Averting adhesions: Surgical techniques and tools

In a randomized trial, ePTFE decreased postmyomectomy and pelvic sidewall adhesions.^8,9 In our experience, this is the most effective adhesion-reducing substance available. It is not widely used, however, because it is nonabsorbable and has to be fixed to the tissue.

Combined hyaluronic acid (HA) and carboxymethylcellulose (CMC). Known most widely by its trade name, Seprafilm (Genzyme Corp), this bioresorbable product is composed of sodium HA and CMC, a combination that produces a transparent and absorbable membrane that lasts for 7 days after application.^10,11

In a study of 259 patients undergoing laparotomy for bowel resection or enterolysis, the incidence of repeat bowel obstruction was similar in the group treated with Seprafilm and the historical control group.¹¹ However, 9 of 12 bowel obstructions in the treated group resolved without surgery, compared with 5 of 12 in the control group. The enterolysis rate in the treated group was 1.5%, compared with 3.9% in the control group.

Because of its stickiness, Seprafilm is not ideal for laparoscopy. However, it can be rolled and passed through the trocar, with the film separated from its paper backing inside the abdominal cavity.

Oxidized regenerated cellulose. Known under the brand name Interceed (TC7), this absorbable adhesion barrier (Johnson & Johnson) is the most widely studied product available today. Several randomized trials have shown that it reduces postoperative formation of adhesions on the pelvic sidewalls and near the adnexa.^12-14

The efficacy of Interceed is reduced in the presence of blood. It is the easiest adhesion barrier to use at laparoscopy.

Newer agents in development include CMC and polyethylene oxide (PEO) composite gel (Oxiplex/AP, FrizoMed) and polylactide (PLa): copolymer of 70:30 Poly (L-lactide-co-D,L-lactide) film (SurgiWrap, Mast Biosurgery).

TABLE 2

The array of selected adhesion barriers and peritoneal instillates, and how they work

Peritoneal instillates

The newest peritoneal instillate is 4% icodextrin solution (Adept, Baxter BioSurgery). It is FDA-approved for the reduction of adhesion reformation after laparoscopic adhesiolysis. In a randomized study, the authors found that instillation of 4% icodextrin solution decreased adhesion formation and reformation after laparoscopic gynecologic surgery.¹⁵

Hyaluronic acid. Intergel (Lifecore, Johnson & Johnson Gynecare) is a cross-linked HA with ferric ion. It effectively reduces the number, severity, and extent of adhesions after abdominal operation.¹⁶ However, the product was withdrawn from the market after several reports of late-onset postoperative pain requiring surgery.

Sepracoat. This product (HAL-C Bioresorbable Membrane, Genzyme Corp) is a modification of Seprafilm. It coats serosal surfaces and is absorbed from the peritoneal cavity within 7 days. Its mechanism of action includes the reduction of tissue desiccation. Preliminary data show it to be effective in reducing postoperative adhesions.¹⁷ However, it did not receive FDA approval for clinical use, and was withdrawn from the market in 1997.

Hydrogel. A novel technique of substance delivery into the abdominal cavity is by combining 2 streams of liquid polymers, delivered via catheter to target tissue. When combined, the 2 streams produce a solid polymer within minutes. Sprayable hydrogel (SprayGel, Confluent Surgical) can be easily applied at laparoscopy. The solid polymer acts as an adhesion barrier and can potentially serve as a vehicle for localized delivery of drugs.

In a randomized study, Mettler et al¹⁸ evaluated 66 women who underwent myomectomy with or without SprayGel application. Second-look laparoscopy was performed in 40 women. Seven of 22 patients (31.8%) in the SprayGel group and 2 of 18 patients (11.1%) in the control group remained free of adhesions. However, the power of this study is small, and the authors did not break the women into subgroups based on whether they underwent surgery via laparoscopy or laparotomy. In the United States, the pivotal study of SprayGel was stopped prior to completion.

A similar product is a sprayable selfpolymerizing gel called Adhibit (Angiotech). An unpublished study from Europe showed it to be promising.

Fibrin sealant. Fibrin glue (Tissucol, Baxter) has been used as an adhesion-reducing substance, although clinical data on this application are scarce. This product is not approved by the FDA.

Which operations are the biggest culprits?