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Quan et al. Bowel length and outcome of bariatric surgery

length based on the length of small bowel left, and the currently unknown is whether there is an impact of
patient’s anatomy, and this configuration is known as the total/bypassed bowel length on the incidence of
[7]
the proximal or standard gastric bypass. [9,10] A distal complications and failure. A patient’s preoperative total
gastric bypass differs by having a fixed CL length of bowel length may indeed have an effect on the potential
100-150 cm which leaves a variable AL and BPL length weight loss achievable with an RYGBP and also
that may end up being very long or conversely very whether they are at risk of regaining weight with a very
short. long bowel that minimizes the effect of the diversion or
developing malnutrition with a very short one that has
The hypothesis is that a distal bypass can lead to the very limited absorptive capacity. As such knowing
better weight loss outcomes due to a longer diversion a patient’s total bowel length may be useful in the
of the digestive tract and a shorter section of common future as a predictor of outcomes and would be useful
bowel for absorption. [11] The small intestine has a in patient selection when choosing diversional options
huge variability in length among patients and can vary and limb lengths to maximize benefit and minimize
between 300 to 1,000 cm. [12] Because of this, the CL adverse outcomes.
length can theoretically range from 50 to 850 cm in
a proximal gastric bypass as intestinal lengths are Future studies aim to set a standard into intestinal
not routinely measured before reconstruction of the lengths for optimal outcomes, [11] but very few studies
digestive continuity. seek to examine the patients’ total bowel length and
whether this has an influence on the success rates of
Despite the RYGBP’s success rate in reversing obesity proximal and distal bypasses. [28] Navez et al. [26] and
and its comorbidities, the outcomes can be variable. Savassi-Rossa et al. [36] show that there may be no
An RYGBP may fail when it’s primary outcome is relation between CL length and weight loss though
not achieved, whether this is resultant from either an there is a small sample size and follow-up time to
insufficient weight loss from what is predicted [13-15] or assess weight regain or the occurrence of malnutrition
the patient regains weight shortly after the procedure is is short.
performed. [16-18] Conversely, other patients may develop
significant malnutrition when there is not enough Further studies are required to assess if bowel length
absorption of key nutrients [19-21] which may even lead has a long-term influence on outcomes and whether
to a functional short bowel syndrome which despite its routine measurement of bowel length can optimize
rarity is a far more severe complication and can occur this. Several studies have mentioned the technical
more frequently the shorter the CL length is. [22-24] challenges in measuring bowel length [37-39] and in the
superobese patient, a high level of visceral fat will
Studies have assessed the effect of the limb lengths only complicate this further. A standardized method
on weight loss, while others have addressed the of bowel measurement should, therefore, be agreed
malnutrition effect. Many studiesconcur that the CL upon to make accurate comparisons possible, and this
length and AL length do not affect the amount of could be a combination of preoperative radiographic
potential weight loss that a patient can achieve [25-28] bowel measurements and intraoperative laparoscopic
though Tran et al. [29] has suggested the use of a
distal bypass is an effective revision for a failed loss measurements.
of weight on a standard bypass. There is certainly a
range of results on whether proximal or distal bypasses These studies have the potential to answer a
have more pronounced effects on the metabolic and fundamental question on the way we perform
endocrine systems as reported by Risstad et al. and diversional surgeries in an attempt to optimize the
[9]
Ramos et al. [30] Distal bypasses may also be related outcome. There is no doubt that there are several other
to increased rates of complication. [10,31] Longer BPL variables that might influence the outcome - such as
lengths have been found to result in both higher weight genetic factors. However, we believe that the question
loss and malnutrition rates with the two are often raised - which cannot be ignored - is at the core of
correlating. [21,32,33] understanding the pathophysiology of the procedure,
which is not fully understood until now.
The reasons for failure may have a technical
component and could be related to constructed bowel Authors’ contributions
length from diversion, but studies by Maleckas et al., [16] Manuscript concept: M. Bekheit
Shantavasinkul et al. [34] and Perrone et al. [35] allude to a Literature search and drafting: V. Quan, F.P.M. Cooper
more complex etiology and suggest patient factors play Critical revision and approval: V. Quan, F.P.M. Cooper,
a significant role in determining the outcome. What is M. Bekheit

96 Mini-invasive Surgery ¦ Volume 1 ¦ September 30