Bariatric surgery has provided the most consistent results in terms of weight loss and resolution of comorbidities [1]. It is also a known fact that morbidly obese patients are high risk candidates for any surgical intervention and this risk increases with increasing body mass index (BMI) [2, 3]. It has been shown that in terms of percentage of excess weight loss (%EWL), the results in morbidly obese patients have been inferior in the super obese [4, 5]. Considering these factors, selection of an appropriate bariatric procedure needs better understanding in this specific subset of patients. With no available guidelines, this subsection aims to understand the effectiveness of the various bariatric procedures available in this group of patients.

A BMI above 50 is referred as super obesity. A BMI more than 60 is referred to as super super obesity and a BMI over 70 is referred to as mega obesity. All different bariatric procedures have been described in this subset of patients including laparoscopic sleeve gastrectomy (LSG), laparoscopic roux-en-Y gastric bypass (LRYGB), laparoscopic adjustable gastric banding (LAGB), laparoscopic minigastric bypass (LMGB), laparoscopic biliopancreatic diversion/duodenal switch (LBPD/DS) with variable success among them [6–16].

LSG was initially performed as a first stage procedure prior to LRYGB or LBPD/DS in super obese patients [17, 18]. With excellent outcomes, it has evolved into a primary stand alone procedure. This staged option is still the most preferred option in many centres. This is mainly due to the simplicity of LSG in these patients compared to the bypass procedures and the reasonable outcomes with the procedure [6–8]. Lemanu et al. had shown a better %EWL of 58.9 % in the superobese patients compared to non-super obese patients with no increase in the major complication rate [6]. Daigle et al. demonstrated a %EWL of 48.3 % with LSG in elderly super obese [8]. This was slightly lesser than the LRYGB group and significantly better that LAGB which has had a poorer result overall [12].

LRYGB has also been increasingly performed in the super and super super obese. Mehaffey et al. had shown that LRYGB was well tolerated with no significant differences in post-operative outcomes and complications [4]. Schwartz et al. had demonstrated a %EWL of 55 % at 2 years and concluded that LRYGB was effective in terms of weight loss, resolution of comorbidities and improvements in quality of life (QoL) as well [9]. Giodano et al. had shown that even when compared to LAGB, there was no difference in the early complication rate with a %EWL of 55 % at 1 year [10]. Similar results have been shown in the Asian population as well [11]. It has also been shown that construction of a longer roux limb LRYGB could be more efficient in super obese patients. But with only limited data available, no firm conclusions can be drawn [19].

LBPD/DS when compared to LRYGB had greater weight loss in this group of patients. But this was at the expense of more frequent gastrointestinal side effects, more nutritional complications requiring more closer follow up and supplementations [20]. Even distal RYGB has been reported to have high mortality rates in super obese patients [15].

This now leaves us with the option of LSG and LRYGB.As discussed above Daigle et al. has shown better weight loss outcomes with LRYGB compared to LSG [8]. Zerrweck et al. also had shown that amongst the two procedures LRYGB had a significantly better weight loss at 1 year (64 % vs 44 %) [21]. Similar results has been shown by a few others too [22, 23]. Considering the above results, both LRYGB and LSG can be safely done in the super obese and super-super obese patients. But when LSG is chosen, the possibility of requiring a second stage procedure is nearly 50 % [24]. This has to be discussed with the patients in advance in the decision making.

In mega obese patients, considering the high risk profiles and the higher complication rates with malabsorptive procedures, staged procedures in the form of first stage LSG followed by a second stage LRYGB or LBPD/DS is recommended [25]. Eldar et al. also had shown that staged procedures in patients with BMI between 70 and 125 had better weight loss outcomes compared to single stage LSG/LRYGB [26].

The prevalence of morbid obesity is also rising sharply amongst the elderly patients. With the additional burden of co-morbidities in the elderly, quality of life deteriorates further. Bariatric surgery has evolved to be the primary treatment option for the morbidly obese who fail lifestyle interventions [27]. There is sufficient data on the efficacy of these surgical procedures on weight reduction and remission of the associated co-morbidities. Bariatric surgery in most centers is limited to patients <65 years of age for many reasons [27]. Concerns regarding increased perioperative complications had led to reluctance to offer bariatric surgery to older patients [28]. Scozzari et al. had reported age as an important prognostic factor in bariatric surgery and had recommended surgical indications in patients >50 years should be carefully weighed [29]. Age is considered to be an independent prognostic factor in addition to BMI, presence of diabetes mellitus and smoking in predicting postoperative mortality [30]. Santo et al. had reported increased incidence of postoperative thromboembolism in the elderly [31]. Further, increased post-operative morbidity and mortality rates in the elderly, as reported by Flum et al. and Livingston et al. has been a concern among surgeons on the safety of procedures in the elderly [28, 32].

With improvement in anesthetic techniques, standardization of surgical procedures and better patient selection, there’s now sufficient data on the safety and efficacy of the bariatric surgical procedures in the elderly [33]. Ramirez et al. had shown bariatric surgeries can be safely performed even in patients >70 years of age with low rate of complications and acceptable improvement of co-morbidities [34]. Although the elderly patients (>65 years) have a slightly prolonged hospital stay, Dorman et al. had reported no increased morbidity or mortality compared to the younger population [35]. Willkomm et al. reported no differences in post-operative complications between patients above and less than 65 years of age [33]. A recent meta-analysis of 1206 elderly patients operated for morbid obesity had reported a mortality rate of 0.25 % which is comparable to the mortality rates published by the Longitudinal Assessment of Bariatric Surgery Consortium for a younger cohort of patients (0.3 %) [36]. Most of the available data on bariatric surgery for patients >50 year has been either for LRYGB or LAGB [37–48]. In the meta-analysis by Lynch et al., perioperative complication rates and mortality were higher in LRYGB group compared to LAGB group [36]. At the same time, they had also shown better weight loss at 6 and 12 months and significantly better co-morbidity resolution in the LRYGB group [27].

Since its inception, LSG has evolved to be an acceptable standalone procedure for morbid obesity. A randomized controlled trial by Andrei Keidar et al. had shown no difference in excess weight loss or resolution of co-morbidities compared to LRYGB [49]. Yaghoubian et al. had shown comparable morbidity and mortality and although insignificant, but better weight loss in the sleeve gastrectomy group [50]. Vidal et al. had shown similar short and midterm weight loss between the two procedures and more importantly reduced complications rates in the sleeve gastrectomy group [51]. The safety and efficacy of LSG has also been demonstrated in the elderly group also. The results of Van Rutte et al. and Soto et al. have shown LSG to be relatively safe and effective procedure in the terms of weight loss and co-morbidity resolution in the elderly [52, 53]. Considering the safety profile and better results, LSG has emerged to be a better alternative to LRYGB and LAGB, as suggested by Carlin et al. [54]. But the efficacy of LSG has been questioned by a few authors. A recent meta-analysis by Li et al. had shown LRYGB to be more effective to LSG, both in weight loss and also resolution of co-morbidities [55]. There exists very limited data on the comparison of these procedures in the patient groups over 50 years of age. We have retrospectively analyzed our patients over 50 year of age where LRYGB had a %EWL of 82.76 % at 12 months which was significantly better compared to LSG with %EWL of 60.19 % [55]. This result was similar to the results reported from many other centers [37, 39, 52, 53].

In conclusion, bariatric surgery is an effective procedure for weight loss and can be safely performed even in the elderly. Although LSG has emerged to be a standalone bariatric procedure with comparable results to LRYGB in the general population, LRYGB may offer better weight loss compared to LSG with no added morbidity.

Bariatric surgery over the years has proven to be an effective treatment for all components of the metabolic syndrome. This also includes dyslipidemia along with resolution of diabetes and hypertension [56, 57]. A still unanswered question is whether this improvement in the lipid profile is merely weight-dependent or otherwise or whether its related to the inherent principles of the bariatric procedure itself [57]. This along with the predicting factors is still not very clear. With many varieties of bariatric procedures being performed, this sub-section aims to understand the effects of different bariatric procedures on the outcomes of different parameters of dyslipidemia.

Based on existing literature, it is now very clear that intestinal malabsorption has a significant role to play in improving all the parameters of dyslipidemia [58]. The same has also been shown by the Scopinaro procedure as well where intestinal malabsorption has significant impact of the improvement in lipid profiles [59]. A recent RCT had also shown that when laparoscopic duodenal switch (LDS) was compared to laparoscopic roux en Y gastric bypass (LRYGB), the reductions in total cholesterol (TC), low density lipoprotein (LDL) and triglycerides (TG) was significantly better when compared to the LRYGB group, but at the expense of more surgical, nutritional complications and gastrointestinal side-effects [60]. It is also clear that a purely restrictive procedure like a LDS, although has demonstrated some improvement especially with improvements in high density lipoprotein (HDL) and TG, it has been mainly related to weight loss [61]. With decreasing popularity of malabsorptive procedures, the focus of research has been mainly on outcomes of LRYGB and LSG.

Increasing reports are now proving LSG to be an effective alternative to LRYGB for treatment of obesity and type 2 diabetes, however its effects on dyslipidemia is hardly reported. It is now clear that the mechanisms of LSG on the resolution of type 2 diabetes is beyond just restriction like accelerated gastric emptying, increasing intestinal transit etc., which is expected to influence the outcomes of dyslipidemia as well [62, 63]. But it has been shown that the impact of LSG on lipid profile was related only to weight change and did not have a significant impact over the 5 year follow up [61, 64]. Others have reported significant improvement in all the parameters, at least in the short term, with the outcomes becoming better when combined with additional physical activity [65–68].

Two RCTs comparing LSG and RYGB have shown significant improvements in both the groups, with no differences between patients receiving a LSG or LRYGB [69, 70]. But the study populations in both these groups have been small. Except for these two trials, majority of the other authors have reported better improvements in lipid parameters among patients undergoing LRYGB procedure [6, 16–19]. A meta-analysis by Yang et al. also had shown that the outcomes after LRYGB was better compared to that of LSG. It was also noted that an age dependent trend towards better lipid improvements was noted in young patients after LSG [71].

It is also interesting to note that LSG has shown good impact in increasing HDL and reducing TG, but not in reducing total cholesterol and LDL levels [61, 66, 71–73]. Griffo et al. suggest that GLP-1 peak as the best predictor of LDL improvement, and that differential effects between the procedures could contribute the differences in LDL outcomes [72]. He had also suggested that the improvements in TG are related to improvements in insulin resistance and weight loss. Similar results were shown by Cunha et al. who had demonstrated weight loss to be major factor in this irrespective of the type of bariatric procedure [61]. This could be because obesity and insulin resistance are commonly associated with hypertriglyceridaemia and lower HDL due to an increase in hepatic very low-density lipoprotein (VLDL) cholesterol synthesis and a decreased peripheral clearance [74, 75].

Hence it can be concluded that all types of bariatric procedures have impact in improving the parameters of dyslipidemia with variable outcomes. Also more the malabsorption, the better the outcomes as shown with procedures like LBPD/DS. Amongst the more commonly performed LRYGB and LSG, LRYGB has shown better outcomes especially with the improvements in total cholesterol and LDL.