Injection of Botulinum A toxin (Botox®) into the levator ani muscle is a treatment modality that can be offered to patients with obstructed defecation syndrome (ODS) secondary to dyssnergic defecation and rectal pain associated with levator spam.   Paradoxical contraction of pelvic floor muscles and inabilitity to relaxation the pelvic floor are among the most frequently reported pathophysiological mechanisms occurring in ODS  and levator ani syndrome(LAS).   Botox causes temporary chemodenervation of the injected muscles resulting in relaxation.

Hypothesis: Botox®) injections improve symptoms of levator spasm and can be safely repeated even at a higher dose
 
Aim: To evaluate current clinical practice injecting Botox® for ODS and LAS  at a single institution.

Patients treated by 2 surgeons between January 2011 and December 2016 were selected from an IRB approved database using CPT code 46505 for Botox injections then specifically selected through ICD-9 codes of 564.6 (anal spasm)  and 564.02 (outlet dysfunction constipation). The electronic medical records of these patients were reviewed. Data included demographics, preoperative symptoms, investigations, intra-operative variables, 30-day complication rates and follow up. 
Descriptive statistics were computed for all variables of interest. They are presented as means for continuous factors, and frequencies for categorical factors.

Outcomes : Symptom relief and complications

51 patients (34 female) with a mean age of 48.8 years were evaluated. 26 (51%) presented with ODS and 25 (49%) with LAS. 35 patients underwent anorectal manometry. The abnormal findings were paradoxical contractions in 45.7% (16/35), balloon not expelled in 45.7% (16/35), abnormal volume studies in 31.4% (11/35) and high resting pressure in 14.3 % (5/35). All paradoxical contraction reports matched the inability to expel the balloon.  Additional diagnostic studies included: defecography (n=24), and colonic transit study (n=13). Defecography finding included rectocele 73.7% (14/19), difficulties or inability to initiate evacuation 15.8% (3/19), rectal intussusception 5.3% (1/19). 
Pelvic floor physical therapy was recommended for all patients either prior to or after Botox® injection. 23/51 patients underwent physical therapy, 14/26 (53.8%). patients with ODS received physical therapy prior to Botox® 
There were a total of 101 procedures in 51 patients performed over the study time period. 29 patients had a single procedure and 22 had multiple procedures (range 2 and 7). Botox 200 IU was the dose of choice in 67.7% procedures (67/101) and 100 IU was used in 23.2% for patients with lower sphincter tone or for patients with preoperative concerns about fecal urgency or leakage.  Kenalog  was used in 76 (75%).   
There were no significant complications.  Perianal bruising, mild bleeding, mild anal pain, and increased spasm was anecdotley reported   There were no episode of long-term incontinence reported. Overall, 22/51 (43.1%) reported improvement. 12/26 (46.1%) ODS patients reported better evacuation while 10/25 (40%) LAS patients reported improvements. Patients having a single procedure reported improvement in (44%) 11/25. Patients having multiple procedures reported improvement in 61.1% (11/18).

Paradoxical contractions are a common finding in patients with ODS. This is directly connected to the inability to evacuate stool. Other abnormal defecography results may co-exist but unless they cause mechanical obstruction they can be treated with symptomatic  treatment.
Botox injections in a higher dose was used safely without a risk of incontinence. The relief of symptoms in ODS is not sustained and many treatments as well as different modalities may be needed. In patients with no surgical option this may be their only option

In patients with Levator Ani syndrome the risk of incontinence is more than ODs however only one patient had temporary incontinence while relief of symptoms was in about 40 % of patients. This symptom has very few options and almost no surgical options.

Multiple injection may achieve sustained relief.

High doses of Botox® injections into the levators can be safely given and  improve ODS and levator spasm.  Repeat injections in patients who have relief of symptoms may be necessary to sustain results.

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