- Email: [email protected]
Comparison of BioGlue reinforced and standard running sutured vesicourethral anastomoses
BASIC SCIENCE
COMPARISON OF BioGlue REINFORCED AND STANDARD RUNNING SUTURED VESICOURETHRAL ANASTOMOSES GREGORY HRUBY, FRANZO MARRUFFO, EVREN DURAK, SEAN COLLINS, ALAN HERRON, AND JAIME LANDMAN
ABSTRACT Objectives. To compare a BioGlue-reinforced laparoscopically sutured vesicourethral anastomosis (VUA) with a standard laparoscopically sutured VUA in a porcine model. Methods. Twelve pigs were divided into two groups. In group 1 (n ⫽ 6), a standard laparoscopically sutured VUA was performed. In group 2 (n ⫽ 6), a standard laparoscopic sutured VUA was performed, and the anastomosis was reinforced with BioGlue. Groups 1 and 2 were completed consecutively. The animals in both groups were killed at 1 week postoperatively. In all cases, cystography was performed immediately after completion of the anastomosis and at death. At necropsy, the gross findings of the VUA were documented, and each anastomosis was excised en bloc for an extensive histopathologic evaluation of the healing parameters, including inflammation and fibrosis at each tissue level, foreign body reactions, and necrosis. Results. Of the 12 VUAs, 11 were successfully performed laparoscopically. The median operative time for groups 1 and 2 was 70 and 100 minutes, respectively (P ⫽ 0.03). The median anastomotic time for groups 1 and 2 was 30 and 50 minutes, respectively (P ⫽ 0.02). No difference was seen in urinary extravasation on the cystographic evaluation in the immediate postoperative or 1-week evaluations. At necropsy, a gross complete circumferential histologic tissue approximation was noted in 1 (20%) of 5 pigs in group 1 and 2 (33%) of 6 pigs in group 2 (P ⫽ 0.66). No urinomas were noted in either group. Histopathologic evaluation revealed no significant difference between groups 1 and 2 regarding inflammation, fibrosis, foreign body reactions, or necrosis. Conclusions. The application of BioGlue to the anastomotic line extended the procedure time and did not improve the quality of the VUA. UROLOGY 68: 1355–1359, 2006. © 2006 Elsevier Inc.
A
challenging component of any open or laparoscopic radical prostatectomy is the vesicourethral anastomosis (VUA). Some of the major complications associated with radical prostatectomy are related to the VUA. Optimizing the quality of the VUA by creation of a watertight tension-free anastomosis will minimize these complications. To successfully perform a high-quality VUA, the surgeon must overcome significant challenges, including tissue exposure in the confined area of the pelvis, fragile tissue quality, and physician fatigue.1 J. Landman is a study investigator funded by CryoLife, Incorporated. From the Department of Urology and Institute of Comparative Medicine, Columbia University Medical Center, New York, New York Reprint requests: Jaime Landman, M.D., Department of Urology, Columbia University Medical Center, 161 Fort Washington Avenue, Room 1111, New York, NY 10032. E-mail: landmanj@ yahoo.com Submitted: March 31, 2006, accepted (with revisions): September 13, 2006 © 2006 ELSEVIER INC. ALL RIGHTS RESERVED
Even after the learning curve has been accomplished, the laparoscopic VUA can still pose a problem for the surgeon.2 Recently, a number of surgical pharmaceuticals have been introduced into clinical practice with the promise of helping surgeons with hemostasis and minimizing leakage. One such product is BioGlue (CryoLife, Kennesaw, Ga). BioGlue is a combination of glutaraldehyde and purified bovine albumin. The mixture of these components creates albumin-albumin cross-links and, when applied to tissue, will create albumin-tissue cross-links (Fig. 1). The result is an adhesive that can seal or link apposing tissues within a short period. The polymerized BioGlue releases amounts of glutaraldehyde that are capable of inducing cytotoxic effects both in vitro and in vivo.3 Even so, BioGlue was approved in the United States in 1999 as a surgical adhesive for use in cardiovascular operations as a surgical adjunct to suture lines.4 It has been shown to effectively increase hemostasis during thoracic 0090-4295/06/$32.00 doi:10.1016/j.urology.2006.09.032 1355
FIGURE 2. (A) BioGlue rigid applicator used to apply BioGlue laparoscopically. (B) Rigid applicator and applicator tip junction (arrow) that was the cause of four of six application failures because of annealed glue at this junction.
aortic surgery.5 As such, we evaluated the application of BioGlue to the VUA. MATERIAL AND METHODS
FIGURE 1. (A) BioGlue (BG) and tissue crosslink. Note, necrotic ring (white arrow) between healthy tissue and BioGlue. (B) Lesion of BioGlue (black arrow) removed from gross tissue specimen, leaving large defect (white arrow). Gross application thought to be caused by pseudo clog that was overcome by excessive force. (C) Microscopic picture depicting BioGlue (BG) in anastomotic line entering lumen and preventing healing of anastomosis. 1356
Our Institutional Animal Care and Use Committee approved the investigation. Power calculations were not performed to obtain a sample size. This investigation was a pilot evaluation examining all possible areas of comparison. Twelve domestic pigs were divided into two groups. The pigs in group 1 (n ⫽ 6) underwent a standard running VUA. The pigs in group 2 (n ⫽ 6) underwent a running VUA that was reinforced with BioGlue. All group 1 procedures were completed consecutively and then followed by the group 2 procedures. Three surgeons (G.H., F.M., and E.D.) with at least 1 year of laparoscopic experience performed the VUAs. All animals survived for 1 week with bladder decompression and a Foley catheter. On arrival, the animals were allowed to acclimate for 2 days before the procedures were performed. The pigs were initially anesthetized with ketamine 5 to 10 mg/kg and then intubated. The pigs were brought to the surgical suite and the anesthetic was maintained with 2% to 5% isofluorane. All pigs were placed in the supine position, and a Foley catheter was placed in a sterile manner. The animals were then prepared and draped, and transperitoneal access was gained using three 10-mm trocars: one at the umbilicus and two inferior to the umbilicus and lateral to the rectus abdominus muscles. The bladder was identified and mobilized for bladder neck dissection. The ureters were identified, and the urethra was incised caudal to the ureteral orifices. To prevent ureteral orifice obstruction resulting from Foley catheter deployment, we developed a technique to move the bladder neck anteriorly. In all cases, the bladder neck was incised anteriorly, and a “tennis racket” closure was performed posteriorly with interrupted 2-0 Vicryl suture on an SH needle (Ethicon, Cincinnati, Ohio) to reconstruct the bladder neck. In group 1, a standard Van Velthoven running anastomosis was performed using 2-0 Vicryl suture on an SH needle.6 Two 6-cm sutures were tied together, and the running anastomosis was initiated at the 6-o’clock position on the posterior bladder neck. When the posterior portion of the VUA was completed, the catheter was reintroduced into the bladder and the anterior portion of the anastomosis was completed. The VUA of group 2 was completed in the same manner as in group 1, with the addition of BioGlue to the anastomosis. The BioGlue was prepared according to the manufacturer’s directions. A prototype rigid adapter (CryoLife, Kennesaw, Ga) was used for BioGlue application (Fig. 2). The BioGlue was applied to the suture line, minimizing exposure of the urothelial surface to the BioGlue. To ensure circumferential application of the surgical adhesive, the VUA was first rotated 90° counterclockwise and then 90° clockwise for posterior application. The porcine UROLOGY 68 (6), 2006
vesicourethral junction is intraperitoneal and therefore very mobile, making this maneuver possible in an atraumatic manner. After application of BioGlue to the posterior aspect of the VUA, the VUA was relaxed for anterior application of the surgical adhesive. The operative and VUA times were recorded. After completion of each anastomosis, each animal underwent visual inspection of the anastomosis by way of a 250-mL cystogram (Conray, Mallinckrodt, St. Louis, Mo) performed using gravity infusion at a pressure of 40 cm H2O. Any visual abnormalities, such as a visible flow of fluid, were documented. Fluoroscopy was also used to grade extravasation of the anastomosis (0, none; 1, minimal; 2, moderate; and 3, severe extravasation). After the cystogram was performed, the bladder was allowed to drain to completion by gravity drainage and the fluid that returned from the bladder was collected, and measured, and the results were documented. All animals were kept alive for 1 week. Before death, cystography was performed as previously described. The fluid that returned from the cystogram was collected and measured. Next, the animals were killed, and the entire area of the anastomosis was harvested en bloc and placed in 5% formalin for fixation and later histopathologic examination. Gross observation of circumferential healing and BioGlue appearance was documented at harvest. Each VUA was divided into three sections and placed in tissue cassettes for permanent cross-sections of the anastomotic line. The slides were stained with hematoxylin-eosin in a standard manner. Three slides from each cassette were evaluated and graded by a pathologist (A.H.) unaware of the treatment group on a grading scale of 0 to 3 (0, none; 1, minimal; 2, moderate; and 3, severe changes). The evaluated parameters included the inflammatory reactions (mural, lamia propria, edema, and perianastomotic fat inflammation), fibrotic reactions (muscle, lamina propria, granulation, perianastomotic fat, and myofibroblasts), and other categories (foreign body, squamous metaplasia, mucinous metaplasia, hemosiderin deposits, perianastomotic hemorrhage, necrotic debris, and intact urothelium). The Wilcoxon rank sum test was used to evaluate the operative times, fluid returned on the immediate postoperative and 1-week postoperative cystograms, and the animal’s weight. Fisher’s exact test was used to evaluate the subjective histologic scores of the groups on the basis of the percentage of animals with a severe change recorded from baseline.
RESULTS Five (83%) of the six standard VUAs and all six of the BioGlue-reinforced VUAs were successfully completed. One pig in group 1 died of an access-related surgical complication. The median operative time for groups 1 and 2 was 70 and 100 minutes, respectively (P ⫽ 0.03). The median anastomotic time for groups 1 and 2 was 30 and 50 minutes, respectively (P ⫽ 0.02). The median extravasation score for the immediate postoperative cystogram for groups 1 and 2 was 0 (range 0) and 1 (range 1), respectively (P ⫽ 0.03). The median fluid returned from the immediate postoperative cystogram for groups 1 and 2 was 250 and 215 mL, respectively (P ⫽ 0.22). The median extravasation score for the 1-week postoperative cystogram for groups 1 and 2 was 0 (range 0) and 1 (range 0 to 3), respectively (P ⫽ 0.05). The mean fluid returned from the 1-week postoperative UROLOGY 68 (6), 2006
cystogram was 240 mL for both groups (P ⫽ 0.92). All 11 animals survived to the desired point with their catheters in place. Two (33%) of the six BioGlue applications were performed without complications. However, during four (67%) of the six procedures, the surgeon experienced applicator tip clogging because of premature mixing of the BioGlue components; the surgical adhesive had prematurely annealed within the applicator/applicator tip junction (Fig. 2). Of the four animals with premature clogging of the applicator device, two experienced a gross application of BioGlue to the anastomotic line. In these two animals, additional manual pressure to the applicator was used to deploy the BioGlue, resulting in the gross application of the BioGlue. At necropsy, gross observation of the VUAs of group 2 revealed 4 (67%) of 6 pigs with complete circumferential application of BioGlue. Of these 4 animals, 2 had gross amounts of BioGlue on the posterior side of the anastomosis (Fig. 1) The pigs with gross amounts of BioGlue were those in which a larger volume of BioGlue was inadvertently deployed on the VUA. Table I lists the percentage of histopathologic grades recorded with a severe change from baseline. Microscopic observation of the histologic features showed BioGlue leakage across the anastomosis and into the lumen of the urethra in 4 (67%) of the 6 cases (Fig. 1). COMMENT Optimizing the quality of the VUA allows the urologist to minimize complications associated with the VUAs. The incidence of a minor urine leak complication for a minimally invasive approach ranges from 2% to 28.5%.7–9 This minor complication is usually resolved with extended Foley decompression and conservative management. Many urine leaks even go unnoticed and resolve without intervention. However, urine leakage has been shown to lead to other complications such as back pain, uroperitoneum, and ileus.10 A more severe complication is a decreased early continence rate, which is associated with prolonged urine leakage.8 Urine leak can also result in more chronic problems such as bladder neck contracture. As such, we hoped to establish the use of BioGlue to reduce urine leakage on the anastomotic line and therefore improve the quality of the VUA. Surgeon experience is the largest factor associated with the quality of the laparoscopically sutured VUA.2 All surgeons had achieved the learning curve associated with intracorporeal suturing and knot tying by completing at least 50 laparoscopic procedures before the initiation of this study. 1357
TABLE I. Percentage of animals recorded with severe changes from baseline Histologic Finding Inflammatory reactions Mural inflammation Lamina propria inflammation Edema Perianastomotic fat inflammation Fibrotic reaction Muscle layer fibrosis Lamina propria fibrosis Granulation tissue Perianastomotic fat fibrosis Presence of myofibroblasts Other Focal foreign body reaction Squamous metaplasia Mucinous metaplasia Hemosiderin deposits Perianastomotic hemorrhage Necrotic debris
In this animal study, despite circumferential deployment of the BioGlue, the VUA performed with BioGlue did not result in an immediate watertight closure. All six BioGlue-reinforced VUAs showed minimal extravasation on fluoroscopy compared with no evidence of extravasation with the standard VUAs (P ⫽ 0.03). Similarly, at the 1-week point, the standard VUAs showed no evidence of extravasation, and the BioGlue-reinforced VUAs displayed minimal extravasation. The inferior quality of the VUA with the addition of the BioGlue may have resulted when the tissue cross-links with the BioGlue were disrupted, thereby creating a defect in the VUA. Several factors may have caused this disruption. The manipulation of the anastomosis to circumferentially apply the BioGlue to the VUA may have separated the tissue planes, allowing BioGlue to enter those sites. Also, the disruption of the cross-links between the tissue and the BioGlue may have been accelerated because of the large presence of urine at the surgical site. Alternatively, the BioGlue itself may act as a physical obstruction for the natural healing processes, including cell migration. The application of BioGlue was challenging and time consuming. The laparoscopic applicator often became clogged, rendering it unusable. This is concerning because the BioGlue cost per unit is about US$300.00. During 2 cases, an excessive amount of BioGlue was deployed over the VUA. We believe this problem resulted from a slight clogging in the applicator. When additional manual pressure was used to deploy the BioGlue, an excessive amount of the material was pushed into the operative field. In these cases, the large applications of BioGlue were identified in the gross observations at necropsy 1358
BioGlue (%)
Standard (%)
P Value
3/5 (60) 3/5 (60) 1/5 (20) 1/5 (20)
3/6 (50) 4/6 (67) 5/6 (83) 5/6 (83)
1 1 0.08 0.08
4/5 (80) 4/5 (80) 1/5 (20) 1/5 (20) 0/5 (0)
3/6 (50) 4/6 (67) 5/6 (83) 2/6 (33) 0/6 (0)
0.55 1 0.08 1
2/5 (40) 0/5 (0) 0/5 (0) 0/5 (0) 0/5 (0) 1/5 (20)
5/6 (83) 0/6 (0) 3/6 (50) 0/6 (0) 5/6 (83) 0/6 (0)
0.24 0.18 0.015 0.46
(Fig. 1). In these 2 animals, the BioGlue lesion seemed to prevent complete tissue approximation, thereby hindering tissue healing, as documented by immediate extravasation on the postoperative cystogram for these 2 animals. Two more animals in the BioGlue group experienced extravasation on the immediate postoperative cystogram. Additional evaluation of the 4 animals that experienced extravasation on the postoperative cystograms revealed microscopic evidence of BioGlue leakage throughout all the tissue layers of anastomosis and into the lumen of the urethra (Fig. 1) The BioGlue also prevented complete tissue healing of the anastomosis. Urine leakage in the anastomosis that included BioGlue was common, occurring in 4 (67%) of 6 animals despite our concerted efforts during the procedures to keep the BioGlue only on the external surface of the anastomosis. CONCLUSIONS The application of BioGlue to the VUA was time consuming and did not result in improvement in the watertight anastomoses. Moreover, the reinforced anastomoses did not result in a superior healing response compared with the standard VUA. BioGlue should not be considered as an adjunct to the standard sutured VUA. REFERENCES 1. Nadu A, Olsson LE, and Abbou CC: Simple model for the training in the laparoscopic vesicourethral running anastomosis. J Endourol 17: 481– 484, 2003. 2. Ferguson GG, Ames CD, Weld KJ, et al: Prospective evaluation of learning curve for laparoscopic radical prostatectomy: identification of factors improving operative times. Urology 66: 840 – 844, 2005. UROLOGY 68 (6), 2006
3. Furst W, and Banerjee A: Release of gluteraldhyde from an albumin-glutaraldehyde tissue adhesive causes significant in vitro and in vivo toxicity. Ann Thorac Surg 79: 1552–1559, 2005. 4. Coselli JS, LeMaire SA, and Koksoy C: Thoracic aortic anastomoses. Op Tech Thorac Cardiovasc Surg 5: 259–276, 2000. 5. Coselli JS, Bavaria JE, Fehrenbacher J, et al: Prospective randomized study of a protein based tissue adhesive used as a hemostatic and structural adjunct in cardiac and vascular anastomotic repair procedures. J Am Coll Surg 197: 243–253, 2003. 6. Van Velthoven RF, Ahlering TE, Peltier A, et al: Technique for laparoscopic running urethrovesical anastomosis: the single knot method. Urology 61: 699 –702, 2003.
UROLOGY 68 (6), 2006
7. Hu JC, Nelson RA, Wilson TG, et al: Perioperative complications of laparoscopic and robotic assisted laparoscopic radical prostatectomy. J Urol 175: 541–546, 2006. 8. Gnanapragasam VJ, Baker P, Naisby GP, et al: Identification and validation of risk factors for vesicourethral leaks following radical retropubic prostatectomy. Int J Urol 12: 948 –952, 2005. 9. Remzi M, Klingler HC, Tinzl MV, et al: Morbidity of laparoscopic extraperitoneal versus transperitoneal radical prostatectomy versus open retropubic radical prostatectomy. Eur Urol 48: 83– 89, 2005. 10. Touijer K, and Guillonneau B: Laparoscopic radical prostatectomy: a critical analysis of surgical quality. Eur Urol 49: 625– 632, 2006.
1359
COMPARISON OF BioGlue REINFORCED AND STANDARD RUNNING SUTURED VESICOURETHRAL ANASTOMOSES GREGORY HRUBY, FRANZO MARRUFFO, EVREN DURAK, SEAN COLLINS, ALAN HERRON, AND JAIME LANDMAN
ABSTRACT Objectives. To compare a BioGlue-reinforced laparoscopically sutured vesicourethral anastomosis (VUA) with a standard laparoscopically sutured VUA in a porcine model. Methods. Twelve pigs were divided into two groups. In group 1 (n ⫽ 6), a standard laparoscopically sutured VUA was performed. In group 2 (n ⫽ 6), a standard laparoscopic sutured VUA was performed, and the anastomosis was reinforced with BioGlue. Groups 1 and 2 were completed consecutively. The animals in both groups were killed at 1 week postoperatively. In all cases, cystography was performed immediately after completion of the anastomosis and at death. At necropsy, the gross findings of the VUA were documented, and each anastomosis was excised en bloc for an extensive histopathologic evaluation of the healing parameters, including inflammation and fibrosis at each tissue level, foreign body reactions, and necrosis. Results. Of the 12 VUAs, 11 were successfully performed laparoscopically. The median operative time for groups 1 and 2 was 70 and 100 minutes, respectively (P ⫽ 0.03). The median anastomotic time for groups 1 and 2 was 30 and 50 minutes, respectively (P ⫽ 0.02). No difference was seen in urinary extravasation on the cystographic evaluation in the immediate postoperative or 1-week evaluations. At necropsy, a gross complete circumferential histologic tissue approximation was noted in 1 (20%) of 5 pigs in group 1 and 2 (33%) of 6 pigs in group 2 (P ⫽ 0.66). No urinomas were noted in either group. Histopathologic evaluation revealed no significant difference between groups 1 and 2 regarding inflammation, fibrosis, foreign body reactions, or necrosis. Conclusions. The application of BioGlue to the anastomotic line extended the procedure time and did not improve the quality of the VUA. UROLOGY 68: 1355–1359, 2006. © 2006 Elsevier Inc.
A
challenging component of any open or laparoscopic radical prostatectomy is the vesicourethral anastomosis (VUA). Some of the major complications associated with radical prostatectomy are related to the VUA. Optimizing the quality of the VUA by creation of a watertight tension-free anastomosis will minimize these complications. To successfully perform a high-quality VUA, the surgeon must overcome significant challenges, including tissue exposure in the confined area of the pelvis, fragile tissue quality, and physician fatigue.1 J. Landman is a study investigator funded by CryoLife, Incorporated. From the Department of Urology and Institute of Comparative Medicine, Columbia University Medical Center, New York, New York Reprint requests: Jaime Landman, M.D., Department of Urology, Columbia University Medical Center, 161 Fort Washington Avenue, Room 1111, New York, NY 10032. E-mail: landmanj@ yahoo.com Submitted: March 31, 2006, accepted (with revisions): September 13, 2006 © 2006 ELSEVIER INC. ALL RIGHTS RESERVED
Even after the learning curve has been accomplished, the laparoscopic VUA can still pose a problem for the surgeon.2 Recently, a number of surgical pharmaceuticals have been introduced into clinical practice with the promise of helping surgeons with hemostasis and minimizing leakage. One such product is BioGlue (CryoLife, Kennesaw, Ga). BioGlue is a combination of glutaraldehyde and purified bovine albumin. The mixture of these components creates albumin-albumin cross-links and, when applied to tissue, will create albumin-tissue cross-links (Fig. 1). The result is an adhesive that can seal or link apposing tissues within a short period. The polymerized BioGlue releases amounts of glutaraldehyde that are capable of inducing cytotoxic effects both in vitro and in vivo.3 Even so, BioGlue was approved in the United States in 1999 as a surgical adhesive for use in cardiovascular operations as a surgical adjunct to suture lines.4 It has been shown to effectively increase hemostasis during thoracic 0090-4295/06/$32.00 doi:10.1016/j.urology.2006.09.032 1355
FIGURE 2. (A) BioGlue rigid applicator used to apply BioGlue laparoscopically. (B) Rigid applicator and applicator tip junction (arrow) that was the cause of four of six application failures because of annealed glue at this junction.
aortic surgery.5 As such, we evaluated the application of BioGlue to the VUA. MATERIAL AND METHODS
FIGURE 1. (A) BioGlue (BG) and tissue crosslink. Note, necrotic ring (white arrow) between healthy tissue and BioGlue. (B) Lesion of BioGlue (black arrow) removed from gross tissue specimen, leaving large defect (white arrow). Gross application thought to be caused by pseudo clog that was overcome by excessive force. (C) Microscopic picture depicting BioGlue (BG) in anastomotic line entering lumen and preventing healing of anastomosis. 1356
Our Institutional Animal Care and Use Committee approved the investigation. Power calculations were not performed to obtain a sample size. This investigation was a pilot evaluation examining all possible areas of comparison. Twelve domestic pigs were divided into two groups. The pigs in group 1 (n ⫽ 6) underwent a standard running VUA. The pigs in group 2 (n ⫽ 6) underwent a running VUA that was reinforced with BioGlue. All group 1 procedures were completed consecutively and then followed by the group 2 procedures. Three surgeons (G.H., F.M., and E.D.) with at least 1 year of laparoscopic experience performed the VUAs. All animals survived for 1 week with bladder decompression and a Foley catheter. On arrival, the animals were allowed to acclimate for 2 days before the procedures were performed. The pigs were initially anesthetized with ketamine 5 to 10 mg/kg and then intubated. The pigs were brought to the surgical suite and the anesthetic was maintained with 2% to 5% isofluorane. All pigs were placed in the supine position, and a Foley catheter was placed in a sterile manner. The animals were then prepared and draped, and transperitoneal access was gained using three 10-mm trocars: one at the umbilicus and two inferior to the umbilicus and lateral to the rectus abdominus muscles. The bladder was identified and mobilized for bladder neck dissection. The ureters were identified, and the urethra was incised caudal to the ureteral orifices. To prevent ureteral orifice obstruction resulting from Foley catheter deployment, we developed a technique to move the bladder neck anteriorly. In all cases, the bladder neck was incised anteriorly, and a “tennis racket” closure was performed posteriorly with interrupted 2-0 Vicryl suture on an SH needle (Ethicon, Cincinnati, Ohio) to reconstruct the bladder neck. In group 1, a standard Van Velthoven running anastomosis was performed using 2-0 Vicryl suture on an SH needle.6 Two 6-cm sutures were tied together, and the running anastomosis was initiated at the 6-o’clock position on the posterior bladder neck. When the posterior portion of the VUA was completed, the catheter was reintroduced into the bladder and the anterior portion of the anastomosis was completed. The VUA of group 2 was completed in the same manner as in group 1, with the addition of BioGlue to the anastomosis. The BioGlue was prepared according to the manufacturer’s directions. A prototype rigid adapter (CryoLife, Kennesaw, Ga) was used for BioGlue application (Fig. 2). The BioGlue was applied to the suture line, minimizing exposure of the urothelial surface to the BioGlue. To ensure circumferential application of the surgical adhesive, the VUA was first rotated 90° counterclockwise and then 90° clockwise for posterior application. The porcine UROLOGY 68 (6), 2006
vesicourethral junction is intraperitoneal and therefore very mobile, making this maneuver possible in an atraumatic manner. After application of BioGlue to the posterior aspect of the VUA, the VUA was relaxed for anterior application of the surgical adhesive. The operative and VUA times were recorded. After completion of each anastomosis, each animal underwent visual inspection of the anastomosis by way of a 250-mL cystogram (Conray, Mallinckrodt, St. Louis, Mo) performed using gravity infusion at a pressure of 40 cm H2O. Any visual abnormalities, such as a visible flow of fluid, were documented. Fluoroscopy was also used to grade extravasation of the anastomosis (0, none; 1, minimal; 2, moderate; and 3, severe extravasation). After the cystogram was performed, the bladder was allowed to drain to completion by gravity drainage and the fluid that returned from the bladder was collected, and measured, and the results were documented. All animals were kept alive for 1 week. Before death, cystography was performed as previously described. The fluid that returned from the cystogram was collected and measured. Next, the animals were killed, and the entire area of the anastomosis was harvested en bloc and placed in 5% formalin for fixation and later histopathologic examination. Gross observation of circumferential healing and BioGlue appearance was documented at harvest. Each VUA was divided into three sections and placed in tissue cassettes for permanent cross-sections of the anastomotic line. The slides were stained with hematoxylin-eosin in a standard manner. Three slides from each cassette were evaluated and graded by a pathologist (A.H.) unaware of the treatment group on a grading scale of 0 to 3 (0, none; 1, minimal; 2, moderate; and 3, severe changes). The evaluated parameters included the inflammatory reactions (mural, lamia propria, edema, and perianastomotic fat inflammation), fibrotic reactions (muscle, lamina propria, granulation, perianastomotic fat, and myofibroblasts), and other categories (foreign body, squamous metaplasia, mucinous metaplasia, hemosiderin deposits, perianastomotic hemorrhage, necrotic debris, and intact urothelium). The Wilcoxon rank sum test was used to evaluate the operative times, fluid returned on the immediate postoperative and 1-week postoperative cystograms, and the animal’s weight. Fisher’s exact test was used to evaluate the subjective histologic scores of the groups on the basis of the percentage of animals with a severe change recorded from baseline.
RESULTS Five (83%) of the six standard VUAs and all six of the BioGlue-reinforced VUAs were successfully completed. One pig in group 1 died of an access-related surgical complication. The median operative time for groups 1 and 2 was 70 and 100 minutes, respectively (P ⫽ 0.03). The median anastomotic time for groups 1 and 2 was 30 and 50 minutes, respectively (P ⫽ 0.02). The median extravasation score for the immediate postoperative cystogram for groups 1 and 2 was 0 (range 0) and 1 (range 1), respectively (P ⫽ 0.03). The median fluid returned from the immediate postoperative cystogram for groups 1 and 2 was 250 and 215 mL, respectively (P ⫽ 0.22). The median extravasation score for the 1-week postoperative cystogram for groups 1 and 2 was 0 (range 0) and 1 (range 0 to 3), respectively (P ⫽ 0.05). The mean fluid returned from the 1-week postoperative UROLOGY 68 (6), 2006
cystogram was 240 mL for both groups (P ⫽ 0.92). All 11 animals survived to the desired point with their catheters in place. Two (33%) of the six BioGlue applications were performed without complications. However, during four (67%) of the six procedures, the surgeon experienced applicator tip clogging because of premature mixing of the BioGlue components; the surgical adhesive had prematurely annealed within the applicator/applicator tip junction (Fig. 2). Of the four animals with premature clogging of the applicator device, two experienced a gross application of BioGlue to the anastomotic line. In these two animals, additional manual pressure to the applicator was used to deploy the BioGlue, resulting in the gross application of the BioGlue. At necropsy, gross observation of the VUAs of group 2 revealed 4 (67%) of 6 pigs with complete circumferential application of BioGlue. Of these 4 animals, 2 had gross amounts of BioGlue on the posterior side of the anastomosis (Fig. 1) The pigs with gross amounts of BioGlue were those in which a larger volume of BioGlue was inadvertently deployed on the VUA. Table I lists the percentage of histopathologic grades recorded with a severe change from baseline. Microscopic observation of the histologic features showed BioGlue leakage across the anastomosis and into the lumen of the urethra in 4 (67%) of the 6 cases (Fig. 1). COMMENT Optimizing the quality of the VUA allows the urologist to minimize complications associated with the VUAs. The incidence of a minor urine leak complication for a minimally invasive approach ranges from 2% to 28.5%.7–9 This minor complication is usually resolved with extended Foley decompression and conservative management. Many urine leaks even go unnoticed and resolve without intervention. However, urine leakage has been shown to lead to other complications such as back pain, uroperitoneum, and ileus.10 A more severe complication is a decreased early continence rate, which is associated with prolonged urine leakage.8 Urine leak can also result in more chronic problems such as bladder neck contracture. As such, we hoped to establish the use of BioGlue to reduce urine leakage on the anastomotic line and therefore improve the quality of the VUA. Surgeon experience is the largest factor associated with the quality of the laparoscopically sutured VUA.2 All surgeons had achieved the learning curve associated with intracorporeal suturing and knot tying by completing at least 50 laparoscopic procedures before the initiation of this study. 1357
TABLE I. Percentage of animals recorded with severe changes from baseline Histologic Finding Inflammatory reactions Mural inflammation Lamina propria inflammation Edema Perianastomotic fat inflammation Fibrotic reaction Muscle layer fibrosis Lamina propria fibrosis Granulation tissue Perianastomotic fat fibrosis Presence of myofibroblasts Other Focal foreign body reaction Squamous metaplasia Mucinous metaplasia Hemosiderin deposits Perianastomotic hemorrhage Necrotic debris
In this animal study, despite circumferential deployment of the BioGlue, the VUA performed with BioGlue did not result in an immediate watertight closure. All six BioGlue-reinforced VUAs showed minimal extravasation on fluoroscopy compared with no evidence of extravasation with the standard VUAs (P ⫽ 0.03). Similarly, at the 1-week point, the standard VUAs showed no evidence of extravasation, and the BioGlue-reinforced VUAs displayed minimal extravasation. The inferior quality of the VUA with the addition of the BioGlue may have resulted when the tissue cross-links with the BioGlue were disrupted, thereby creating a defect in the VUA. Several factors may have caused this disruption. The manipulation of the anastomosis to circumferentially apply the BioGlue to the VUA may have separated the tissue planes, allowing BioGlue to enter those sites. Also, the disruption of the cross-links between the tissue and the BioGlue may have been accelerated because of the large presence of urine at the surgical site. Alternatively, the BioGlue itself may act as a physical obstruction for the natural healing processes, including cell migration. The application of BioGlue was challenging and time consuming. The laparoscopic applicator often became clogged, rendering it unusable. This is concerning because the BioGlue cost per unit is about US$300.00. During 2 cases, an excessive amount of BioGlue was deployed over the VUA. We believe this problem resulted from a slight clogging in the applicator. When additional manual pressure was used to deploy the BioGlue, an excessive amount of the material was pushed into the operative field. In these cases, the large applications of BioGlue were identified in the gross observations at necropsy 1358
BioGlue (%)
Standard (%)
P Value
3/5 (60) 3/5 (60) 1/5 (20) 1/5 (20)
3/6 (50) 4/6 (67) 5/6 (83) 5/6 (83)
1 1 0.08 0.08
4/5 (80) 4/5 (80) 1/5 (20) 1/5 (20) 0/5 (0)
3/6 (50) 4/6 (67) 5/6 (83) 2/6 (33) 0/6 (0)
0.55 1 0.08 1
2/5 (40) 0/5 (0) 0/5 (0) 0/5 (0) 0/5 (0) 1/5 (20)
5/6 (83) 0/6 (0) 3/6 (50) 0/6 (0) 5/6 (83) 0/6 (0)
0.24 0.18 0.015 0.46
(Fig. 1). In these 2 animals, the BioGlue lesion seemed to prevent complete tissue approximation, thereby hindering tissue healing, as documented by immediate extravasation on the postoperative cystogram for these 2 animals. Two more animals in the BioGlue group experienced extravasation on the immediate postoperative cystogram. Additional evaluation of the 4 animals that experienced extravasation on the postoperative cystograms revealed microscopic evidence of BioGlue leakage throughout all the tissue layers of anastomosis and into the lumen of the urethra (Fig. 1) The BioGlue also prevented complete tissue healing of the anastomosis. Urine leakage in the anastomosis that included BioGlue was common, occurring in 4 (67%) of 6 animals despite our concerted efforts during the procedures to keep the BioGlue only on the external surface of the anastomosis. CONCLUSIONS The application of BioGlue to the VUA was time consuming and did not result in improvement in the watertight anastomoses. Moreover, the reinforced anastomoses did not result in a superior healing response compared with the standard VUA. BioGlue should not be considered as an adjunct to the standard sutured VUA. REFERENCES 1. Nadu A, Olsson LE, and Abbou CC: Simple model for the training in the laparoscopic vesicourethral running anastomosis. J Endourol 17: 481– 484, 2003. 2. Ferguson GG, Ames CD, Weld KJ, et al: Prospective evaluation of learning curve for laparoscopic radical prostatectomy: identification of factors improving operative times. Urology 66: 840 – 844, 2005. UROLOGY 68 (6), 2006
3. Furst W, and Banerjee A: Release of gluteraldhyde from an albumin-glutaraldehyde tissue adhesive causes significant in vitro and in vivo toxicity. Ann Thorac Surg 79: 1552–1559, 2005. 4. Coselli JS, LeMaire SA, and Koksoy C: Thoracic aortic anastomoses. Op Tech Thorac Cardiovasc Surg 5: 259–276, 2000. 5. Coselli JS, Bavaria JE, Fehrenbacher J, et al: Prospective randomized study of a protein based tissue adhesive used as a hemostatic and structural adjunct in cardiac and vascular anastomotic repair procedures. J Am Coll Surg 197: 243–253, 2003. 6. Van Velthoven RF, Ahlering TE, Peltier A, et al: Technique for laparoscopic running urethrovesical anastomosis: the single knot method. Urology 61: 699 –702, 2003.
UROLOGY 68 (6), 2006
7. Hu JC, Nelson RA, Wilson TG, et al: Perioperative complications of laparoscopic and robotic assisted laparoscopic radical prostatectomy. J Urol 175: 541–546, 2006. 8. Gnanapragasam VJ, Baker P, Naisby GP, et al: Identification and validation of risk factors for vesicourethral leaks following radical retropubic prostatectomy. Int J Urol 12: 948 –952, 2005. 9. Remzi M, Klingler HC, Tinzl MV, et al: Morbidity of laparoscopic extraperitoneal versus transperitoneal radical prostatectomy versus open retropubic radical prostatectomy. Eur Urol 48: 83– 89, 2005. 10. Touijer K, and Guillonneau B: Laparoscopic radical prostatectomy: a critical analysis of surgical quality. Eur Urol 49: 625– 632, 2006.
1359