Complications of Products Developed to Prevent Complications
Abstract & Commentary
By Robert L. Coleman, MD, Professor, University of Texas; M.D. Anderson Cancer Center, Houston, is Associate Editor for OB/GYN Clinical Alert.
Dr. Coleman reports no financial relationship to this field of study.
Synopsis: HA-CMC barrier placement at the time of optimal cytoreduction was not associated with increased postoperative complications, but may be associated with an increased incidence of pelvic abscess.
Source: Krill LS, et al. Analysis of postoperative complications associated with the use of anti-adhesion sodium hyaluronate-carboxymethylcellulose (HA-CMC) barrier after cytoreductive surgery for ovarian, fallopian tube and peritoneal cancers. Gynecol Oncol 2010 Dec 7; Epub ahead of print.
Intraoperative placement of adhesion barriers has been a long-practiced adjuvant to major abdominal/pelvic surgery in an attempt to reduce postoperative complications such as bowel obstruction and infertility. Most available evidence suggests HA-CMC barriers are safe and effective in reducing postoperative adhesions, particularly in patients undergoing bowel surgery for non-cancer indications. However, the nature of ovarian cytoreduction involves performing many of these same types of procedures in potentially riskier and more compromised patients. The authors of the current retrospective report investigated whether patients undergoing optimal cytoreduction experienced higher postoperative morbidity when HA-CMC barriers were placed. Over a 14-year period, 375 patients underwent optimal surgical cytoreduction, in whom HA-CMC barriers were placed in 168 (45%). Institutional practice patterns left placement to the discretion of the primary surgeon; however, placement was not utilized in those in whom a suboptimal resection was achieved. The sheets were placed more often in patients in whom complete cytoreduction (no visible postoperative residuum) was achieved.
Univariate analysis of procedures performed demonstrated that HA-CMC barriers were utilized more frequently in patients undergoing hysterectomy, rectosigmoid resection, splenectomy, nodal dissection, diaphragm stripping, and placement of a pelvic drain. Despite these variances, major morbidity was similar between the two cohorts; pelvic abscess, however, was observed in 12% of patients with HA-CMC barriers vs 5% in those without (P < 0.01). Independent factors associated with pelvic abscess formation following HA-CMC barrier use were performance of a hysterectomy and primary (vs secondary) cytoreduction. Interestingly, placement of a pelvic drain was independently associated with risk of pelvic abscess (odds ratio [OR], 3.42; P = 0.04) and was accentuated by use of HA-CMC barriers (OR, 10.1; P = 0.005); however, use of HA-CMC barriers was only marginally associated with pelvic abscess risk (OR, 2.7; 95% confidence interval, 1.00-5.82; P = 0.05). The authors concluded that their data support others in the literature, but suggested that in their more homogenous population HA-CMC barriers may be associated with an increased risk of pelvic abscess.
The quest to prevent adhesions is driven by the morbidity observed when they do occur. Even though there may be no overt morbidity following the index surgical procedure, reoperation, which occurs frequently in patients with ovarian malignancy, can be hazardous, particularly if intraperitoneal chemotherapy has been administered. Other frequent events following aggressive cytoreduction, such as infection, hematoma, ileus, wound complications, and lymphocele, add to the potential for "abdominal catastrophe" when subsequent exploration is indicated. Since secondary cytoreduction for recurrent disease and surgical exploration for complications due to progressive disease are not uncommon, anything to reduce competing factors exacerbating an already tenuous situation is welcomed.
The current report draws attention to a potential complication that can indeed promote that which we sought to avoid, adhesions. While the literature to support the safety of HA-CMC barrier use is fairly consistent, their use in gynecologic oncology patients has been associated with an increase in postoperative fluid collections. This concern is very difficult to attribute solely to the barriers, as pelvic peritoneal stripping, ascites, and use of blood hemostatics/coagulants intraoperatively all contribute to these "anomalies" on postoperative imaging. However, in the current trial all of the events recorded as abscesses were confirmed infected by clinical criteria and/or microbiology assessment. In the package insert for this product, abscess is listed to be about 4 times higher (8% vs 2%) in patients randomized to HA-CMC while undergoing colectomy/ileal pouch anastomosis. However, power to detect a difference in that study (as in the current trial) was insufficient to adequately assess this risk. The current trials' retrospective nature, as well as its lack of description of where the sheets were placed, potential imbalance of patient comorbidities, and lack of consistent criteria for percutaneous assessment limit definitive interpretation. However, the hypothesis that pelvic drain use may augment pelvic abscess formation when HA-CMC barriers are used should be addressed in future study, particularly since these drains are often placed to combat hematoma formation or complications from anastamotic leak.