Long-term risks of complications and nutritional deficiencies from bariatric surgery

Anastomotic leakage after LRYGB or BPD-DS surgery can lead to very serious consequences, with approximately 30% of anastomotic leakage cases being fatal. Its clinical manifestations may be latent or delayed.

The probability of anastomotic leakage is comparable between LRYGB and BPD-DS, not exceeding 5%. Experiences by Wittgrove and Clark et al. suggest that the incidence of anastomotic leakage decreases with increasing surgeon experience. Furthermore, the incidence of gastric perforation after LAGB is 0.5%–0.8%.

Wound infection is relatively less common in laparoscopic surgery than in open surgery. The wound infection rate is higher after laparoscopic biopsy (BPD), with 3 out of 18 patients in one study developing wound infections.

Unlike wound infections from open surgery, wound infections from laparoscopic surgery are more easily controlled through local wound management and usually do not lead to serious consequences. The wound infection rate after LRYGB and LAGB is low, generally not exceeding 9%.

In Chapman's review of LAGB, the postoperative wound infection rate was only 0.28%, while in Podnos et al.'s review of LRYGB, the postoperative wound infection rate was reported to be 2.98%.

The lower incidence of wound infection in LAGB may be attributed to the fact that the gastrointestinal tract is not cut during the procedure, which is one of the main advantages of LAGB.

Fortunately, deep vein thrombosis and pulmonary embolism were relatively rare complications in all studies. Pulmonary embolism after bariatric surgery is a leading cause of postoperative death. Two studies of laparoscopic BPD-DS reported an incidence rate of 0.5%–2.5%.

In a study of LRYGB patients with over 100 patients, the incidence of postoperative DVT was 0%–0.3%, while the incidence of PE was 0.3%–1.1%. O'Brien reported very low incidences of both postoperative DVT and PE in over 700 LAGB patients.

The low incidence of DVT/PE after LAGB surgery may be related to patient selection and shorter operation time. All patients in these reports adhered to strict DVT and PE prevention measures, and the statistically reported DVT/PE complications all presented with significant clinical symptoms.

**Long-term complications**

The early complication rate of LAGB surgery is very low, mainly because it does not involve gastrointestinal anastomosis and related fistulas and bleeding. However, complications can occur in the late postoperative period for all three surgical methods, and the type of complication is related to the surgical method.

Patients with LAGB typically do not experience anastomosis-related or nutrition-related complications, but due to factors such as bandages, infusion tubing, and pumps, they may require repeat surgery several months to several years post-surgery. There are currently no reports of long-term follow-up of laparoscopic bariatric surgery exceeding 10 years.

Overall, the long-term effects of placing a silicone bandage on the basal surface of the stomach are still unknown. Long-term corrosion and esophageal dilation may be concerns, but current 6-year follow-up results indicate that these are not major issues following gastric bandaging.

Some complications that may occur in the long term with RYGB and BPD-DS surgery performed via open surgery can also occur with laparoscopic surgery, but the incidence of incisional hernia is greatly reduced with laparoscopic surgery.

The reporting methods for long-term complications vary across studies, and there is currently no clear distinction between major and minor complications. Schauer et al. reported a long-term complication rate of 47% after LRGBP surgery.

This includes major and minor complications such as anastomotic stricture or ulceration, gastric fistula, DVT, hernia, anemia, hypokalemia, and other side effects such as intractable nausea or vomiting, as well as symptomatic cholangitis.

In some large studies, the incidence of long-term anastomotic stenosis after LRGBP was 2%–11%, but the incidence of anastomotic stenosis was 26% when using a circular stapler, especially a 21 mm circular stapler for gastrojejunostomy.

The incidence of anastomotic stenosis after laparoscopic BPD-DS surgery ranges from 1.7% to 7.6%, which is acceptable and can be treated endoscopically in most cases.

Although studies on open surgery have shown that the incidence of marginal ulceration as a complication is 3% to 10%, there is currently no data on the incidence of marginal ulceration in laparoscopic BPD-DS surgery.

Intestinal obstruction can occur through the Peterson space on the transverse mesocolon of the Roux loop in the posterior colon or at the mesenteric gap during enteroenterostomy. The incidence in RYGB can be as high as 10%.

Data on postoperative bowel obstruction after laparoscopic BPD-DS is limited. In Rabkin's study of 345 patients undergoing hand-assisted laparoscopy, the incidence of postoperative bowel obstruction was 1.5%.

The reoperation rate for various procedures is relatively constant, but LAGB typically has a higher reoperation rate due to strap slippage or problems with the infusion pump. LAGB has some unique long-term complications, including strap displacement, detachment, strap corrosion of the stomach, gastric outlet obstruction, malfunction of the infusion tubing and pump, or infection. Occasionally, about 3.1% of patients cannot tolerate the restriction on the stomach caused by the strap and request its removal.

Overall, the incidence of early and long-term complications after LAGB is low. The incidence of bandage-related complications, including bandage displacement or slippage, is similar to that of some complications specific to the LRYGB procedure itself, including anastomotic leakage, stenosis, and intestinal obstruction.

The postoperative complication rate of LRYGB is between that of LAGB and BPD-DS, and is generally acceptable. Currently, there is limited literature reporting on long-term complications of laparoscopic BPD-DS. Compared with open BPD-DS, although it has very good and lasting weight loss, the complication rate is also high.

Malnutrition is unavoidable in surgeries that require bypassing any segment of the intestine. However, surgeries that restrict food intake, such as LAGB, typically do not cause nutritional deficiencies.

Surgeries that cause malabsorption, such as BPD-DS and distal RYGB, have a higher incidence of nutritional problems, including protein malnutrition. Vitamin and micronutrient deficiencies can be corrected with oral supplements.

Patients undergoing these surgeries should be aware that they will need to take nutritional supplements for life, and if they cannot follow this, they are not suitable for such surgeries.

**mortality rate**

In Buchwald's meta-analysis, the 30-day perioperative mortality rates were: BPD 1.1%, RYGB 0.5%, and food restriction surgery 0.1%. The range of mortality rates associated with some large-sample laparoscopic bariatric surgeries is shown in Table 24.1.

Among all surgical procedures, laparoscopic breech-amplified dilation and prolapse (BPD) had the highest mortality rate, although only 40 cases were performed, with one patient dying, resulting in a mortality rate of 2.5%. The higher mortality rate of BPD compared to the other two procedures is generally accepted, and this conclusion is supported by meta-analysis.

This may be related to patient selection. Patients undergoing BPD-DS surgery typically have a higher BMI than those undergoing LRYGB or LAGB surgery, and increased BMI is a predictor of perioperative complications and mortality.

(Translated by Ji Gang)