Large midline abdominal wall defects repair using total anterior aponeurotic flap. Preliminary anatomical study: feasibility and comparison with Ramirez’s technique

W. Staszewicz, M. Tobalem, M. Assalino, P. Morel, J. Fasel, B. Stimec

Objective

Many techniques of repair have been proposed for closure and reconstruction of large abdominal wall defects. Ramirez’s muscular component separation is widely adopted technique giving an important gain of lateral width for midline defect closure. However this method may provide an insufficient covering in the case of giant hernia or asymmetrical defect. The aim of this work is to explore the anatomical possibility of mobilising the total anterior fascial layer in a continuous flap for maximum covering of very large abdominal hernia.

Methods

Two fresh frozen cadavers without abdominal surgery or hernia history were chosen for dissection study. External oblique aponeurosis was opened from the border of costal arch to the anterior iliac spine along anterior axillary line. Detachment of external oblique fascia from the muscle was initiated laterally and carried out up to anterior rectus sheath which was open longitudinally between external and internal oblique tendon whilst keeping the continuity with external oblique fascia in order to be able to lift an uninterrupted anterior aponeurotic flap. A total of three flaps were prepared on the two cadavers. The measures of lateral and total width gain were taken. Abdominal volume increase after closing a bilateral flap on the midline was assessed. The comparison with Ramirez technique was made by taking two 1 cm thick cross-sectional slices of unilateral abdominal wall which were prepared respectively according to Ramirez and our new technique and measured before/after.

Results

Total anterior aponeurotic flap mobilisation was successfully carried out in all the three cases. Measured lateral width gain was from 12 to 15 cm on each abdominal side at the umbilical level. The cross-sectional slices of total anterior aponeurotic flaps were longer by 50 to 70% than slices dissected in Ramirez technique. There was approximately double inraabdominal volume increase after closing the abdominal wall.

Conclusion

Total anterior aponeurotic flap mobilisation is feasible and reproducible technique providing very large covering of abdominal wall defect with respect to the natural anatomical planes. It provides larger extension of musculo-aponeurotic layer than Ramirez’s technique and may be a valid alternative for repair of giant and asymmetrical hernia. Further studies and clinical tests are necessary to evaluate practical validity of this concept.

Figure 1: Comparison of Ramirez (left) and total anterior aponeuritic flap (right) technique
Figure 2: Ramirez and total anterior aponeuritic flap incision lines
Figure 3: Result of flap lifting
Figure 4: Total anterior aponeurotic flap ready to mobilization on the left side
Figure 5: Comparison of Ramirez and total anterior aponeuritic flap length
Figure 6: External oblique aponeurosis anatomy detail
Figure 7: Abdominal volume gain
Figure 8: Length gain
Figure 9: Completed flap. External oblique – rectus sheath transition zone visible