Surgical Anatomy of Transversus Abdominis Muscle for Transversus Abdominis Release: A CT-Based Study in Three Patient Groups.

BACKGROUND: The anatomy of the transversus abdominis muscle and its aponeurosis is important in transversus abdominis release surgery. We studied the CT anatomy of the transversus abdominis muscle medial to the linea semilunaris at different levels in the abdomen and measured the thickness of this muscle. METHODS: In this retrospective study, we analysed 150 abdominal computed tomography at L1, L3, and L5 vertebral levels corresponding to subxiphoid, umbilical, and suprapubic regions, respectively. The patients were divided into three groups based on age and sex: women aged 15-20 years (nulliparous), women aged 30-60 years (multiparous), and men aged 15-60 years, with each group having 50 patients. We compared the thickness of the TA muscle at the L1 level between men and women and between nulliparous and multiparous women. RESULTS: Transversus abdominis muscle was consistently present medial to the linea semilunaris at L1 vertebral level in the subxiphoid region (150/150). At the L3 vertebral level in the mid-abdomen, only eight patients had the transversus abdominis muscle there (8/150, 5%). At the L5 vertebral level in the suprapubic region, no patient had the transversus abdominis muscle medial to the linea semilunaris. The mean thickness of the transversus abdominis muscle at the L1 level was 3.4 mm, and at the L3 level, it was 1.6 mm. There was no statistically significant difference in the transversus abdominis muscle thickness between the men and women; however, a significant difference was found between the nulliparous and multiparous women, with thinner TA muscle in later. CONCLUSION: There is good transversus abdominis muscle bulk medial to the linea semilunaris for doing transversus abdominis muscle division in the upper abdomen. However, as we move towards the mid-abdomen, we have TA aponeurosis or rarely TA muscle of little bulk.

Renal Volumetry-based Prediction of the Presence of Accessory Renal Artery: Computed Tomographic Angiography-based Study with Clinical Implications on Renal Doppler.

BACKGROUND: The objective was to validate the hypothesis and evaluate whether the presence or absence of accessory renal artery can be predicted on the basis of volumetric parameters of kidney and diameter of the main renal artery (mRA). METHODS: This retrospective analysis was performed in a total of 60 kidneys in 30 patients, who had computed tomographic (CT) angiography. The kidneys were segregated into control and study groups depending on the absence or presence of accessory renal artery. The total renal volumes were measured using renal length, breadth, and height in mm3. The renal artery diameters were also measured in mm, in the postostial segment. Renal volume/renal artery diameter (V/d) was measured for each kidney in two groups, and the difference in mean V/d values (in mm2) in two groups was measured for statistical significance. RESULTS: The mean V/d value in the study group with presence of the accessory renal artery was found to be 23,444.7 mm2 (range: 16,229.1-32,490.0). The V/d value in the control group with the absence of accessory renal artery was found to be 19,717.15 mm2 (range: 13,704.6-28,000.0). The mean values in the two groups showed a statistically significant difference in the V/d with a P value of 0.001 (P < 0.05). CONCLUSION: The study suggests that the possibility of the presence of the accessory renal artery is directly proportional to the total renal volume and inversely proportional to the diameter of mRA. The use of integrated volumetric parameter (V/d) is therefore likely to play a key role in the prediction of the presence of accessory renal artery on imaging studies. Renal volumetry on CT angiography may help predict the presence of accessory renal artery and thus may have implications on renal Doppler studies.