Intraoperative small bowel length measurements and analysis of demographic predictors of increased length

Measurement of human peritoneal surface area using artificial intelligence software in abdominal computed tomography

PURPOSE

The calculation of the intraperitoneal organ surface area is important for understanding their anatomical structure and for conducting basic and clinical studies on diseases related to the peritoneum. To measure the intraperitoneal surface area in a living body by applying artificial intelligence (AI) techniques to the abdominal cavity using computed tomography and to prepare clinical indicators for application to the abdominal cavity.

METHODS

Computed tomography images of ten adult males and females with a healthy body mass index and ten adults diagnosed with colon cancer were analyzed to determine the peritoneal and intraperitoneal surface areas of the organs. The peritoneal surface was segmented and three-dimensionally modeled using AI medical imaging software. In addition to manual work, three-dimensional editing, filtering, and connectivity checks were performed to improve work efficiency and accuracy. The colon and small intestine surface areas were calculated using the mean length and diameter. The abdominal cavity surface area was defined as the sum of the intraperitoneal area and the surface areas of each organ.

RESULTS

The mean peritoneal surface area of all participants was measured as 10,039 ± 241 cm2 (males 10,224 ± 171 cm2 and females 9,854 ± 134 cm2). Males had a 3.7% larger peritoneal surface area than females, with a statistically significant difference (P < 0.001).

CONCLUSION

The abdominal cavity surface area can be measured using AI techniques and is expected to be used as basic data for clinical applications.

American Society for Metabolic and Bariatric Surgery position statement on one-anastomosis gastric bypass

The following position statement is issued by the American Society for Metabolic and Bariatric Surgery in response to inquiries made to the society by patients, physicians, society members, hospitals, health insurance payors, and others regarding one-anastomosis gastric bypass as a treatment for obesity and metabolic disease. This statement is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The statement may be revised in the future as more information becomes available.

Correlation of T2DM and Anthropometric Measures with Total Small Bowel Length and Its Effects on Diabetes Remission After Bariatric Surgery

BACKGROUND

The outcome of weight loss surgery is related to several factors, and for super-obese patients, the rate of weight loss failure and weight recovery after Roux-en-Y gastric bypass (RYGB) is high. Relevant studies have shown that the weight loss effect also correlates with total small bowel length (TSBL) and biliopancreatic (BP) and Roux limbs. However, there are few studies on the relationship between TSBL and anthropometric parameters, the BP limb, the Roux limb, and weight loss effect, and no relevant reports have been reported in China.

OBJECTIVES

The objective was to study the relationship between the total length of the small intestine and anthropometric parameters in the Chinese population. The effect of the Roux limb/biliopancreatic limb (RL/BPL) ratio on weight loss and diabetes remission in RYGB patients 1 year after surgery was evaluated to find the appropriate ratio relationship.

METHODS

In this prospective study, 148 patients between the ages of 19 and 68 years who underwent laparoscopic Roux-en-Y gastric bypass were enrolled. Height, weight, BMI, the BP limb, the Roux limb, fasting blood glucose (FBG), etc., were noted. To explore the correlation between the total length of the small intestine and these values. Subsequently, the 148 patients were followed up for 1 year after surgery. The patients diagnosed with T2DM before surgery were screened out, and 56 patients were finally identified according to the postoperative follow-up, in which BPL = 50 cm and RL = 150 cm, 175 cm, and 200 cm, respectively. RL/BPL was divided into 3, 3.5, and 4 groups according to the proportional relationship to explore the relationship between RL/BPL and diabetes remission and weight loss.

RESULTS

(1) The study included 148 patients (61 women and 87 men). The mean age was 35.68 ± 10.46 years, weight = 127.46 ± 34.51 kg, height = 167.83 ± 9.16 cm, BMI = 44.94 ± 10.58 kg/m2. The average TSBL value was 714.41 ± 101.08 cm. Linear regression analysis showed that TSBL was positively correlated with height, weight, neck circumference, chest circumference, waist circumference, and Roux limb. (2) Fifty-six patients with T2DM who were followed up 1 year after surgery were divided into three groups. Group 1: BPL = 50 cm, RL = 150 cm (n = 20); group 2: BPL = 50 cm, RL = 175 cm (n = 26); group 3: BPL = 50 cm, RL = 200 cm (n = 10); RL/BPL = 3 was associated with higher weight loss than the other groups. The remission rate of diabetes did not differ between the three groups.

CONCLUSIONS

TSBL was positively correlated with height, weight, neck circumference, chest circumference, waist circumference, and Roux limb. The TSBL of males was significantly higher than that of females. Among patients with T2DM who participated in the follow-up 1 year after surgery, RL/BPL = 3 (n = 20) had greater weight loss than the other groups.

Laparoscopic small bowel length measurement: nonassociative nature of total small bowel length with anthropometric and clinical characteristics in patients undergoing bariatric surgery

BACKGROUND

Small bowel length (SBL) may have an impact on the outcomes of bariatric surgeries, but it can be difficult to make a direct association between SBL and the safety and outcome of bariatric surgeries.

OBJECTIVES

To address this issue, we set out to devise a predictive model for SBL determination based on clinical and anthropometric variables.

SETTING

An academic tertiary medical center.

METHODS

Anthropometric and clinical data, including age, sex, height, weight, and past medical history, were collected upon enrollment. SBL was measured twice during the surgery using a marked grasper. In all cases, measurements were carried out by a single surgeon. To create a predictive model, a 2-step approach was employed. In the first step, linear regression was used to determine influential variables. In the second step, all variables with a P value < .2 were entered into a multivariate regression model.

RESULTS

Overall, 961 bariatric candidates were enrolled. The mean age of the participants was 40.08 years, and 77.5% (n = 745) were female. The mean SBL was 748.90 centimeters. There was a weak but statistically significant positive correlation between SBL with both weight and height. Our univariate linear model determined only anthropometric parameters as a predictor of SBL. The multivariate model also yielded that none of the entered parameters were shown to be accurate predictors of SBL. Moreover, only 4.3% of variances were explainable by this model.

CONCLUSION

Although we found a weak positive association between height and SBL, this association lacked clinical practicality.

The use of a total bowel length measurement protocol may reduce reoperations and complications after single-anastomosis duodenal switch

INTRODUCTION

Most surgeons who perform single-anastomosis duodeno-ileal switches (SADI-S) use a pre-determined common channel length without measuring total bowel length (TBL). However, TBL varies between patients, and a standardized common channel length could contribute to malabsorptive complications and reoperations following SADI-S. The purpose of this study was to determine whether using a TBL measurement protocol to individualize common channel length would be associated with reduced reoperations and complications.

METHODS

A prospectively maintained data registry was retrospectively reviewed to identify all patients who underwent SADI-S between September 2017 and February 2022. In April 2021, we began using TBL measurements during SADI-S with 40% of the TBL used as the length for the common channel. Outcomes pre-TBL and post-TBL measurement protocol were compared.

RESULTS

A total of 119 SADI-S recipients (59 pre-TBL; 60 post-TBL) were included. The pre-TBL group had a higher frequency of reoperations (23.7% vs 1.7%, p < 0.001) and late complications (29.3% vs 3.3%, p < 0.001). The mean time to reoperation was 13.7 months in the pre-TBL group and 6.7 months in the post-TBL group (p = 0.347). Patients in the post-TBL group had significantly higher serum albumin levels at 3 months (4.2 g/dL vs 3.5 g/dL, p < 0.001), 6 months (4.1 g/dL vs 3.6 g/dL, p < 0.001), and 12 months (4.2 g/dL vs 3.8 g/dL, p = 0.023) postoperatively when compared to the pre-TBL group.

CONCLUSION

Using TBL measurements to individualize common channel length was associated with a significant reduction in reoperations and late complications following SADI-S.

How big is the little brain in the gut? Neuronal numbers in the enteric nervous system of mice, Guinea pig, and human

BACKGROUND

Despite numerous studies on the enteric nervous system (ENS), we lack fundamental knowledge on neuronal densities or total neuron numbers in different species. There are more anecdotal than actual figures on nerve counts.

METHODS

We used standardized preparation techniques and immunohistochemistry with validated panneuronal markers (human or mouse anti-HuD/C) to determine neuronal densities in specimen from the entire gastrointestinal tract of mice, guinea pig, and humans. In parallel, we measured the dimensions of the gastrointestinal regions in mouse and guinea pig. For humans, we had to rely on literature data.

KEY RESULTS

The average neuronal densities along the gastrointestinal tract were 35,011 ± 25,017 1/cm² for the myenteric and 16,685 ± 9098 1/cm² for the submucous plexus in mice, 24,315 ± 16,627 and 11,850 ± 6122 1/cm² for guinea pig myenteric and submucous plexus, respectively, and 21,698 ± 9492 and 16,367 ± 5655 1/cm² for human myenteric and submucous plexus, respectively. The total number of neurons in the ENS was 2.6 million for mice, 14.6 million for guinea pig, and 168 million for human.

CONCLUSIONS & INFERENCES

This study reports the first comprehensive nerve cell count in mice, guinea pig, and human ENS. Neuronal densities were comparable between the three species and the differences in the total numbers of enteric neurons are likely due to body size and intestinal length. The number of enteric neurons is comparable to the number of neurons in the spinal cord for all three species.

Seasonality of Primary Small Bowel Volvulus and Its Variations Based on Sex and Place of Residence, North Western Ethiopia

Background

Primary small bowel volvulus is a common surgical emergency in some parts of the globe. Its seasonal nature has not been widely researched. The main objective of this study was to assess its underlying patterns among different gender and geographical location.

Materials and methods

A hospital-based retrospective cross-sectional study was conducted from November 2020 to February 2021 at two comprehensive specialized hospitals in North West Ethiopia. The monthly count of primary small bowel volvulus was analyzed for patterns using Minitab 18. Graphical techniques such as run sequence plots, multiple box plots, and correlogram were used. Additive decomposition was also done. The degree of seasonal variation was measured in terms of seasonal indices generated for each month. A chi-square goodness-of-fit test at p < 0.05 was applied to determine statistical significance.

Results

A total of 235 patients were found to have surgically confirmed diagnosis of primary small bowel volvulus over six years. Most were males (77.4%) and from rural residence (73.2%). The mean age in years was 40.5 (±16.7). Overall, 179 (76.2%) of the total cases, 148 (81.3%) of males, and 138 (80.2%) of rural cases were admitted during June through November.

Conclusion

Seasonal variation was found to be a feature of primary small bowel volvulus. Knowing its seasonal nature helps raise the threshold of suspicion among health care providers to pass timely clinical decisions particularly in resource-limited setups.

Repository Describing the Anatomical, Physiological, and Biological Changes in an Obese Population to Inform Physiologically Based Pharmacokinetic Models

Background

Obesity is associated with physiological changes that can affect drug pharmacokinetics. Obese individuals are underrepresented in clinical trials, leading to a lack of evidence-based dosing recommendations for many drugs. Physiologically based pharmacokinetic (PBPK) modelling can overcome this limitation but necessitates a detailed description of the population characteristics under investigation.

Objective

The purpose of this study was to develop and verify a repository of the current anatomical, physiological, and biological data of obese individuals, including population variability, to inform a PBPK framework.

Methods

A systematic literature search was performed to collate anatomical, physiological, and biological parameters for obese individuals. Multiple regression analyses were used to derive mathematical equations describing the continuous effect of body mass index (BMI) within the range 18.5–60 kg/m² on system parameters.

Results

In total, 209 studies were included in the database. The literature reported mostly BMI-related changes in organ weight, whereas data on blood flow and biological parameters (i.e. enzyme abundance) were sparse, and hence physiologically plausible assumptions were made when needed. The developed obese population was implemented in Matlab^® and the predicted system parameters obtained from 1000 virtual individuals were in agreement with observed data from an independent validation obese population. Our analysis indicates that a threefold increase in BMI, from 20 to 60 kg/m², leads to an increase in cardiac output (50%), liver weight (100%), kidney weight (60%), both the kidney and liver absolute blood flows (50%), and in total adipose blood flow (160%).

Conclusion

The developed repository provides an updated description of a population with a BMI from 18.5 to 60 kg/m² using continuous physiological changes and their variability for each system parameter. It is a tool that can be implemented in PBPK models to simulate drug pharmacokinetics in obese individuals.

The Importance of Intestinal Length in Triglyceride Metabolism and in Predicting the Outcomes of Comorbidities in Laparoscopic Roux-en-Y Gastric Bypass-a Narrative Review

In this narrative review, we will appraise if modification of the length of bypassed small intestine based on measured total small intestinal length could optimize the outcomes of the laparoscopic Roux-en-Y gastric bypass (LRYGB). We provide a summary of carefully selected studies to serve as examples and to draw tentative conclusions of the effects of LRYGB on remission of comorbidities. As the heterogeneity of the included studies varied in terms of outcomes, type of study, length of the bypassed small intestine, and the follow-up, a common endpoint could not be defined for this narrative article. To achieve efficient metabolic outcomes, it is important to carefully choose the small intestine length excluded from the food passage suited best to each individual patient.

Variability of Length of Small Intestine in Indian Population and Its Correlation with Type 2 Diabetes Mellitus and Obesity

PURPOSE

Previous studies have correlated small intestinal length with gender, age, weight, height and ethnic background. Some studies have reported a positive correlation of small intestinal length to body mass index (BMI). Some studies have shown that bypassing proximal small intestine can result in diabetes mellitus (DM) control. Present study was conducted to find correlation of small intestinal length with BMI and DM.

MATERIALS AND METHODS

Two hundred eighty-three patients aged between 18 and 60 years who underwent open or laparoscopic abdominal surgery were included. Height, weight, BMI, random blood sugar (RBS), HbA1c, etc. were noted. A standard 30-cm umbilical tape with 10 cm marking was used to measure the length of small intestine in laparotomy patients, whereas lap bowel graspers with marking of 10 cm on the shaft was used for laparoscopy patients. Statistical significance of normally distributed continuous variables was tested using independent sample t test. Spearman rank correlation was used to test association between two ranked variables.

RESULTS

The mean small intestinal length in Indian population was 777.1 cm with a standard deviation of 186.2 cm. Mean length of small intestine was significantly higher in patients who had HbA1c ≥ 6.5% and RBS levels ≥ 200 mg/dL. HbA1c and RBS showed significant but a weak positive correlation with length of small intestine. BMI did not show significant correlation with length of small intestine.

CONCLUSION

Small intestinal length had significant but a weak positive correlation in patients who had HbA1c ≥ 6.5% and RBS levels ≥ 200 mg/dL.

Correlation Between the Total Small Bowel Length and Anthropometric Measures in Living Humans: Cross-Sectional Study

BACKGROUND

Variation in the outcome of bariatric surgery is still an unraveled phenomenon. This variation could be multifactorial. Several reports implicate the total small bowel length (TSBL) in this process. However, the basic information regarding the normal bowel length and its relation to the anthropometric parameters of the living subject is scarce. This study aims at reporting the normal total bowel length in living adult humans and its correlation with the anthropometric parameters.

METHODS

This study included 606 participants (380 females and 226 males). Their mean age was 39.8 ± 11 years, weight = 135.7 ± 29.7 kg, height = 165 ± 9 cm, and BMI = 49.5 ± 7.5 kg/m². The mean TSBL was 630 ± 175 cm. There was a statistically significant but very weak positive correlation but between the TSBL and both weight and height. Males had significantly higher weight and were significantly taller compared with females. TSBL was significantly longer in males at 661.5 ± 186 cm versus 612 ± 164 cm in females.

CONCLUSION

The study reports an average TSBL greater than what is reported in the literature from living humans with a greater range of variation. There is no clinically important correlation between the TSBL and the weight and height of the individual participants in this series.

Repeated stretched or non-stretched small bowel length measurements in healthy individuals

Objectives

The aim of the present study was to contribute to the establishment of a standard method of small bowel measurement by comparing repeated small bowel length measurements with and without stretching in healthy individuals.

Material and Methods

Small bowel measurement was randomly performed in 24 healthy liver donors. Three repetitive measurements were performed with complete stretching in 12 cases; whereas, 3 consecutive measurements were made without any stretching in the other 12 patients. Living donor hepatectomy continued uneventfully in all cases.

Results

In the non-stretched group, the second measurement was 199 cm shorter than the first measurement (p <0.001). In the third measurement, this shortening had increased further, and the difference from the first measurement was 234 cm on average (p <0.001). In the stretched group, a shortening of approximately 135 cm between the first and second measurements was noted. In the third measurement, an improvement of 4% was observed in contrast to the non-stretched method, with a mean reduction of 105 cm in the small bowel length compared with the first measurement (p <0.001).

Conclusion

Stretching technique can reduce error rate in repeated small bowel measurements.

Three-dimensional CT enterography versus barium follow-through examination in measurement of remnant small intestinal length in short bowel syndrome patients

PURPOSE

To evaluate the feasibility and accuracy of remnant small intestinal length measured by barium follow-through (BaFT) examination and three-dimensional CT enterography (CTe).

MATERIALS AND METHODS

Twenty-nine consecutive short bowel syndrome patients (SBS) who underwent BaFT, CTe, and prior surgical measurements of small intestine were included. Measurements of total remnant small intestinal length on BaFT and CTe were compared to surgical measurements using Spearman's rank correlation coefficients, Bland-Altman plots, and paired t test.

RESULTS

The average remnant intestinal length was 73.1 ± 37.2 cm according to surgical measurement. There was a significant positive correlation between CTe and surgical measurement (r² = 0.99; p < 0.0001), and a relatively weaker correlation between BaFT and surgical measurement (r² = 0.71; p < 0.001). Compared with surgical measurement, the percentage differences of CTe and BaFT were 5.71 ± 6.71% and 27.14 ± 18.41% (mean ± SD), respectively. Furthermore, Bland-Altman plots showed good agreement between CTe and surgical measurement, whereas relatively poor agreement between BaFT and surgical measurement. However, significant difference was found among the three measurement methods by paired t test (p < 0.0001).

CONCLUSIONS

Assessment of remnant small intestinal length by CTe is accurate and acceptable for clinical application, whereas BaFT is less accurate although BaFT is more convenient and cheaper for clinical application. And CTe can provide a cost-effective and noninvasive determination of remnant small intestinal length in planning surgical and nutritional intervention in SBS patients.

The Distal Predilection of Small Bowel Neuroendocrine Tumors

BACKGROUND

The small bowel (SB) is the most common site of neuroendocrine tumors (NETs) of the GI tract. These are described as being predominantly jejunoileal, but their exact locations within the SB have not been well defined. We sought to determine prospectively the spectrum of SBNET locations.

METHODS

Patients undergoing exploration for SBNET primaries had measurement of bowel length, tumor locations, and resection length recorded. Correlations of clinicopathologic factors were performed, and analysis done utilizing Welch's t test, Chi square test, and the Kaplan-Meier method.

RESULTS

Measurements were recorded in 123 patients, 107 of whom had complete information. Multifocal tumors (MTs) were found in 69 (56%) and unifocal (UTs) in 54 (44%) patients. Only 1 of 107 patients had a tumor within 100 cm of the ligament of Treitz (LT), whereas 77 of 107 (72%) had tumors within 100 cm of the ileocecal valve (ICV). No MTs were found within 100 cm of LT, whereas 41 of 60 (68%) patients had all (10) or at least one tumor (31) located within 100 cm of the ICV. MTs required a mean resection length of 108 versus 59 cm for UTs (p < 0.01). Seventy-seven percent of UTs (36/47) were within 100 cm of ICV. Tumors occurring only between > 100 cm from the LT and ICV were seen in 29 of 107 (27%) patients.

CONCLUSIONS

SBNETs are frequently multifocal and most commonly located within 100 cm of the ICV. SBNETs are less prevalent proximally in the small bowel, which may result from anatomic differences in enterochromaffin cell density, hormonal factors, or environmental exposures in the distal SB.

Preoperative Prediction of Small Bowel Length Using CT Scan and Tridimensional Reconstructions: a New Tool in Bariatric Surgery?

PURPOSE

During Roux-en-Y-gastric Bypass, the limb lengths are preoperatively determined regardless of individual small bowel length (SBL), which presents a great variability. Few studies highlighted anthropometric factors associated with SBL, and none attempted to predict SBL preoperatively.

OBJECTIVE

The aim of this study is to evaluate factors correlated to SBL (anthropometric and radiologic) and to establish a preoperative SBL prediction.

MATERIAL AND METHODS

In this single-center prospective study, 30 adult patients who underwent laparotomy with a preoperative CT scan were included. Intraoperative SBL measurement was performed with an umbilical tape. Anthropometric parameters were age, gender, height, and BMI. 2D radiological measurements consisted of subcutaneous thickness, abdominal diameters, waist circumference, and mesenteric root length. 3D radiological volumetric reconstructions consisted of whole small bowel and mesentery (WSBM), lean small bowel and mesentery (LSBM), and fat small bowel and mesentery (FSBM).

RESULTS

Mean intraoperative measurement of SBL was 531 ± 105 cm. Among the clinical and radiological measurements, the FSBM volume presented the greatest dispersion. Height (p < 0.02) and LSBM volume (p < 0.01) were significantly correlated to the SBL in univariate analysis. LSBM volume was the only measurement significantly associated with SBL in multivariate analysis (p < 0.006). From the multivariate model, a formula was created to predict SBL. The mean percentage difference between predicted and intraoperative SBL measurements for all patients was 13.7%, and 8.4% for obese patients.

CONCLUSION

LSBM volume is significantly correlated to the SBL. A preoperative SBL prediction with low percentage error could be performed with LSBM volume.

Diarrhea after bariatric procedures: Diagnosis and therapy

Diarrhea after bariatric procedures, mainly those with malabsorptive elements including Roux-Y Gastric Bypass and Biliopancreatic Diversion, is common and an essential determinant of quality of life and micro- and macronutrient deficiencies. Bariatric surgery is the only sustainably successful method to address morbid obesity and its comorbidities, particularly gaining more and more importance in the specific treatment of diabetic patients. Approximately half a million procedures are annually performed around the world, with numbers expected to rise drastically in the near future. A multitude of factors exert their influence on bowel habits; preoperative comorbidities and procedure-related aspects are intertwined with postoperative nutritional habits. Diagnosis may be challenging owing to the characteristics of post-bariatric surgery anatomy with hindered accessibility of excluded segments of the small bowel and restriction at the gastric level. Conventional testing measures, if available, generally yield low accuracy and are usually not validated in this specific population. Limited trials of empiric treatment are a practical alternative and oftentimes an indispensable part of the diagnostic process. This review provides an overview of causes for chronic post-bariatric surgery diarrhea and details the particularities of its diagnosis and treatment in this specific patient population. Topics of current interest such as the impact of gut microbiota and the influence of bile acids on morbid obesity and especially their role in diarrhea are highlighted in order to provide a better understanding of the specific problems and chances of future treatment in post-bariatric surgery patients.

Influence of repeated measurements on small bowel length

Purpose

Measurement of small bowel length (SBL) is a common procedure in gastrointestinal surgery. When required, repeated SBL measurements can be done during surgery. Our aim was to evaluate whether these repeated measurements differ in SBL results.

Methods

Small bowel length was measured during laparotomy in 28 patients between ligament of Treitz and caecum, using a standard measure, two times in each patient consecutively by two different surgeons from the anti-mesenteric border of the bowel.

Results

The median age was 33 (19–67) including 18 male. There were 16 healthy donors for living related liver transplantations. Second measurements, performed immediately after the first measurements, significantly shortened the measured SBLs in the same patients (580 ± 103 vs. 485 ± 78 cm, p < 0.001).

Conclusions

During surgery, repeated length measurements caused contractions in the small bowel and this resulted to a significant decrease in the SBL. This should be keep in mind to prevent mismeasurements.

Small Bowel Limb Lengths and Roux-en-Y Gastric Bypass: a Systematic Review

There is currently no consensus on the combined length of small bowel that should be bypassed as biliopancreatic or alimentary limb for optimum results with Roux-en-Y gastric bypass. A number of different limb lengths exist, and there is significant variation in practice amongst surgeons. Inevitably, this means that some patients have too much small bowel bypassed and end up with malnutrition and others end up with a less effective operation. Lack of standardisation poses further problems with interpretation and comparison of scientific literature. This systematic review concludes that a range of 100-200 cm for combined length of biliopancreatic or alimentary limb gives optimum results with Roux-en-Y gastric bypass in most patients.

Bowel length: measurement, predictors, and impact on bariatric and metabolic surgery

BACKGROUND

Small bowel length (SBL) determines the caloric absorptive capacity. The aim of this study was to evaluate SBL to identify patient-specific predictors and the interrelationships of SBL with anthropometric variables.

METHODS

Sex, age, and weight were recorded at the time of surgery when SBL and the estimated jejunal length (JLe) were measured by 3 different methods.

RESULTS

The mean SBL of 443 patients undergoing laparotomy (78% female) was 690±93.7 cm (range 350-1049 cm). Sex was correlated with SBL, as men had a longer small bowel than women (729±85 versus 678±92, P<.0001) and were significantly taller (173±8.2 versus 161±6.9, P<.001). Age did not correlate with SBL. The differences in length between fully stretched small bowel and nonstretched small bowel and between fully stretched small bowel and laparoscopic bowel were 137±19 cm and 32.4±11.4 cm, respectively. In a multivariate linear regression analysis model that included sex, age, height, and weight, only height was significantly correlated with SBL (P<.00001) and explained 12% of the variance in SBL. Sex, age, height, and JLe, but not SBL, were statistically highly significant in predicting 75% of the variance of body weight.

CONCLUSIONS

A positive association between height and SBL was found. Sex, age, height, and JLe may be strong predictors of weight. Individual JLe may be of importance in determining the weight loss and resolution of metabolic co-morbidities. Measuring the SBL can prevent the risk of nutritional consequences in malabsorptive, revisional, and metabolic procedures.

Effects of experience and reference tools on laparoscopic length measurements

INTRODUCTION

The accuracy of surgeons, and surgeons-in-training performing laparoscopic intestinal measurements is unknown. We evaluated the accuracy and precision of laparoscopic length measurements using a box-trainer model with and without the aid of a measuring tool.

METHODS

Surgical attendings, residents, and medical students were studied. A 500 cm length of rope was placed within a laparoscopic box trainer. Subjects completed two length measurements (LM). Participants measured 150 cm of rope for LM #1 and repeated the task using a 10-cm suture as a reference for LM #2. Measurement accuracy was tested by comparing mean LM between training level groups using an independent t test. Measurement precision was tested by comparing the mean deviation of LM from 150 cm.

RESULTS

40 attendings, 40 residents, and 50 medical students were studied. In LM #1, there were no differences in mean length accuracy measured between training level groups. Residents significantly underestimated the true 150 cm length (p < 0.05). When LM #1 and LM #2 were compared, attending accuracy did not change but precision increased significantly (p < 0.01). Resident precision also significantly increased with the measuring tool (p < 0.001) and trended toward improved accuracy (p = 0.08). Student accuracy did not change, but a similar significant increase in precision was observed with the measurement tool (p = 0.001). Attendings performed both measurements faster than residents and students (p < 0.05). Residents performed faster than the students for both measurements (p < 0.05). Time for task completion significantly increased in medical students with the use of the measurement tool (p = 0.026).

CONCLUSIONS

These data suggest that use of a measurement tool in laparoscopic length measurement will yield better precision with no effect on operative time or procedural flow in more experienced operators. Standardization of methods of use and optimal training techniques remains to be determined.