ANORECTAL RECONSTRUCTION AFTER ABDOMINOPERINEAL RESECTION - EXPERIENCE WITH DOUBLE-WRAP GRACILOPLASTY SUPPORTED BY LOW-FREQUENCY ELECTROSTIMULATION

PURPOSE: The aims of the study contained herein were to analyze the ef ficacy and safety of a chronically electrostimulated double-wrap graci loplasty for restoration of continence after a curative abdominoperine al resection for rectal carcinoma and to evaluate late results of a st imulation protocol that was begun early. METHODS: During the last six years, 31 consecutive patients underwent this procedure: in 24 patient s, electrostimulated double-wrap graciloplasty was performed simultane ously with abdominoperineal resection for lower rectal cancer; 7 stric tly selected patients underwent conversion to an abdominal stoma follo wing previous abdominoperineal resection (mean length of time from sto ma creation, 71.4 months). Anorectal reconstruction was performed foll owing a surgical scheme already standardized since 1985 in 102 patient s: after abdominoperineal resection, the distal colon was pulled throu gh to the perineum and surrounded by both gracilis muscles following a n ''alfa and new-sling'' configuration; using platinum-iridium electro des, both muscles were then connected to a pulse generator, which was implanted subcutaneously in the abdomen. All surgical steps were perfo rmed during the same surgical session to allow early postoperative sti mulation of the transposed muscles. A contemporary covering stoma was abandoned as a standard procedure; the distal colon was left closed fo r a few postoperative days, then it was resected and sutured to the pe rineum under local anesthesia. Eighteen patients underwent preoperativ e or postoperative radiotherapy or both, without any significant adver se outcome. To increase gracilis resistance to prolonged ''tonic'' con traction, patients underwent a chronic, low-frequency stimulation prot ocol. In the last 11 patients, a new ''over-the-nerve and intramuscula r'' implant was adopted to optimize fiber recruitment and to reduce el ectrostimulation thresholds. At regular intervals, all patients were e valuated using continence scores and questionnaires, electromanometry, endoluminal ultrasound study, and defecography. RESULTS: Twenty-six o f 31 patients were evaluable for continence, with a mean length of fol low-up of 37.8 (range, 4-68) months; 3 patients died because of cancer recurrence, 1 underwent conversion to an abdominal stoma, and 1 is wa iting for stoma closure. Continence to liquid and solid stools was ach ieved in 22 patients (85 percent), and electromanometry findings confi rmed a good muscular contraction postoperatively and during follow-up intervals. No postoperative mortality (40 days) was observed; the post operative complication rate was high (22 percent), but early treatment (drainage and temporary diversion in 7 patients) led to favorable out comes (4 resolutions, 3 partial muscular impairments). Four stimulator s had to be temporarily explanted because of late complications, and t wo stimulators had to be replaced because of battery exhaustion after three years of use with high stimulation parameters. A significant dif ference was observed comparing full-contracting threshold after intram uscular (14 patients) and the new over-the-nerve and intramuscular imp lant technique. CONCLUSIONS: The study contained herein confirms the e fficacy of the surgical scheme we have adopted since 1985 to reconstru ct sphincteric apparatus after abdominoperineal resection of the rectu m. The ''one-step'' timing of surgical and electrostimulation-related procedures and the early start of stimulation did not show a significa nt increase in the complication rate and did not produce noticeable mu scular or nerve damage. Adoption of chronic electrostimulation protoco ls using implantable devices increased the rate of fully continent pat ients; nevertheless, the overall cost for devices and medical staff du ties was high, and a small increase of late morbidity was observed. Fi nally, the preliminary experience with our new technique of electrode implants encourages further application.