Beyond The Abstract Comparison Of Different Techniques For Hemostasis In A Rabbit Model Of Hypospadias Repair

Main Category: Urology / Nephrology
Also Included In: Clinical Trials / Drug Trials
Article Date: 10 Dec 2007 - 0:00 PDT


UroToday.com - An essential part of hypospadias repair procedure is to maintain a bloodless operation field. Currently, there are two main hemostasis techniques for this purpose, including the injection of vasoconstrictive agents and application of penile tourniquet. However, both methods may induce ischemia/reperfusion damage in urethral tissues. In present study, we studied both early and late cellular injury in the urethral wall tissues following application of different hemostasis methods in a rabbit model of hypospadias repair.

Five groups of rabbits were used: In group 1, animals underwent hypospadias surgery without application of any hemostasis technique. In group 2, we applied 30 min of continuous penile tourniquet, and in group 3, three 10-min intermittent torniquetting periods with 3-min intervals of reperfusion. In group 4, epinephrine (1:100,000 diluted with normal-saline) was injected beneath to the urothelium beside the incision line to maintain the hemostasis for 30 min (1). Group 5 rabbits received normal-saline injection under the urothelium.

Urethral samples for electron microscopic evaluation were obtained 1 hour after procedure and showed higher grades of ultrastructural damage in groups 2, 3, and 4 compared to groups 1 and 5. The changes were most prominent in epinephrine injection group. The myocytes apoptosis index, evaluated 48 hours after procedure, was higher in all three hemostasis groups compared to normal controls and normal-saline-injected controls. The number of apoptotic myocytes in epinephrine hemostasis group was also higher than both tourniquet groups. The percentage of collagen fibers in urethral wall was increased 8 weeks after epinephrine hemostasis in comparison with controls. We found no significant difference between continuous and intermittent penile tourniquet groups.

Our results reveal that hemostasis techniques applied for maintenance of a bloodless operation field throughout hypospadias repair induce ultrastructural and cellular damage in urethral wall. These changes were more prominent following epinephrine hemostasis. Additionally, we found no difference between application of continuous and intermittent penile tourniquet. However, one can not necessarily translate the presence of cellular damage to incidence of surgical complication, as the long-term results of hypospadias repair seem to depend on the severity of the initial abnormality rather than operative technique (2).

1. References: Snodgrass W. Tubularized, incised plate urethroplasty for distal hypospadias. J Urol 1994;151:464-465.

2. Nuininga JE, DE Gier RP, Verschuren R, Feitz WF. Long-term outcome of different types of 1-stage hypospadias repair. J Urol 2005 174(4 Pt 2):1544-1548.

Written by Abdol-Mohammad Kajbafzadeh, MD and Seyedmehdi Payabvash MD, as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.

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