Lateral internal sphincterotomy together with haemorrhoidectomy for treatment of haemorrhoids: a randomised prospective study.

Objective: To investigate anorectal manometric findings in patients with haemorrhoids and to evaluate the clinical effects and physiological consequences of adding a lateral internal sphincterotomy (LIS) to haemorrhoidectomy.

Design: Randomised prospective study.

Setting: Teaching hospital, Naples.

Patients: 48 consecutive patients with prolapsed piles who had anorectal manometry; 10 healthy volunteers served as controls.

Interventions: Resting and squeeze pressures, sphincter length and rectoanal inhibitory reflex were recorded. 6 patients were excluded because anal pressures were not raised, so 42 patients were randomised. 22 patients had haemorrhoidectomy plus LIS; and 20 had haemorrhoidectomy alone.

Main outcome measures: Morbidity, continence, and anorectal manometry.

Results: Sphincter anomalies were found in 87.5% (n = 42) of patients. Haemorrhoidectomy alone did not affect anal pressures, which returned to the normal ranges after sphincterotomy. Those who had LIS did better postoperatively than those who had did not. 4 patients who did not have a sphincterotomy developed anal strictures. No patient who had LIS developed incontinence of faeces.

Conclusions: High anal pressures are common in patients with haemorrhoids suggesting that they may have a pathogenetic role; anorectal manometry is useful in the investigation of anal pressure patterns; and when indicated, lateral sphincterotomy avoids pain, urinary retention, and stenosis, and is safe.