Screening of potential patients for the trial was conducted on all patients presenting to the surgeon's office with a possible hernia. Unless unequivocal contraindications were present, patients were scheduled to see the participating surgeon to confirm that they were candidates for the study. Informed consent for participation in the trial and for randomization was then obtained. Consent and patient-centered data collection documents were translated into Spanish and French. After the patient provided informed consent and all inclusion criteria were satisfied, the Study Coordinator telephoned the center where the staff confirmed eligibility. The patient was then randomly assigned to either operation or watchful waiting with the randomization stratified by: participating site, whether the hernia is primary or recurrent, and bilateral or unilateral hernia. At the time of screening, an anonymous list was maintained of patients who were not enrolled; reasons for ineligibility or non enrollment were recorded in addition to patient age and categories of co-morbidities, but no names or personal identification items were recorded. These data were used to determine recruitment percentage and whether important differences exist between enrolled and non enrolled patients.

The procedure described by Lichtenstein was the control operation. A videotape by Amid, presented at the 1998 Clinical Congress of the American College of Surgeons, was used as the standard for the Lichtenstein operation. The PIs from each institution reviewed the video at an investigators' meeting before patient recruitment began and details of the procedure were agreed upon; all surgeons participating in the trial were willing to follow the procedure as described. Local anesthesia was recommended but not required.

Several important technical features of the operation were adhered to strictly. The prosthesis had to be a minimum of 15 cm in width and 7.5 cm high and overlap the pubic tubercle onto the anterior rectus sheath. A running, non absorbable monofilament suture was used to secure the inferior border of the prosthesis beginning on the anterior rectus sheath at least 2 cm medial to the pubic tubercle. The suture was continued laterally on either side of the pubic tubercle and then along the shelving edge of the inguinal ligament to the internal ring. Interrupted sutures were used only if it was necessary to incorporate Cooper's ligament into the repair because of extensive destruction of the inguinal floor or a femoral hernia. A slit in the lateral end of the mesh was cut to produce a narrow (1/3-width) tail below and a wider (2/3-width) tail above. The spermatic cord was positioned between the two tails. The inferior surface of the wider tail was sutured to the inferior surface of the narrow one and the shelving edge of the inguinal ligament, thereby creating a shutter valve that acts as a snug-fitting internal ring. This step is considered particularly important to prevent an indirect recurrence. Simple linear reapproximation was not permitted. The tails could be trimmed but a minimum of 6 cm lateral to the internal ring was required. Written postoperative instructions were provided to each patient.

Watchful waiting patients were taught about dangerous hernia symptoms and written instructions and explanations were provided. Subjects were told to contact their physician if problems developed. They were seen in person at 6 months, and yearly after enrollment.

Follow-up: Watchful waiting patients were given written instructions to watch for hernia symptoms and contact their physician if problems developed. Patients were examined at 6 months and yearly after enrollment.