April's paper of the month looks at perineal wound healing after abdominoperineal resection for rectal cancer: a retrospective cohort study.
Hákonarson A, Algethami N, Lydrup ML, Buchwald P. Int J Colorectal Dis 2022 Apr 8. doi: 10.1007/s00384-022-04141-7.
Online ahead of print.
What is known about the subject?
Abdominoperineal resection (APR) was introduced by William Ernest Miles in 1908, for the treatment of rectal cancer and still has a role in the surgical treatment of low rectal cancer. However, with improved surgical techniques and increased knowledge of the pathophysiology of rectal cancer, APR rates have decreased. Following APR, wound healing in the perineum is associated with a high risk of complications. Bacterial contamination of the perineum, decreased circulation in the perineal tissue, dead space in the pelvis after rectal excision and a large proportion of patients receiving neoadjuvant radiotherapy may contribute to an increased risk of delayed wound healing and eventually wound complications. The severity of complications varies greatly, but often cause significant morbidity ranging from increased hospital stay and frequent wound care after discharge, or even long-standing problems such as perineal sinus and fistulas, chronic pain, and risk for developing a perineal hernia. This study specifically aimed at investigating the number of patients with delayed wound healing after APR for rectal cancers, to identify risk factors, and describe treatment.
What the study adds?
This retrospective cohort study of consecutive patients used prospectively collected data from the Swedish Colorectal Cancer Registry (SCRCR) was performed at Skåne University Hospital including patients treated 2013-2018. Medical charts were reviewed for data validation and collection of variables not available in SCRCR. Delayed healing was defined as non-healed perineal wound 30 days postoperatively. Patients undergoing extralevator APR requiring reconstruction were excluded. 162 patients were included, of whom 114 underwent standard APR (sAPR) and 48 patients intersphincteric APR (isAPR) . In the total population, 69% (111/162) were male, with median age 71 (26-87) years. The overall healing rate was 52% (85/162); 44% (50/114) in sAPR vs 73% (35/48) in isAPR (p<0.001). Risk factors for impaired healing after multivariable analysis were BMI > 30 (OR 7.0; CI 95% 1.8-26.2, P=0.004), reoperation (OR 7.9; CI 95% 1.6-39.8, P=0.013), neoadjuvant radiotherapy (OR 5.2; CI 95% 1.02-25.1, P =0.047) and sAPR (OR 2.6; CI 95% 1.05-6.41, P=0.038). Eight percent (13/162) of patients required an intervention (Clavien-Dindo ≥3).
Limitations of the study included it being single centre and non-availability of some important data such as preoperative albumin and precise radiation field. However, the strengths of the study were a meticulous review of medical charts, a standardized perioperative protocol and a relatively long follow-up time resulting in a complete data set.
Implications for colorectal practice
In this contemporary rectal cancer patient cohort, more than 50 percent of patients subjected to APR had an unhealed perineal wound 30 days after surgery. Neoadjuvant radiotherapy, obesity, and early reoperations were risk factors for delayed healing. As expected, sAPR was associated with more compromised perineal wound healing than isAPR. However, most patients could be treated conservatively, with only eight percent of patients requiring surgical intervention.
The high rate of infectious complications after APR has been observed previously. In Skövde, Sweden, a nine-step concept was created to address this, with a dramatic drop in postoperative infections. This includes using collagen implants impregnated with Gentamycin (such as Gentafleeceä or Collatampä). This concept was adopted at Skåne University Hospital, but interestingly, did not appear to signifanctly prevent delayed perineal wound healing (p=0.54). However, there was a tendency for less risk for complications in patients where rectal washout was performed intraoperatively. Therefore, despite rectal washout failing to influence oncological outcomes in APR, rectal washout may impact perineal wound healing by reducing infectious contamination. Further studies aiming at interventions reducing delayed perineal wound healing after APR are warranted.