**4.5 Outcome**

Since its introduction, RYGB has helped patients with obesity to lose weight and control their comorbidities. Changes in eating habits, food preferences, and hormonal changes are some of the mechanisms explaining the procedure's efficacy [69]. Although less technically demanding procedures are available, RYGB is still considered the preferable procedure in some areas worldwide. Several reports demonstrated the efficacy of RYGB and its durability from a weight-loss standpoint over 10 years, with a total weight reduction of >25% in 61–71% of patients [70–72]. Despite that, weight regain can happen regardless of the type of weight-reducing surgery. Around 30% of patients with obesity subjected to LRYGB had weight regain, and the cause seems multifactorial, including patient-related causes (binge eating and sedentary lifestyle) and elapsed time since surgery [73, 74].

Different approaches can be employed when revising the RYGB after weight-regain or insufficient weight loss. These include modification of bowel length, resizing the gastric pouch, applying a restrictive band, or a combination of these interventions.

#### *4.5.1 Bowel length adjustments*

Shortening the common channel to augment the malabsorptive component of RYGB is an intuitive option. Since the configuration of RYGB results in a different type of bowel based on what they deliver, two options arise that leads to shortening the common channel. Firstly, is elongating the Roux limb that ends with shortening of the common channel, and the biliary limb is not affected [75]. Although excess weight loss was excellent with this technique, the risk of nutritional deficiency and protein malabsorption was frequent [76]. The second option is elongating the biliary limb by shortening the common channel [77, 78]. This results in less but effective weight loss, with less risk of malnutrition. There is no consensus on which procedure is optimal, and both procedures are adequate. However, what is essential is to avoid detrimental nutritional deficiency and malnutrition. This can be achieved by measuring the bowel length and ensuring adequate bowel length for nutrient absorption. A total alimentary limb (the sum of Roux limb and common channel) of more than four to five meters is adequate to avoid malnutrition [79].

#### *4.5.2 Resizing the gastric pouch only*

Focusing on enhancing the restrictive part of RYGB seems a safe and valid decision for the management of weight regain. The option includes either stapling the gastric pouch, the GJ anastomosis or both, to reduce the volume [80]. The other method is the plication of the gastric pouch under the guidance of a bougie [81]. It is crucial to evaluate the effect of remnant candy cane that might increase the volume of the oral intake. Resizing the gastric pouch not only augments the restrictive nature of RYGB but also reduces GERD by eliminating more of the acid-producing cells [82].

### *4.5.3 Application of restrictive band*

Bad eating habits can ensue after RYGB, probably due to the direct flow of food to the bowel. The size of the GJ anastomosis could be implicated in this phenomenon. Applying a band around the gastric pouch can prevent this hyperphagia through a simple restriction. Both types of band, that is, adjustable and nonadjustable, were examined and showed varying degrees of weight loss. In our opinion, band application seems less attractive compared to the remaining options because of the possible band complications (erosion and slippage) [83, 84].

Other available options include endoluminal revision, which has the lowest weight reduction compared to the other means [85, 86]. A combination of the options mentioned above is potentially valuable to maximize the chance of weight reduction. Careful patient selection and patient commitment are crucial to success.
