Patient Sequelae and Accrued Health Care Costs from Intra-Abdominal/Pelvic Adhesions

Abstract

Objective: The purpose of this study was to review and compile the latest published data on the subject of postoperative peritoneal adhesions specific to the obstetric and gynecologic population, and examine its associated economic implications. Materials and Methods: This is a review of the published literature to identify studies on adhesions in obstetrics and gynecology that reported any of four outcomes of interest (hospital readmission [medical/surgical], small bowel obstruction, operating room time costs, and impact on subsequent surgical intervention). PubMed database was scanned for English-language references published between January 1995 and January 2011. Search terms included: peritoneal adhesions after gynecologic surgery, peritoneal adhesions after obstetric surgery, and cost analysis of peritoneal adhesions. Articles, conference abstracts, and professional medical society consensus statements were reviewed. References pertaining to the pediatric population (≤14 years of age), non-abdominal/pelvic location, or those discussing only molecular/pathophysiological adhesion development were excluded. Also excluded were publications relating to infertility or chronic pelvic pain, for a more detailed compilation relating to our four main categories. Results: A total of 122 PubMed materials were identified using the initial search strategy: “peritoneal adhesions after gynecologic surgery” n=86, “peritoneal adhesions after obstetric surgery” n=25, and “cost analysis of peritoneal adhesions” n=11. Conclusions: With the review of the current focused data, the importance of peritoneal adhesion prevention and future research is evident. At a time when the United States cesarean delivery rate approaches 1 of every 3 pregnancies, we must continually strive to reduce patient morbidity. (J GYNECOL SURG 28:1)

Introduction

The development of postoperative adhesions remains an almost inevitable consequence of abdominal and gynecologic (pelvic) surgery, appearing in 50%–95% of all patients. Early and late bowel obstruction, chronic abdominal pain, infertility, and complications in subsequent surgical intervention are the main clinical complications. Additionally, peritoneal adhesions directly increase socioeconomic costs and burden the health care industry.¹

The field of obstetrics and gynecology (ObGyn) currently performs the most common laparotomy in the world, cesarean delivery (CD). Today, with 4,000,000 births reported (on average) in the United states per year, and a current United States national cesarean delivery rate of 32%, ∼1,280,000 annual CDs occur in the country.²

In the United States, a steady upward trend in CD rates has existed over the past decade. According to the Centers for Disease Control and Prevention, CD rates have risen across all maternal age demographics, all ethnic/racial groups, as well as all gestational ages, resulting in a current national CD rate of 32%.² Never before in the United States' obstetric histories have CDs reached this all time high. According to a recently published projection of expected CD rates by 2010, extrapolation of trend data places the national CD rate at 50% by the year 2010.³ The result would be an estimated 2,000,000 CDs/year annually in the United States.

The surgical burden placed on ObGyn is not limited to CD. The discipline is also responsible for the second most common laparotomy in women, hysterectomy. Published incidence for the United States place hysterectomy performance at 600,000/year.⁴ Unfortunately, despite consensus options from the American College of Obstetricians and Gynecologists as well as the American Association of Gynecologic Laparoscopy, most of the hysterectomies performed in the United States are via the abdominal route (66%) by formal laparotomy.^4,5 The sequelae arising from these two most common surgical interventions in women are now being emphasized in the ObGyn peer review literature, specifically with respect to peritoneal adhesion formation.

As medical economics and the health care industry are continually steering toward reduced patient morbidity and cost containment, this article sought to review and compile the latest published data on the subject of postoperative peritoneal adhesions specific to the ObGyn population and examine their associated economic implications. Four main categories will be reviewed: hospital readmission (medical/surgical), small bowel obstruction (SBO), operating room time costs, and impact on subsequent surgical intervention.

Materials and Methods

A review of the published literature, to identify studies on adhesions in ObGyn that reported any of our four outcomes of interest, was performed. The PubMed database was searched for English-language references published between 1995 and January 2011. Search terms included: peritoneal adhesions after gynecologic surgery, peritoneal adhesions after obstetric surgery, and cost analysis of peritoneal adhesions. Articles, conference abstracts, and professional medical society consensus statements were reviewed. References pertaining to the pediatric population (≤14 years of age), non-abdominal/pelvic location, or those discussing only molecular/pathophysiological adhesion development were excluded. Additionally, it was decided to exclude publications relating to infertility or chronic pelvic pain, for a more detailed compilation relating to the four main categories.

Titles and abstracts were reviewed using explicit inclusion criteria to identify articles pertaining to the search objective. Letters and case reports were excluded. After title and abstract review, a full-text review was conducted and included all studies that reported outcomes of interest.

Results

Literature review

A total of 122 PubMed materials were identified using the initial search strategy: peritoneal adhesions after gynecologic surgery n=86, peritoneal adhesions after obstetric surgery n=25, and cost analysis of peritoneal adhesions n=11. This monograpgh represents the data summary of the 34 selected publications that met the inclusion criteria and underwent a full-text review.

Discussion

Scope of the problem

The incidence of peritoneal adhesion after ObGyn surgery has been well described. In a study by Brill et al., 360 women undergoing operative laparoscopy after a previous laparotomy were assessed for adhesions between the abdominal wall and the underlying omentum and bowel. Additionally, complications resulting directly from these adhesions were documented. Patients with prior midline incisions had significantly more adhesions (56.9%; 58 of 102) than did those with Pfannenstiel incisions (27.1%; 70 of 258). Patients with midline incisions performed for gynecologic indications had significantly more adhesions (42.1%; 109 of 259) than those with all types of incisions performed for obstetric indications (21.8%; 12 of 55). Adhesions to the bowel were significantly more frequent after midline incisions above the umbilicus (Table 1). Twenty-one women suffered direct injury to adherent omentum and bowel during the laparoscopic procedure.⁶

Table 1.

Peritoneal Adhesion Formation Following Laparotomy

Skin incision type	Adhesion frequency (%)	Adhesion location (omentum/bowel)
Pfannesnstiel	27 %	Omentum 87%
		Bowel 13%
Infraumbilical vertical	67 %	Omentum 83%
		Bowel 17%
Supraumbilical vertical	55 %	Omentum 60%
		Bowel 40%

Adapted from Brill et al.⁶

With the increased rate of CDs, the frequency of post-cesarean adhesions has come into the medical literature. In one retrospective study, adhesions of all grades were found in 46% of second cesarean births, 76% of third cesarean births, and 83% of fourth cesarean births.⁷ Similarly, Tulandi et al. documented adhesion frequencies of 24% of second cesarean births, 43% of third cesarean births, and 48% of fourth cesarean births.⁸ Percent differences between the two studies can be explained by the subjective grading scales used in each cohort. The percentage of moderate-to-severe adhesions in each cohort varied less because of the more reproducible classification of cohesive disease. Additionally, Nisenblat et al. compared 277 women undergoing three or more CDs to 491 women undergoing a second CD. Excessive blood loss (7.9% vs 3.3%; p<0.005), difficult delivery of the neonate (5.1% vs 0.2%; p<0.001), and dense adhesions (46.1% vs 25.6%; p<0.001) were significantly more common in the group of women undergoing three or more CDs, validating what practicing obstetricians have known for years.⁹ More recently, a case study highlighting the unique nature of the post-cesarean section uterine adhesion (fascia to anterior uterine surface) and its related sequlae has been published, reaffirming the increased risk of adhesions from CD.¹⁰

Hospital readmission

Since the initial report by Bryant describing patient mortality stemming from postoperative adhesive bowel obstruction,¹¹ the legitimacy of sequelae from peritoneal trauma has been well characterized. A published investigation of the epidemiology and clinical burden related to adhesions following gynecologic surgery has focused the attention of the ObGyn community. The analysis used the Scottish National Health Service Medical Record Linkage Database (SCAR) to follow a cohort of 8849 women undergoing open gynecologic surgery up to 1986. These patients were followed for all readmissions for potential adhesion-related disease in the subsequent 10 years.¹² Two hundred forty-five (4.5%) of 5433 readmissions following open gynecologic surgery were directly related to adhesions. Additionally, 34.5% of patients were readmitted, on average 1.9 times, for a problem potentially related to adhesions or for further intra-abdominal surgery that could be complicated by adhesions. Readmissions related to adhesions continued throughout the 10-year period of the study. The overall rate of readmission was 64.0/100 initial operations. For readmissions directly related to adhesions, the rate was 2.9/100 initial operations. Operations on the ovary had the highest adhesion-related readmission rate (7.5/100 initial operations), with an overall readmission rate of 106.4/100 initial operations. Of all readmissions, 16% were seen in the initial postoperative year, but readmissions continued steadily throughout the period of the study.¹² It was the conclusion of the authors that “post-operative adhesions have important consequences for patients, surgeons and the health care system. These results emphasize the need for more effective strategies to prevent adhesions.”

Others have reported a more surprising risk of direct adhesion-related hospital admission at 1:50 following open tubal or ovarian surgery and 1:80 following similar laparoscopic surgery.¹³ “This is considerably higher than the risks of complications normally discussed during the consent process including general anesthesia risks (1:100) and general complications such as pain, infection or bleeding (1:1000 to 1:500).”¹³

Therefore, adhesion-related complications are increasingly the subject of forensic and medicolegal debate. Medicolegal litigation resulting from complications secondary to postoperative adhesions may contribute to health care costs and clinician burden.

SBO

Published reports place SBO as one of the most dreaded complications of adhesion formation, with a rate of 50%–75% of all SBOs being related to postoperative adhesions.^14–16 Until recently, most of the published data arose from either general or colorectal surgery. The relationship between adhesion-related SBO and gynecologic operations helped shed light on the problem specific to women's health care. Al-Took et al. studied the records of all female patients with the diagnosis of SBO from 1989 to 1996. The cause of bowel obstruction, the type and technique of previous operations, and whether the parietal peritoneum was closed at the completion of the procedure or was left open were evaluated. Among 262 women, the most common cause of SBO was intra-abdominal adhesions (37.0%). Among the 92 women with adhesion-related SBO, 35 women (38%) had undergone a previous abdominal hysterectomy. The incidence of SBO after an abdominal hysterectomy was 16.3 per 1000 hysterectomies. The incidence of SBO after CD (5/10,000 CDs) was significantly less than after other abdominal operations. Among the 47 women who had undergone previous gynecologic surgery, adhesions were found between the small bowel and the pelvis in 14 (29.8%), and all were in women who had undergone a hysterectomy. In 33 others (70.2%) the adhesions were found between the previous abdominal incision and the intestine. The median interval between the initial operation and the SBO was 5.3 years. In their conclusion, the authors remind the reader that “the most common cause of small-bowel obstruction is postsurgical adhesions. Adhesion related small-bowel obstruction is commonly found after an abdominal hysterectomy. Bowel obstruction can occur many years after the initial abdominal surgery.”¹⁷

Compared with Al Took's previous study, published in 1999, the rate of adhesion-related SBO seems to be rising. In a recent review published from the Society of Maternal Fetal Medicine, the rate of bowel obstruction after CD was reported at 9 per 1000 after 3 CDs,¹⁸ compared with Al Took's rate of 0.5 per 1000.¹⁷ A recent publication (2010) assessed the rate of adhesion-related SBO at 2.2 per 1000. The authors concluded that “one of 360 CDs may lead to symptomatic adhesions or bowel obstruction requiring hospitalization or surgery. The public health implications of these post-CD complications should not be neglected.”¹⁹ The increase in prevalence of adhesion-related SBO may be a function of the rise in CD in the United States.

Additionally, Ivarsson et al. assessed the direct costs associated with bowel obstruction resulting from adhesions. In this prospective study, 57 Swedish patients ≥16 years of age who fulfilled the clinical and radiologic criteria of bowel obstruction were analyzed.²⁰ In 34 of the 57 patients (60%) bowel obstruction was caused by adhesions, and in all 34 the small bowel was obstructed (85% of all cases were SBO). Of the patients who required a hospital stay of >24 hours (n=42), 52% had adhesive obstruction, and 10 of these patients (45%) had to be operated on, 2 of them twice. Major complications occurred in 6 (60%) of the 10 patients requiring surgery, and 1 death was reported. The authors estimated that adhesive bowel obstruction may cause 2330 hospital admissions annually, which is associated with an estimated direct cost of ∼US $13,000,000.²⁰ This study was published in 1997, and may underestimate the current financial burden of adhesion-related SBO, because of the climbing rate of SBO and current cost considerations in 2011 compared to 1997.

Operative time considerations

Charges for most United States operating room services generally depend upon the complexity of the particular operation. By convention, there is an initial charge as well as a per minute charge while the operation is being performed. Therefore, delays in surgical completion resulting from adhesions may have economic ramifications for the health care industry and patient alike. This is, of course, in addition to the increased morbidity of excess time under anesthesia.

Operating room costs vary depending upon the hospital. Published rates range from $4.29 to $20.83 per minute.^21,22 However, these rates are lower than rates posted on the Internet by some hospitals. Cleveland Clinic has posted operating room charges ranging between $1769 and $3336 per 30 minute block,²³ whereas Ohio Health's charges range from $3981 to $7319 per 30 minute block.²⁴ Therefore, a more realistic estimate of operating room cost per minute may be anywhere from $59 to $234.

It is well known that CD-related adhesions contribute to longer delivery times and total operating times during subsequent CDs. Tulandi et al. reported skin incision to fetal delivery times of 8.9 minutes for a first CD, 10.7 minutes for a second CD, and 12.8 minutes for a third CD.⁸ Using a conservative estimate of $50 per minute for operating room time, this would translate into $385 for the first CD, and up to $530. Similarly, Morales et al. reported an 18-minute delay of a fourth CD as a result of adhesions,⁷ which would amount to an additional $900 of operating room costs assuming $50/hour.

In a study of time required to gain access to the abdomen to perform a planned procedure in patients with and without previous surgery, Beck et al. measured opening time (skin incision to retractor placement). A comparison of opening times between patients with and without previous abdominal operations was conducted. One hundred ninety-eight patients had abdominal operations, with 55% having had previous abdominal procedures. Patients who had had prior surgery required a mean of 21 minutes to open their abdomens, whereas patients who had not had prior surgery required a mean of 6 minutes (p<0.01). The median times were 17 and 6 minutes, respectively. Eighty-three percent of patients who had had prior surgery had adhesions, whereas only 7 percent of patients had adhesions on their initial operation. Patients who had had prior surgery also had higher grade adhesions (p<0.001). Irrespective of previous surgery, comparing patients with adhesions with those without, patients with adhesions required a mean of 22 minutes to open, whereas the lack of adhesions resulted in a mean opening time of 6 minutes. It was concluded that previous surgery and the presence of adhesions add significant time to opening the abdomen.²⁵ Although not specific to ObGyn, the content in the study is applicable. Applying the same $50 per minute of operating room time, the presence of adhesions would account for an additional $750.

Impact on subsequent surgical intervention

The hindrance/complexity that intra-abdominal adhesions contribute to during subsequent surgical intervention is well published. With regard to CD, it has been referenced previously in this article that delays in fetal delivery/extraction parallel the number of prior CDs.⁷ This has a remarkable, and possibly devastating, effect in the setting of an urgent ("stat") CD. Recently, Wang et al. described the operative outcomes of laparoscopic-assisted vaginal hysterectomy in patients with a prior history of CD. As the number of CDs rose, so did the risk of incidental cystotomy, peaking at 21% after 3 CDs. Additionally, 10% of surgeons aborted the laparoscopic procedure in favor of laparotomy.²⁶ These findings supported earlier work by Boukerrou et al., which also found higher patient morbidity with increased CDs. This study compared the cumulative frequency of complications in patients undergoing hysterectomy with a previous history of CD to a group without a history of CD. There were more perioperative complications in the group with prior CD (13 of 71; 18.3%) than in the group without (24 of 670; 3.6%). Findings showed that the frequency of hemorrhage and the number of injuries to the bladder and intestines were higher in patients with a history of CDs. There was a significant difference between the cumulative frequencies of complications in the two populations of patients in favor of the subgroup without past cesarean scarring (p<0.0001) caused by adhesive syndromes.²⁷

Visceral injury at repeat CD caused from adhesions is also well characterized.^28–30 In a recent 25-year review of >7000 CDs, Rahman and colleagues found significantly more intra-operative bladder injuries caused directly by adhesion presence in women with prior CD or prior abdominopelvic surgery.³¹ Again, such injury not only impacts morbidity, but also health care costs to the system overall.

Adhesion prevention: Perspectives on surgical technique and adhesion barriers

Surgeons should incorporate several techniques to reduce the risk of adhesions. Avoiding excessive tissue handling and trauma and minimizing foreign body reactions—which includes exposure to medical glove powder—are two essential measures. To prevent tissue desiccation, clinicians should use intra-abdominal electrocautery judiciously. Electrocautery produces eschar, which is carbon debris that causes peritoneal injury. Similarly, one should avoid tissue ischemia by use of nontraumatic clamps, achieve hemostasis, irrigate the surgical field, use nonreactive suture material, and apply a barrier product approved by the United States Food and Drug Administration (FDA). Good surgical technique should include all these measures.^32,33 In a recent 3-year retrospective review of repeat CD, Chapa et al. described the clinical utility of an absorbable barrier (Oxidized Regenerated Cellulose, Interceed, Gynecare; Somerville NJ) in reducing the incidence as well as severity of adhesions between the uterus and adjacent structures. Logistic regression was used to exclude potential confounding variables. Results showed that fetal extraction times were statistically different between the barrier and no-barrier group, favoring barrier use.³⁴

A recent Cochrane Review of adhesion-prevention methods following gynecologic surgery reviewed 16 randomized clinical trials, and found that Interceed reduces the incidence of adhesion formation following laparoscopy and laparotomy. There was no evidence of effectiveness of Seprafilm and Fibrin sheet in preventing adhesion formation.³⁵ Theorized reasons for the differences in effectiveness of these adhesion barriers stem from the residence time after application of each, with oxidized regenerated cellulose maintaining tissue separation through adhesiogenesis and organization.³⁶ The difficult handling and placement of hyaluronic acid and carboxymethylcellulose (Seprafilm™; Genzyme, Cambridge, MA) is also theorized to be responsible for the difference in clinical effectiveness (level C opinion).

Cost effectiveness of antiadhesion agents

In 2007, a consensus position was published on behalf of the Expert Adhesions Working Party of the European Society of Gynaecological Endoscopy (ESGE), representing the collective views of 35 gynecologists with a recognized interest in adhesions.³⁷ This publication recognized that in considering use of an adhesion-reduction agent, factors to be taken into consideration included not only safety, ease of use, and clinical efficacy, but also cost effectiveness. Although it may be difficult to evaluate the impact of an antiadhesion agent on subsequent clinical outcomes³⁷ cost effectiveness of these agents can be modeled. Epidemiologic data from the SCAR study⁷ have been used to model the cumulative costs over time of adhesion-related hospital readmissions following surgery with or without the use of an adhesion-reduction agent, and have recently been updated with the costs of inflation. This model is helpful in understanding the value of different adhesion-reduction agents and suggests that a suitably priced and effective agent can result in overall cost savings to a health care system. For example, agents costing ∼€130 ($188.00 current United States equivalent)^* only need to demonstrate a 26% reduction in adhesion-related readmissions 3 years after surgery to return their costs, whereas agents costing ∼€300 ($433.00 current United States equivalent)* per operation would need to demonstrate at least a 60% reduction in adhesion-related readmissions 3 years after surgery to return the costs of their investment.”³⁸

Conclusions

Postoperative adhesions clearly have an important impact on the successful clinical outcome of surgery and pose an important cost burden. This article serves as a medical peer review summary and update on the pathologic sequelae of postoperative adhesions, specific to the ObGyn population. This article is meant to review the main clinical issues facing both the practicing physician and the health care industry. It is important to note that other adhesive sequelae (e.g., infertility, pelvic pain, absenteeism from work) in the female population were not analyzed herein. Therefore, the true economic implications of this pathologic entity may be grossly underestimated. In 2007, a statistical model was presented using data from The Healthcare Cost & Utilization Project's (HCUP) Nationwide Inpatient Sample (NIS) Database to estimate inpatient costs attributable to adhesiolysis, stratified by type of procedure and by body system for the year 2005. The total inpatient costs for adhesiolysis-related hospitalizations were $2.25 billion. Specific cost breakdown included:

• Hospitalizations primarily resulting from adhesiolysis totaled $1.35 billion, and hospitalizations secondary to adhesiolysis totaled $902 million.

• 69% ($622 million) of all secondary adhesiolysis expenditures were related to procedures for the digestive system.

• Roughly 25% ($220 million) of the expenditures were related to procedures for the female reproductive system.

• The majority of hospitalizations were related to the female reproductive system across the 3 study years.

• 20% of hospitalizations related to the female reproductive system were attributable to adhesiolysis.

With the review of the current focused data, the importance of peritoneal adhesion prevention and future research is evident. At a time when the CD rate in the United States approaches 1 out of every 3 pregnancies, we must continually strive to reduce patient morbidity. Although certain sequelae from multiple CDs are not modifiable (placenta previa, placenta accreta), the formation of peritoneal adhesions can be modified and reduced. Although certain laparotomies are unavoidable for medically indicated diagnoses, peritoneal adhesions do not have to be.

Footnotes

Disclosure Statement

H.O.C. serves as a medical consultant for Ethicon Gynecare, the manufacturer of Gynecare Interceed. The views/opinions in this article are not representative of any corporation/industry. No monetary remuneration was given for the production, organization, or publication of this article.

*

Author H.O.C. monetary conversion.

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