Microsurgical use of polydioxanone (PDS) suture: an experimental report

Stricture incidence related to suture material in hypospadias surgery

PURPOSE

To report the complication rates after hypospadias surgery, with stratification according to the type of suture used for the urethral anastomosis (rapid/intermediate absorbable v prolonged absorbable.)

MATERIAL AND METHODS

During a 7-year period (1986 to 1992), 117 boys aged 5 to 124 months (mean, 14) underwent surgical correction of hypospadias. The urethral anastomoses were performed with chromic sutures before 1987 (n = 15), with polydioxanone (PDS) between 1987 and 1990 (n = 46), and with polyglycolic acid (PgA) after 1990 (n = 56). The patients were separated into two groups: those whose operations were performed before 1987 and after 1990 (using chromic or PgA sutures), and those whose surgery occurred in the intervening 3 years (using PDS). A successful result was defined as good cosmesis without urethral stricture or urethrocutaneous fistula on long-term follow up (mean follow-up period, 15.9 months).

RESULTS

Of the cases that had PgA or chromic sutures, 76.1% were corrected in a single operation, as opposed to 50.9% when PDS was used (P = .002). In the chromic/PgA group, 6.8% had strictures, compared with 23.6% of the PDS group (P < .02). This contrast was most evident in cases with pedicled tube flaps; strictures occurred in 43.8% of the PDS group but in only 9.5% of the chromic/ PgA group (P < .02). There was no significant difference in the incidence of postoperative fistulas between the two groups. In some patients, the PDS sutures remained present in the urethra, without absorption, up to 7 months after the initial repair.

CONCLUSION

Sutures with rapid or intermediate absorption rates provide the best results for hypospadias surgery. The extreme delay in in vivo absorption of polydioxanone should preclude its use as an interrupted suture in small-caliber urethral anastomoses.

Comparison of nylon and polypropylene sutures in a microvenous thrombosis model

Thrombosis rates of femoral end-to-end microvenous anastomoses with nylon and polypropylene sutures (9-0 suture, 70 mu needle) were compared in a microvenous thrombosis model. The vessel injuries were produced during anastomosis by using a suture with a knot 1 cm from the needle. Anastomotic thrombosis rates were assessed by visual inspection and strip test at 24 hr postoperatively. Low thrombosis rates (0% and 20%, respectively) of anastomoses with both unknotted nylon and unknotted polypropylene sutures were obtained. Anastomoses with knotted nylon and polypropylene sutures resulted in 65% and 45% thrombosis rates, respectively. Statistical analyses showed that there were no significant differences between thrombosis rates, both in anastomosis performance with unknotted nylon and polypropylene sutures (P > 0.05) and with knotted nylon and polypropylene sutures (P > 0.05), while there were significant differences between the thrombosis rate using unknotted sutures and knotted sutures (P < 0.01). It was concluded that vascular injury, not suture material, is the main factor leading to thrombosis in this model.

Methods and materials for wound management

Rumor, myth, and unsubstantiated opinion have guided wound management since our forebearers achieved upright ambulation. The past decade has seen discovery of specific substances and pathways that initiate, control, and terminate healing. The roles of oxygen, nutrition, and growth factors are rapidly revealing themselves to wound healing researchers, and a scientific basis for wound management is emerging. Although the healing process still harbors much mystery, we know enough to improve our methods of wound management. We can now pick from a variety of tools for surgical incision. Scientific studies help in the choice of sutures, needles, and needle holders, as well as alternative closure methods and materials. Natural and synthetic tissue adhesives vie with staples and tapes for use in wound repair. Dressing materials may be active, passive, selectively interactive, or inert. Wound management can be changed to meet changing wound needs, with dressings as diverse as hydrocolloids, silicone gels, and amino acids. We have new ways of improving hypertrophic scarring and practical hopes for its prevention. This article offers a summary of currently available methods and materials for wound management, along with the scientific information that supports and guides their use.