Dr Arjun Rajagopalan
BIOPSYSagittal abdominal diameter is a better predictor than body mass
index for duration of laparoscopic left colectomy
We know … • Obesity increases the technical difficulty of laparoscopic
procedures and is associated with increased operative times.
• Body mass index (BMI) is the standard by which obesity is defined.
• However, fat distribution may be predominantly in subcutaneous tissue or intra-abdominal and the two types have different risk associations. BMI does not differentiate between the two types of fat distribution.
We don’t know … • CT scan based calculations are better indices of visceral
obesity. Could they be better predictors of technical difficulty and prolonged operation times?
BIOPSY
Background
Dr Arjun Rajagopalan
BIOPSY
1: PopulationAll patients undergoing elective, laparoscopic, left colorectal surgery - 121.
Dr Arjun Rajagopalan
POPULATION CHARACTERISTICSFactor Patients (121)
Type of resectionSigmoidectomy 61%
Left hemicolectomy 17%Low anterior resection 22%
Splenic flexure takedownDone 69%
Conversion to openDone 21%
Median BMI 25.4 kg/M2
Range 16.7 - 48.6
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Measurements
Dr Arjun Rajagopalan
• 2 observers who were unaware of surgical outcomes or operative times did the measurements
1
2
34
5 6Measured at L4-5
1 = SAD - saggital abdominal diameter 2 = S-int - saggital internal diameter 3 = T-int - transverse internal diameter 4 = T-ext - transverse external diameter 5 = Sc-fat - subcutaneous fat 6 = Perim - abdominal perimeter
3 & 4 taken at the level of the vena cava/ aorta
2: Indicator variable
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3: Outcomes
Operating time (mts)
125 250
225 min
248 min
SAD > 24.8 cmSAD < 24.8 cm
Dr Arjun Rajagopalan
• Although there was a trend for the other 5 variables there was no statistically significant difference in operating time.
• There was no correlation between BMI and operating time.
p = 0.04
Sampling Observational study
Centre University hospital, Switzerland
TImeframe January 2007 - December 2010
Analysis Retrospective
Sample sizing -
Exclusions Unavaliable CT, non-resectional procedures, single-incision surgery
Numbers 121 patients
ComparisonControls Randomisation Protocols Comparability
- - - -
MeasurementTraining Blinding Multi-observers Duplication
✅ ✅ ✅ ⛔️
CHECKLIST
Dr Arjun RajagopalanDr Arjun Rajagopalan
The author(s) conclude:
This study suggests that simple linear measures taken on a CT s c a n , s u c h a s s a g i t t a l abdominal diameter, sagittal internal diameter and abdominal perimeter, may predict longer operative time in laparoscopic left colonic resections more accurately than BMI.