries for bypass and gastrectomy procedures, highlighting bariatrics as a cost-effective intervention.

What Is the Procedure for Gastric Sleeve and Gastric Bypass Surgery?

Sleeve gastrectomy procedure:

1. Entrance and Setup: Trocar placement and insufflation of the abdomen.

2. Mobilization of the Greater Curvature: Dissection of the greater omentum division of vessels and mobilization of the angle of His.

3. Length From the Pylorus: Debate exists on the optimal distance from the pylorus to begin resection, typically ranging from two to six centimeters.

4. Identification and Repair of a Hiatal Hernia: If present, a hiatal hernia is reduced and repaired.

5. Posterior Mobilization: Separating the omentum from the greater curvature to access the lesser sac.

6. Bougie Placement: Insertion of a bougie under laparoscopic visualization to guide sleeve creation.

7. Creation of a Stapled Sleeve Gastrectomy: Sequential firing of an endoscopic stapler along the bougie, with attention to staple line integrity.

8. Reinforcement of Staple Line: Various techniques are employed to reduce staple line complications, with the current consensus favoring buttressing.

9. Endoscopy: Inspection of the staple line for integrity and hemostasis.

10. Closure: Fascial and skin closure at port sites.

Complications:

Early:

• Hemorrhage: Intraluminal or intraabdominal bleeding, managed surgically or endoscopically.

• Leak: Postoperative leaks may occur due to increased pressure on the staple line, often requiring prompt intervention.

Late:

• Stricture: Incidence up to four percent often presenting with dysphagia and requiring endoscopic or surgical management.
• Gastroesophageal Reflux: May develop or worsen, managed initially with proton pump inhibitors (PPIs) or, in severe cases, conversion to Roux-en-Y gastric bypass.
• Nutritional Deficiencies: Routine testing and supplementation are necessary to prevent deficiencies, though some nutrient deficiencies may still occur.
• Wernicke's Encephalopathy: Thiamine deficiency, characterized by altered mental status, oculomotor findings, and cerebellar impairment, requires immediate treatment with thiamine administration.

Gastric Bypass Surgery:

• Setup and Entrance: Patient is positioned supine, abdomen prepped, and draped. Trocars placed for laparoscopic access.
• Creation of the Roux-Limb: Omentum and transverse colon elevated to expose the ligament of Treitz. Jejunum divided approximately 40 to 50 centimeters distal to the duodenal-jejunal flexure. Roux-limb length determined, typically 75 to 150 centimeters, and marked.
• Jejunojejunal Anastomosis: Side-to-side anastomosis performed approximately 75 to 150 centimeters distal to the divided bowel, using stapling or suturing techniques. Mesenteric defects closed.
• Creation of the Gastric Pouch: Patient positioned steeply in reverse Trendelenburg. The liver retracted, his angle was divided, and the gastric pouch was created using stapling devices. Pouch size is targeted at 15 to 30 cc, with staple height optimized for stomach thickness.
• Gastrojejunal Anastomosis: Roux-limb brought to the gastric pouch, either retro colic retrogastric or ante-colic ante-gastric approach. Anastomosis was created using circular stapling, hand-sewn, or linear stapling techniques. Closure of mesenteric defects is required.
• Endoscopy: Inspection of anastomosis for bleeding and patency. Leak testing is performed if necessary.
• Closure: Fascial closure of more significant port sites and skin closure with sutures.

Considerations and Evidence:

• Roux-Limb Length: Recommended to be at least 75 cm to prevent bile reflux. Longer limbs (more than 150 cm) may benefit patients with a BMI of over 50.
• Gastric Pouch: Vertical orientation is desired to prevent distensible fundus inclusion. The volume is targeted at 15 to 30 mL, ensuring complete division from the remnant stomach.
• Roux-Limb Position: The ante-colic route avoids creating a defect in the transverse mesocolon, reducing internal hernia risk. The retrocolic approach increases hernia risk but may be necessary in certain cases.
• Gastrojejunal Anastomosis: Controversy exists over the impact of the technique on complications. Hand-sewn anastomosis may reduce leak and stricture rates but is more challenging.

What Are the Outcomes of Gastric Sleeve or Gastric Bypass?

Empirical evidence suggests that individuals with morbid obesity often experience a lower quality of life compared to those with an average weight. This includes psychological discomfort and impairment in various aspects of daily life, particularly in physical dimensions. Obese individuals commonly report poor health, increased unhealthy days due to physical or mental issues, and overall decreased well-being. However, the relationship between higher BMI and lower quality of life is not always straightforward.

For those seeking bariatric surgery, particularly those with morbid obesity, quality of life (QoL) scores tend to be lower, but bariatric procedures have been shown to improve QoL significantly. RYGB has favorable long-term clinical effectiveness regarding weight loss and resolution of comorbidities.

Weight loss is not the sole indicator of bariatric surgery success; QoL parameters and patient satisfaction are increasingly valued. Patient satisfaction post-bariatric surgery is associated with improved health, self-image, and social activity. Additionally, satisfaction increases with weight loss but decreases with unrealistic expectations.

Improvements in QoL after bariatric surgery have been observed as early as three months post-operation, with sustained effects reported over medium to long-term follow-ups. While weight loss is often associated with quality of life improvement, the relationship is complex and nonlinear. Factors such as fulfilling patient expectations and body image perception also play significant roles. Furthermore, QoL improvements may not necessarily correlate with weight loss alone but can also be influenced by the absence of comorbidities and patients’ ability to cope with expectations.

In bariatric surgery patients, high expectations and unrealistic goals can impact reported QoL. Emotional improvements post-surgery are often linked to better self-perception related to weight loss. Various factors, such as achieved BMI, body image, education level, and presence of psychiatric disorders, influence QoL outcomes in bariatric surgery patients. Post-surgery, improvements in gastrointestinal symptoms and food tolerance contribute to enhanced QoL. However, some patients may develop new symptoms, affecting overall satisfaction with eating and food choices and ultimately influencing weight loss outcomes.

Conclusion:

Both gastric sleeve and gastric bypass are effective bariatric surgeries with their own set of advantages and considerations. The gastric sleeve offers simplicity in technique and a lower risk of malabsorption, making it suitable for patients concerned about nutritional deficiencies. On the other hand, gastric bypass provides significant weight loss and can effectively address comorbidities like type 2 diabetes and GERD. The choice between the two procedures ultimately depends on individual patient factors, preferences, and the surgical team's expertise.