Role of rectal biopsy in predicting response to intrasphincteric botulinum toxin injection for obstructive symptoms after a pullthrough operation.

OBJECTIVE: Our aim was to correlate the pathological results and clinical response in patients who underwent botulinum toxin (BT) injection for obstructive symptoms (OS) after a pullthrough operation for Hirschsprung's disease (HD). METHODS: Between August 2002 and February 2006, 16 of 107 HD patients (15%) were referred with persistent OS after pull-through (PT) operation in this center. They underwent rectal biopsy and BT injection in the internal sphincter. Their responses to BT injection were evaluated by the constipation score before, and at 1, 3 and 8 months after the injection, and anorectal manometry (ARM) before and at 2 weeks, and 1 and 8 months after the injection. The association between response to BT and acetylcholinesterase (AChE) staining of rectal biopsy was also assessed. RESULTS: Fourteen of 16 patients (87%) had improvement in bowel function after 2 weeks, and two patients did not respond at all. Six of the 14 patients with early response had recurrence of symptoms after 2-3 months. Eight patients with normal ganglia and negative AChE had good response with no recurrence on follow-up. However, 4 of 6 recurrences were neurogenic dysfunctions and 2 were intestinal neuronal dysplasia (2-4+AChE). Two patients with no response had an aganglionic segment (4+AChE). Four of 6 patients with recurrence showed improvement with BT re-injection and only 2 did not improve. CONCLUSION: A higher degree of AChE staining is associated with lack of response to BT injection. This is also a test for predicting the severity of neurogenic dysfunction in the intestinal wall.

Comparison of botulinium toxin injection and posterior anorectal myectomy in treatment of internal anal sphincter achalasia.

OBJECTIVE: We compared the efficacy of intra-sphincteric botulinum toxin (BT) injection and posterior anorectal myectomy (PARM) for the treatment of internal anal sphincter achalasia (IASA). METHODS: Twenty eight of 120 patients (23%) with chronic constipation, who were referred to our clinic from September 2005 to December 2006, were evaluated. Patients had an absence of rectoanal inhibitory reflex on anorectal manometry (ARM) and showed no transitional region on barium enema. Fourteen patients each underwent rectal biopsy, and were treated with either intrasphincteric BT injection (Group I) or PARM (Group II). Nine patients were excluded because of absent ganglion cells on histology or positive acetylcholinesterase staining (AChE). The remaining 19 patients were followed up. All patients underwent ARM and constipation severity score (CSS) assessment 2 weeks before, and 1 and 6 months after the treatment. Patients were followed up telephonically at 12 months after treatment. RESULTS: Clinically good response was seen after 12 months in 3 patients each in Groups I and II. The median values of resting rectal pressure in Group I before and 6 months after BT injection were 60 mmHg and 40 mmHg (p< 0.0001), respectively, while in Group II the corresponding values were 60 mmHg and 45 mmHg (p< 0.0001), respectively. Compared to pre-treatment, median CSS improved in both Group I (14 to 13) and Group II (16 to 14) at 6 months after treatment (p< 0.0001 for both). However, there was no difference in resting rectal pressure and CSS between the groups. Three patients in Group II developed local abscess, postoperatively. CONCLUSIONS: BT injection has a similar efficacy as compared with PARM for the treatment of IASA, is less invasive and, is also associated with fewer complications.