Pilot Study of Objective Measurement of Abdominal Wall Function in Ventral Incisional Hernia Patients

Michael Parker, MD, Ross F Goldberg, MD, Maryane M Dinkins, PT, Horacio J Asbun, MD, C Daniel Smith, MD, Steven P Bowers, MD. Mayo Clinic Florida


Outcomes after ventral incisional hernia (VIH) repair are currently only measured by recurrence rate or measures of quality of life. There are no metrics available to objectively evaluate the functional outcome of abdominal wall reconstruction techniques. Therefore, our aim was to develop a non-exhaustive test of abdominal wall strength (AWS) that could be validated as a metric for abdominal wall function, using physical exam testing that requires little equipment.

Methods and Procedures:

Data were prospectively collected from 12/1/2009 through 8/31/2010 in 36 patients who were in various stages of VIH management, based on an approved protocol (IRB 09-003529). Nine patients were seen both before and after VIH repair, for a total of 45 different patient visits. Patients were tested either simultaneously or in succession by two of three different examiners. Abdominal wall function data were collected for three physical exam-based tests, all previously described as physical therapy assessment tools: (1) Double Leg Lowering (DLL), (2) Trunk Raising (TR), and (3) Supine Reaching (SR). Raw data were compared and tested for validity, and then continuous data were transformed to categorical data. Agreement was measured using the intra-class correlation coefficient (ICC) for the DLL and using Kappa for all other ordinal measures. Two estimates of the ICC and Kappa were calculated for the DLL and TR tests in assessing inter-observer reliability (examiner 1 with examiner 2, and examiner 2 with examiner 3 respectively).


Simultaneous examinations for each test yielded the following interobserver reliability values: DLL = 0.96 & 0.87, TR = 1.00 & 0.95, and SR = 0.76. Reproducibility was assessed by consecutive tests conducted 5 minutes apart with correlation as follows: DLL = 0.81, TR = 0.82, and RCH = 0.38. Due to the poorer inter-observer reliability for the SR test compared to the DLL and TR tests, the SR test was excluded from the calculation of an overall score. Based on the distribution of raw data from DLL and TR tests, DLL data were categorized into 10-degree increments, and this allowed construction of a 10-point score, based on five points per test. Median AWS score was 5 (IQR 4 – 7). Using the 10-point AWS score, there was agreement within one point for 42 of 45 encounters (93%).


The findings of this preliminary study provide evidence that the 10-point AWS score may be a measure of AWS that is both accurate and reproducible and that has potential to help clinicians objectively describe abdominal wall function in patients who are in various stages of VIH management. This score may potentially help surgeons determine those patients in need of abdominal wall reconstruction, while providing an objective measure that can track the progress in recovery after VIH repair. Further longitudinal outcomes studies will be needed.

Session: SS13
Program Number: S074

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