Thursday, April 13, 2006

Adhesions: A Clinical Problemby Colin Brown

Postsurgical adhesions have long been implicated in iatrogenic intestinal obstruction. Epidemiological studies have documented the widespread impact of intraperitoneal (IP) adhesions. Incidence is underestimated because adhesion formation can only be assessed by reopening the abdomen, and also because symptoms may take many years to manifest.
Peritoneal adhesions occur in 60% _ 90% of patients undergoing major gynecologic surgery. Adhesion-related complications include infertility, chronic pelvic pain, ureteral obstruction, voiding dysfunction, and intestinal obstruction (incidence of 0.3% _ 5% after surgery for benign conditions). Adhesions can impair effectiveness of IP ovarian cancer treatments. Intraperitoneal chemotherapy, itself, induces peritoneal sclerosis and adhesion formation — a cisplatin-based study (UCSD Cancer Center) found a 6% incidence of small bowel obstruction.
Studies in the USA and the UK assessed the incidence and health care costs of general postsurgical adhesion-related bowel obstruction and adhesiolysis. A retrospective cohort study used patient-specific Health Care Financing Administration data to evaluate a random sample of Medicare patients undergoing surgery in 1993: 18,912 had open colorectal or general surgery. A 2-year follow-up showed outcomes of hospitalizations with obstruction (18.6% _ 25.1%), adhesiolysis for obstruction (2.6% _ 5.6%), and/or additional open colorectal or general surgery (10.3% _ 23.8%). Hospitalization costs in the first year alone were an estimated US$217.1 million.
Data from the National Hospital Discharge Survey and Medicare records were used to estimate total annual costs of abdominal adhesiolysis in the USA in 1988 and 1994. Hospitalizations involving adhesiolysis totalled 281,982 and 303,836 in 1988 and 1994, respectively and, including surgeon fees, total expenditures were around $1.18 and $1.3 billion.
Data from Westminster Hospital (UK) included a 4-year prospective study of 210 patients undergoing open laparotomy following previous abdominal surgery. Overall incidence of adhesions (94.3%, with 93% due to surgery) contrasted with 10.4% in 115 first-time laparotomy patients. Over a 25-year period, peritoneal adhesions accounted for 0.9% of 28,297 adult surgical admissions, 3.3% of 4,502 laparotomies, and 28.8% of 514 bowel obstructions. In a 13-year prospective study, 3.2% of 2,708 laparotomies showed adhesive intestinal obstruction; 93% were postsurgical. About 21% presented within 1 month of initial surgery, and 39% within a year, but 20% of postsurgical adhesive obstructions took more than 10 years to develop.
The Scottish National Health Service medical record linkage database was used to identify 29,790 patients undergoing open abdominal or pelvic surgery in 1986, who had no record of such surgery in the preceding 5 years. In a 10-year follow-up, 34.6% were readmitted a mean of 2.1 times for adhesion-related disorders or surgery that might be complicated by IP adhesions. About 22% of outcome readmissions occurred within 1 year of initial surgery, but they continued steadily throughout the decade. The rate of adhesion-related admissions in 1 year (1994) matched rates for hip replacement, coronary artery bypass grafts, appendectomies, and hemorrhoid surgery.
In 1992, a survey of 362 general surgeons showed annual totals per surgeon of 3 _ 4 surgeries for adhesive obstruction, 7 _ 8 conservative treatments, and 3 cases of adhesion-related complications in unrelated abdominal surgery. Estimated UK totals suggest that, in general surgery alone, adhesions may impact on 18,000 cases annually, with a mean hospitalization requirement of more than 2 weeks.
Epidemiological evidence demonstrates an almost inevitable link between abdominal surgery and peritoneal adhesions, with a lifetime risk for the patient of complications such as bowel obstruction. Surgical adhesiolysis is extremely prone to reformation of adhesions with a recurrence of symptoms. This serious health care burden can only be reduced by improved preventative measures.
Adhesions: A Clinical Problemby Colin Brown

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