Long-Term Results of Bariatric Restrictive Procedures: A Prospective Study

Morbid obesity and its related comorbidities is a worldwide epidemic. Surgery is, in contrast to conventional treatment modalities, the only treatment with a proven long-lasting effect on weight and comorbidities and has a positive effect on the quality of life [19, 20]. Weight loss more than 5 years after VBG varies in the literature from 30% to 59% EWL [13, 14, 21] while, after LAGB, it varies from 56% to 62% EWL ([13, 14, 22]. The long-term results of O'Brien et al. show that, 10 years after gastric banding, it is still successful, and weight loss is comparable with gastric bypass (59% and 52% EWL, respectively) [23]. Most studies show a rapid weight loss after VBG with a weight regain after 2 years while patients with LAGB tend to lose weight more slowly but for a prolonged period. Our study results are consistent with the literature with 73% and 55% EWL after 2 years and 69% and 54% EWL after 7 years for VBG and LAGB, respectively. Weight loss was not significantly different between 2 and 7 years within the groups. Although weight loss was significantly more after VBG compared with LAGB, it is important to notice that 60% of patients in the VBG group no longer had the VBG configuration but were converted to RYGB because of complications. On the other hand, weight loss was the same after 7 years for patients in the VBG group with or without conversion to RYGB (both EWL of 69%). In terms of weight loss, successful bariatric surgery is defined as the maintenance of EWL of at least 50%. In our patient group, this applies to 79% of VBG patients (converted and non-converted) and 60% of LAGB patients.

The decrease in obesity-related comorbidities after bariatric surgery is well-documented and depends on the weight loss and the type of surgery [20, 24‐26]. Our study confirms this once again, but interestingly, an increase in T2DM was observed 7 years after LAGB while it was almost non-existent after 2 years. A clear explanation for this increase from one to five patients was not found. Weight loss in these five patients was EWL 44% and for the total group of LAGB patients 54% (ns). They also did not experience a rapid weight gain during the final period of follow-up. Furthermore, three patients in this diabetic group did not have any complications while two patients had a band slippage and underwent refixation. There is no literature available describing a possible increase in diabetes many years after LAGB. Possibly, a combination of factors could be responsible for this phenomenon. The 10% difference in weight loss could be important because a resolution of T2DM is possible after only 10% weight loss [27, 28]. Furthermore, the aging of the study population during follow-up could be a factor in the development of T2DM.

A wide range of laboratory measurements was investigated 7 years after surgery including hemoglobin, urea, creatinin, ASAT, ALAT, albumin, total protein, cholesterol, triglycerides, HDL, and LDL. There were no significant differences between the groups and except high-density lipoprotein in the VBG and converted RYGB patients, all values were within normal ranges. The values of minerals and vitamins (iron, zinc, vitamin B1, B6, B12, and folic acid) are especially of interest. In all groups, including the converted RYGB patients, all levels were within the normal range implying no deficiencies were present. In the literature, comparison between restrictive and more malabsorptive procedures shows that deficiencies are much less common after purely restrictive procedures because the gastrointestinal tract remains intact and absorption is normal [29, 30]. This is confirmed in several reports except that low levels of folic acid are frequently observed caused by a difference in eating habits after surgery (less wholemeal bread, vegetables, and fruit) [31, 32]. This is considered the most important reason to recommend vitamin supplementation after restrictive surgery. However, in the present study, the postoperative levels of folic acid were normal irrespective of vitamin supplement usage. The supplement use was low in both groups but significantly higher in the LAGB group (55%) compared with the VBG/RYGB group (32%). Continued vitamin use is probably associated with regular follow-up, and this tends to be higher after LAGB because of visits before and after insufflations. On the other hand, vitamin B12 injections (every 3 months) and iron supplements were used more frequently after VBG and RYGB than after LAGB (29% versus 21% and 13% versus 6% of patients, respectively). The latter can be explained by the 60% conversion rate to RYGB in the VBG group. The deficiency of vitamin B12 and iron is well-known after RYGB because of the bypassed stomach and proximal intestine [33‐35], and therefore, vitamin monitoring and supplementation is mandatory after RYGB. In our study group, a pattern in vitamin supplement usage and vitamin levels was not apparent. Patients without any supplements also had normal vitamin levels, and this issue has been discussed in the literature [36]. It is mostly explained by medication adherence which is, in case of bariatric surgery, below 50% and deteriorates during follow-up [30, 37]. No randomized trials on this subject are published to provide a definitive answer if supplements are needed after purely restrictive procedures, and therefore, it is still common practice to prescribe vitamin supplements to all bariatric patients. Although our results are not consistent, based on the available literature and possible consequences of deficiencies, continuation of this policy seems justified.

Revisional surgery is often necessary after VBG because of stoma stenosis, pouch enlargement, or stapler line dehiscence. Percentages in the literature range from 10% to 50% and are strongly associated with the completeness and duration of follow-up [38‐42]. Also, developments in VBG techniques may possibly lead to better results with a lower re-operation rate, e.g., the Mason McLean operation with partition of the stomach instead of only stapling. However, no long-term results of this procedure are described in the literature, so a comparison with standard VBG or LAGB is not possible. In the present study, the mean time between the primary operation and the re-operation was 2 years with a range from 6 months to 7 years. Therefore, in order to present reliable re-operation rates after VBG, a minimum follow-up period of 3 years is necessary. Balsiger et al. described a re-operation rate of 19% 10 years after VBG [21]. Comparable results were found by van de Weijgert et al. with a re-operation rate of 18% after a mean period of 7.2 years [43]. Studies by van Gemert et al. and MacLean et al. reported higher rates (31% and 36%, respectively) after 52 months and 2 to 5 years of follow-up [39, 41]. Finally, the prospective study by Miller et al. (follow-up of 92 months) is most comparative with our results with a re-operation rate after VBG of 49.7% [14]. Purely technical failure after VBG occurred in 65% of our patients, and in all cases, conversion to RYGB was performed. Conversion from VBG to RYGB has been described in literature with positive results. Sugerman et al. reported on 53 patients where EWL increased from 36% to 67% after the conversion [44]. The patient group of Cordera et al. showed a decrease in BMI of 46 to 35 kg/m² after conversion [45]. Kfoury et al. performed a distal RYGB in 45 patients after failed VBG. Results after a follow-up period of at least 2 years were available for 29 patients, and % EWL was 74% in this group [46]. Finally, the conversion led to a decrease in BMI from 40 to 32 kg/m² at 16 months postoperatively in the group described by Gonzalez et al. [47]. We also reported on 101 patients who were converted from failed VBG to RYGB and demonstrated good results on weight loss, comorbidities, and patients' symptoms [15]. The present study confirms the positive results of this conversion with a long-term EWL of 69% and a low re-intervention rate (8%).

The rate of re-operations after LAGB differs tremendously in literature from 2% to 80% [48]. Several reasons for these differences have been proposed. Firstly, results vary according to the used surgical technique, either perigastric or pars flaccida, the latter having better results especially due to a decrease in band slippages [18, 49]. In two randomized studies from Weiner et al. and O'Brien et al., the pars flaccida technique was demonstrated to be a safer technique with less complication and is therefore nowadays considered best surgical practice [18, 49]. In a previously reported study from our institution based on a study population operated more recently than the population from the present study, the re-operation rate decreased significantly from 42% to 8% after introduction of the pars flaccida technique. This was mainly due to a decrease in band slippage and pouch dilatation from 29% in the perigastric group to 4% in the pars flaccida group [48]. In the present study, this difference is not confirmed; the re-operation rate after perigastric and pars flaccida operated patients was 41% and 33%, respectively (ns). However, in this consecutive group of patients, the perigastric technique was used in 30 patients and the pars flaccida technique in 18 patients, the latter representing our first experience with this technique (reviewer no. 1, comment no. 1). Therefore, our experience with the different techniques is not comparable in this group. This might explain the non-significant difference in re-operation rate.

The second important issue explaining differences in re-operation rate after LAGB is follow-up time. In the present study, mean time between the primary operation and the re-operation because of complications after LAGB was 3 years. Most publications report on short-term results after LAGB which explains re-operation rates as low as 2%. However, a follow-up of a reasonable patient population beyond 3 years is necessary for a reliable estimation of the re-operation rate. For example, the re-operation rate in a retrospective study by Christou et al. was 16.1% after 3 years, but only one third of patients were available for follow-up [50]. In a case-controlled study by Cottam et al., the re-operation rate was 53% in the first year, decreasing to 0% in the third year. However, follow-up after 3 years was only 25% [51]. The prospective long-term study by Miller et al., with a follow-up rate of 92%, is therefore the only comparable study with a mean follow-up of 92 months and a minimum of 60 months. They reported a re-operation rate of 8% which is low compared with the 44% from the present study [14]. Whether the perigastric or pars flaccida technique was used is unclear. As mentioned above, since the introduction of the pars flaccida technique, our re-operation rate decreased to from 44% (follow-up 84 months) to 8% (follow-up of 48 months) [48].

As we previously reported, re-operations after LAGB, especially refixation of the band or replacement, are highly successful [48]. Weiss et al. reported on 73 patients who underwent a surgical revision after LAGB. After a follow-up period of 42 months, BMI decreased from 37.8 to 29.5 kg/m² [52]. Peterli et al. performed 250 operations and re-operated on 39 patients (16%) because of failed LAGB. After re-operation, 5.3% of patients developed a second failure of the band, but re-slippages were not observed [53]. These positive results of re-operations after LAGB are confirmed in the present study as only one patient had a re-slippage after refixation of the band (5%). Weight loss was successful after re-operation and more importantly, the same in patients with or without re-operation (both EWL of 54%).

In conclusion, VBG results in long-term weight loss and improvement of obesity-related comorbidities. However, because of the 65% failure rate and the necessity to perform a conversion in case of failure, we do not offer VBG to our patients nowadays. Although the re-operation rate after long-term follow-up is also high in LAGB patients, the results of these re-operations (in most cases only refixation of the band) are good. Many improvements have been made, e.g., the perigastric instead of the pars flaccida technique and low pressure–high volume bands instead of high pressure–low volume bands with a dramatic decrease in re-operation rate as a result. LAGB is the least complicated procedure in comparison with more invasive and non-reversible procedures like RYGB and BPD. Therefore, we still recommend and perform LAGB, but patients need to be informed extensively before the operation and follow-up needs to be durable and complete.