Use of hydrogen peroxide to identify internal opening of anal fistula and perianal abscess

Anal fistula: Intraoperative difficulties and unexpected findings

Anal fistula surgery is a commonly performed procedure. The diverse anatomy of anal fistulae and their proximity to anal sphincters make accurate preoperative diagnosis essential to avoid recurrence and fecal incontinence. Despite the fact that proper preoperative diagnosis can be reached in the majority of patients by simple clinical examination, endoanal ultrasound or magnetic resonance imaging, on many occasions, unexpected findings can be encountered during surgery that can make the operation difficult and correct decision-making crucial. In this article we discuss the difficulties and unexpected findings that can be encountered during anal fistula surgery and how to overcome them.

Can ileal pouch anal anastomosis be used in Crohn's disease?

Restorative proctocolectomy with IPAA is now accepted as the standard of care in most patients with a diagnosis of mucosal ulcerative or IndC requiring surgery. In patients with Crohn's colitis needing intervention, proctocolectomy with end ileostomy or subtotal colectomy with ileorectal anastomosis is still the treatment of choice. In the authors' institution they consider performing an ileal pouch for a diagnosis of Crohn's colitis requiring rectal resection provided there is no existing or previous evidence of perianal or small bowel CD. They only perform this in a well-motivated patient who understands the potential sequelae, including an increased incidence of adverse effects and reduced functional outcome, if they develop CD of the pouch. A significant amount of time must be allocated to the patient and their family when counseling them with regards to the potential surgical options and outcomes associated with each. The development of CD of the pouch is associated with a considerable pouch failure rate requiring pouch excision or indefinite ileostomy formation. It does not always herald disaster, however, and a large percentage of patients can be salvaged using a combination of medical and surgical therapy. In this patient group the maintenance of intestinal continuity and avoidance of an ostomy is often the most important factor in their perception toward quality of life. The search for a serologic or genetic marker that will predict disease outcome in this select patient group and thereby direct surgical decision making should continue. It is recommended that in the presence of Crohn's colitis the decision to perform an ileal pouch should only be made in a tertiary center under the care of gastroenterologists, histopathologists, and colorectal surgeons with experience in the management of these complex cases.

Venous oxygen embolism produced by injection of hydrogen peroxide into an enterocutaneous fistula

We report a venous oxygen embolism that occurred in a 66-yr-old man after 60 mL of 3% hydrogen peroxide was injected into a perianal fistula intraoperatively to locate its internal opening. The diagnosis was made after detecting hypoxemia, decreased end-tidal carbon dioxide tension, systemic hypotension, increased central venous pressure, and a new heart murmur. The patient recovered quickly and had no long-term sequelae. Oxygen embolism is a potentially fatal complication that can develop when hydrogen peroxide is used near venous spaces, and clinicians should be aware of the potential dangers when using this seemingly innocuous chemical.

Anal fistula

Anal fistula is a common cause of chronic irritation to both patients and surgeons. Treatment failure rates may be decreased by a good appreciation of normal anorectal anatomy and fistula pathoanatomy, as well as a wide and practical knowledge of the possible treatment regimens. The various treatment options available for acute abscesses as well as simple and complex anal fistulae are presented and discussed. Identification of the patient at risk of postoperative anal incontinence or of the difficult or high fistula may allow treatment in a specialized proctology unit.

Insights gained from the management of problematical anal fistulae at St. Mark's Hospital, 1984-88

Twenty-four (3.6 percent) patients with problematical anal fistulae out of 671 with anal fistulae were analysed to assess the reasons for their recurrences and ultimate outcome. Thirteen patients (group A) had recurrent fistulae despite two definitive attempts at surgery at this hospital (median number of previous procedures before referral to this hospital was two, range 0-7; median number of definitive procedures at this hospital was three, range 3-4). In five of these patients, the reason for recurrence was missed primary (four cases) or secondary tracks (one case) at earlier operations. Five patients required multiple operations related to the use of setons. Eleven other patients (group B) required colostomy construction, eight because of severe perianal sepsis, two because of complex fistulae, and one for postrectal dermoid. Fistula healing occurred ultimately in all patients in group A after a median of 14 months (range 4-38 months). In group B, fistula healing occurred in eight patients after a median of 7.5 months (range 2-55 months) after colostomy construction. Only one patient has had a proctectomy, and five still have their colostomy. Of the other 18 patients, continence is normal in 14, there is mucus leakage in two, flatus incontinence in one and faecal incontinence in one. In conclusion, persistent attempts to resolve anal fistulae in difficult cases are frequently successful in the long term and result in good continence.