The retroperitoneal incision. An evaluation of postoperative flank 'bulge'
G. P. Gardner, L. G. Josephs, M. Rosca, J. Rich, J. Woodson and J. O. Menzoian
Division of Surgery, Boston University Medical Center, Mass.
OBJECTIVES: To determine if intercostal nerve injury is related to
postoperative flank "bulge" and to determine whether the extent of the
retroperitoneal incision is related to the incidence of flank bulge
following abdominal aortic aneurysm repair. DESIGN: Bilateral dissection of
the 11th intercostal nerve on seven cadavers; neurophysiological evaluation
of five patients, three with a flank bulge and two without; and
retrospective analysis of the extent of retroperitoneal incision and
incidence of postoperative flank bulge in 63 consecutive patients. SETTING:
Urban academic medical center. PATIENTS: Sixty-three consecutive patients
who underwent retroperitoneal repair of an abdominal aortic aneurysm and
neurophysiological evaluation of five volunteer patients. INTERVENTIONS:
Retroperitoneal repair of abdominal aortic aneurysms. MAIN OUTCOME MEASURE:
Reduction of injury to the 11th intercostal nerve by avoiding extension of
the retroperitoneal incision into the intercostal space. RESULTS: Of 14
dissections of 11th intercostal nerves, there were bifurcations of the main
trunk within the intercostal space in four, at the tip of the 11th rib in
seven, and at least 2 cm distal to the tip of the rib in three.
Neurophysiological evaluation revealed iterative discharges, polyphasia,
fibrillation potentials, and altered recruitment patterns compatible with
intercostal nerve injury in patients with a bulge but not in the opposite
abdominal wall musculature or in patients without a bulge. Seven (11.11%)
of 63 patients had a bulge. Thirty-one of 63 patients had incisions into
the 11th intercostal space in which a bulge developed in six (19.35%).
Thirty-two patients had incisions that avoided extension into the
intercostal space; a bulge developed in one (0.03%) (P = .53). CONCLUSIONS:
Postoperative bulge is related to intercostal nerve injury with subsequent
paralysis of abdominal wall musculature. Intercostal nerve injury can be
reduced by avoiding extension of the incision into the 11th intercostal
space.
