Use a prophylactic antibiotic with extended coverage for anaerobes prior to or during your anal sphincter repair
Many experts recommend one dose of a prophylactic antibiotic prior to, or during, OASIS repair in order to reduce the risk of wound complications. In a trial 147 women with OASIS were randomly assigned to receive one dose of a second-generation cephalosporin (cefotetan or cefoxitin) with extended anaerobic coverage or a placebo just before repair of the laceration.9 At 2 weeks postpartum, perineal wound complications were significantly lower in women receiving one dose of prophylactic antibiotic with extended anaerobe coverage compared with placebo—8.2% and 24.1%, respectively (P = .037). Additionally, at 2 weeks postpartum, purulent wound discharge was significantly lower in women receiving antibiotic versus placebo, 4% and 17%, respectively (P = .036). Experts writing for the Society of Obstetricians and Gynaecologists of Canada also recommend one dose of cefotetan or cefoxitin.10 Extended anaerobic coverage also can be achieved by administering a single dose of BOTH cefazolin 2 g by intravenous (IV) infusion PLUS metronidazole 500 mg by IV infusion or oral medication.11 For women with severe penicillin allergy, a recommended regimen is gentamicin 5 mg/kg plus clindamycin 900 mg by IV infusion.11 There is evidence that for colorectal or hysterectomy surgery, expanding prophylactic antibiotic coverage of anaerobes with cefazolin PLUS metronidazole significantly reduces postoperative surgical site infection.12,13 Following an OASIS repair, wound breakdown is a catastrophic problem that may take many months to resolve. Administration of a prophylactic antibiotic with extended coverage of anaerobes may help to prevent wound breakdown.
Prioritize identifying and separately repairing the internal anal sphincter
The internal anal sphincter is a smooth muscle that runs along the outside of the rectal wall and thickens into a sphincter toward the anal canal. The internal anal sphincter is thin and grey-white in appearance, like a veil. By contrast, the external anal sphincter is a thick band of red striated muscle tissue. In one study of 3,333 primiparous women with OASIS, an internal anal sphincter injury was detected in 33% of cases.14 In this large cohort, the rate of internal anal sphincter injury with a 3A tear, a 3B tear, a complete tear of the external sphincter and a 4th-degree perineal tear was 22%, 23%, 42%, and 71%, respectively. The internal anal sphincter is important for maintaining rectal continence and is estimated to contribute 50% to 85% of resting anal tone.15 If injury to the internal anal sphincter is detected at a birth with an OASIS, it is important to separately repair the internal anal sphincter to reduce the risk of postpartum rectal incontinence.16
Polyglactin 910 vs Polydioxanone (PDS) Suture—Is PDS the winner?
Polyglactin 910 (Vicryl) is a braided suture that is absorbed within 56 to 70 days. Polydioxanone suture is a long-lasting monofilament suture that is absorbed within 200 days. Many colorectal surgeons and urogynecologists prefer PDS suture for the repair of both the internal and external anal sphincters.16 Authors of one randomized trial of OASIS repair with Vicryl or PDS suture did not report significant differences in most clinical outcomes.17 However, in this study, anal endosonographic imaging of the internal and external anal sphincter demonstrated more internal sphincter defects but not external sphincter defects when the repair was performed with Vicryl rather than PDS. The investigators concluded that comprehensive training of the surgeon, not choice of suture, is probably the most important factor in achieving a good OASIS repair. However, because many subspecialists favor PDS suture for sphincter repair, specialists in obstetrics and gynecology should consider this option.
Continue to: Can your patient access early secondary repair if they develop a perineal laceration wound breakdown?