The paradox of Zeno in bariatric surgery weight loss: Superobese patients run faster than morbidly obese patients, but can't overtake them

Abstract

Introduction: Superobesity (SO) is defined as a BMI > 50 Kg/m², and represents the extreme severity of the disease, resulting in a challenge for the surgeons.

Methods: In this retrospective study we aimed to compare the outcomes of SO patients compared to morbidly obese (MO) patients.

Results: We included in this study 154 MO patients, with a median preoperative BMI of 40.8 kg/m², and 19 SO patients with median preoperative BMI of 54.9 kg/m². The MO patients underwent sleeve gastrectomy (SG) in 62 (40.3%) cases, laparoscopic Roux-and-Y gastric bypass (LRYGBP) in 85 (55.2%) cases and One-Anastomosis Gastric Bypass (OAGB) in 7 (4.5%) cases. underwent OAGB. The patients in the SO group were submitted to SG in 11 (57.9%) cases, LRYGBP in 5 (26.3%) cases, and OAGB in 3 (15.8%). At 24-month follow-up, an excess weight loss (EWL) >50% was achieved in 129 (83.8%) patients in the MO group and in 15 (78.9%) in the SO group (p = 0.53). A BMI < 35 kg/m² was achieved in 137 (89%) patients in the MO group and from 8 (42.2%) patients in the SO group (p < 0.001). The total weight loss was significantly directly related to the initial BMI. Superobesity was identified as independent risk factor for surgical failure when considering the outcome of BMI < 35 kg/m².

Discussion: Our study confirms that, although SO patients tend to gain a greater weight loss than MO patients, they less frequently achieve the desired BMI target. In this setting, it should be necessary to re-consider malabsorptive procedures as first choice.

Keywords: laparoscopic Roux-and-Y gastric bypass; laparoscopic sleeve gastrectomy; morbidly obese patients; obesity surgery; superobesity.

Figure 1

Scatter diagram representing the correlation between preoperative BMI and total weight loss (TWL). The correlation test demonstrated that preoperative BMI > 50 Kg/m² was significantly associated with a higher TWL (correlation coefficient = 0.4914; p < 0.001).

Figure 2

Forest plot of results of multivariate analysis. Results are reported in logarithmic scale. In (A) are reported the results of logistic regression considering the outcome of EWL > 50% at 24 months; the only significant variable predictive of surgical failure was SG (OR = 2.816; 95%CI = 1.0741–7.3837; p = 0.0353). In (B) are reported the results of logistic regression considering the outcome of BMI < 35 Kg/m² at 24 months. The only significant variable predictive of surgical failure was superobesity (OR = 14.04; 95%CI = 3.5443–55.6861 p = 0.002). OR, odds ratio; OSAS, obstructive sleep apnea syndrome; GERD, gastroesophageal reflux disease; SG, sleeve gastrectomy; OAGBP, one-anastomosis gastric bypass.