Fistula formation after large loop excision of the transformation zone in patients with cervical intraepithelial neoplasia

This is the first report in the medical literature of two cases of rectal and bladder fistula formation after large loop excision of the transformation zone. Large loop excision of the transformation zone (LLETZ) is a well-known and effective method for the treatment of high-grade squamous intraepithelial lesions (HG-SIL). It is usually colposcopically guided and has the advantage of being simultaneously diagnostic and therapeutic. Since there is only minimal tissue damage, the specimen can be used to rule out invasive carcinoma. Complications of the LLETZ procedure are few and include mainly intraoperative and postoperative bleeding, infection and, rarely, infertility caused by cervical stenosis from damage to the cervical channel. We present two cases of rectovaginal and vesicovaginal fistula, which occurred as a consequence of LLETZ. Our review of the English literature of the last 20 years yielded no similar reports. The purpose of this article is to point out the potential hazards of loop electrosurgical excision. A 40-year-old woman, married, with two children, was found to have a cervical intraepithelial lesion (CIN) III on cervical biopsy and was referred to our department for LLETZ. She had had two normal vaginal deliveries. Her medical history was significant for carcinoma of the colon, diagnosed four years previously, which was treated with left hemicolectomy followed by radiation and systemic chemotherapy. The pre-operative colposcopic evaluation revealed a distinct acetowhite lesion, 30 mm in diameter, with clear margins. It showed a mosaic vascular pattern and punctation. No obvious invasion was apparent. The LLETZ procedure was performed under general anesthesia in the operating theater. The cervical tissue was removed in two pieces. The day after the procedure, the patient felt urine leakage, but came for examination only four days later. Methylene blue dye was injected into the bladder through a Foley catheter, and a vesicovaginal fistula was detected near the cervix. Cystoscopy demonstrated a fistula opening into the right lower bladder wall and measuring 1.5 cm in diameter. Intravenous pyelography showed intact ureters. The patient was treated with bladder catheterization and antibiotics for two weeks, followed by fistulectomy and immediate closure. Follow-up was uneventful. A 44-year-old woman, married, with three children, was referred to our department for treatment of CIN III diagnosed by colposcopy-guided cervical biopsy. During the vaginal examination, a small retractable cervix was noted. The pre-operative colposcopic evaluation showed a lesion, 26 mm in diameter, of mosaic vascular pattern with acetowhite patches separated by blood vessels. No obvious invasion was suspected. LLETZ was performed under general anesthesia, and the tissue was removed in one piece. Because of cervical bleeding, a few sutures were placed at the cone site immediately after the procedure. Two weeks later the patient complained of an offensive discharge from the vagina. Vaginal examination revealed a small aperture in the rectovaginal septum, raising the suspicion of rectovaginal fistula. Gastrografin enema localized the fistula at 8 cm from the anus, and findings were confirmed with solonoscopy and computed tomography scan; the fistula measured 1.5 cm in diameter. Combined low anterior resection with abdominal hysterectomy was successful. Follow-up was uneventful, and there was no need for colostomy. Histologic examination of the fistula edges revealed no abnormalities. To the best of our knowledge, this is the first report of fistula formation after LLETZ. The LLETZ procedure is the treatment of choice for high-grade squamous intraepithelial lesions. It is performed with a large loop of thin wire, which forms a diathermy electrode and allows a deep excision of the transformation zone with minimal tissue damage. Most surgeons prefer to excise the tissue in one piece. Thus, the loop size is chosen according to the diameter of the transformation zone. The procedure is associated with a high cure rate of about 97%, a low recurrence rate of 4% is reported, similar to those of cold knife and laser conization (1, 2). The significant advantages of LLETZ compared to laser or cold knife conization are shorter operative time, less handling of the tissue, reduced bleeding and discomfort for most of the procedure, and use of local instead of general anesthesia in most cases (3, 4). Moreover, there is no hazard to the surgeon’s eyesight, and equipment breakdown occurs less often, leading to higher efficiency at a relatively lower cost (5-7). Both patients described here were operated on by well-experienced gyneco-oncologists and, based on the history and physical examination of the patients, both procedures were done under general anesthesia. We believe that contributory or predisposing factor to the fistula formation, in addition to the effort to do the conization with minimum cuts, was apparently the condition of each patient at presentation: one was after pelvic irradiation and the other had an almost invisible retracted cervix. The latter finding was also mentioned as a risk factor in the single reported case of fistula formation after repeated laser conization (2). We cannot state that these conditions are contraindications for electrosurgical excision because of the rarity of these complications, but possibly the use of a smaller size of loop could have prevented this complication. LLETZ is an excellent technique for the treatment of CIN. Complications are usually few and mild, mainly minor bleeding and discomfort. These cases serve as a reminder that the LLETZ procedure, although simple and easily performed, can result in major complications. Patients with a distorted cervix, previous cervical conization or pelvic irradiation are at increased risk. Surgeons should be aware of these possibilities and their immediate identification is crucial to prevent further damage. It is suggested that in such cases one should use a smaller loop-wire for colposcopically oriented cervical tissue removal. A hysterectomy should be considered if the patient has completed her family planning. The authors wish to thank Mrs Gloria Ginzach and Mrs Marian Propp for their editorial and secretarial assistance.