Anatomy and Preservation of Accessory Pudendal Arteries in Laparoscopic Radical Prostatectomy

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1 european urology 51 (2007) available at journal homepage: Surgery in Motion Anatomy and Preservation of Accessory Pudendal Arteries in Laparoscopic Radical Prostatectomy Fernando P. Secin, Karim Touijer, John Mulhall, Bertrand Guillonneau * Department of Urology, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10021, USA Article info Article history: Accepted August 17, 2006 Published online ahead of print on September 1, 2006 Keywords: Accessory pudendal arteries Preservation Calibre Location Laparoscopic radical prostatectomy Positive surgical margin Abstract Objective: The incidence of laparoscopically diagnosed accessory pudendal arteries (APAs) varies depending on how proactive the surgeon is to find them. Their preservation depends on their calibre and location. Our objective was to provide a detailed description of how to identify, dissect, and preserve APAs during laparoscopic radical prostatectomy (LRP). Methods: Between January 2003 and January 2005, we treated 377 men with LRP; 325 met inclusion criteria for this study. We defined an APA as any artery located within the periprostatic region running parallel to the dorsal vascular complex and extending caudally towards the anterior perineum, other than cavernous arteries, corona mortis, and satellite arteries to the superficial and deep vascular complex. Two distinct varieties of APAs were identified: (1) lateral APAs course along the lateral aspect of the prostate and branch off any of the terminal branches of the hypogastric artery; and (2) apical APAs emerge through the levator ani fibres near the apical region of the prostate and most likely branch off the pudendal artery or corresponds to an aberrant course of the pudendal artery itself. We present a video depicting the laparoscopic anatomy of APAs and the technique to preserve them. Results: Ninety-six of 325 men (30%) were found to have 125 separate APAs. Using the depicted surgical technique, we were able to preserve 83% of all APAs. Forty-nine of 55 lateral APAs (89%) and 55 of 70 apical APAs (79%) were preserved. Thirty-five of 38 large-calibre APAs (92%) and 70 of 87 smallcalibre APAs (80%) were spared. The side-specific incidence of PSMs were 3% and 6% when APAs were preserved and not preserved, respectively ( p = 0.5). Conclusions: APAs are frequently identified during laparoscopic prostatectomy. Their preservation is feasible in LRP without increasing the risk of causing a PSM. It is reasonable to integrate APA preservation as part of the modern radical prostatectomy, although their role in functional outcomes still needs to be prospectively established. # 2006 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Tel ; Fax: address: guillonb@mskcc.org (B. Guillonneau) /$ see back matter # 2006 European Association of Urology. Published by Elsevier B.V. All rights reserved. doi: /j.eururo

2 1230 european urology 51 (2007) Introduction We previously identified either apical or lateral accessory pudendal arteries (APAs) in approximately 30% of patients undergoing laparoscopic radical prostatectomy (LRP), and these arteries were preserved 83% of the time [1,2]. More recently, data from the University of Texas M.D. Anderson Cancer Center reported an incidence of 25.7%, with a 78.3% preservation rate after collecting prospective data from 70 LRP [3]. In the open prostatectomy literature, the Johns Hopkins Hospital reported a 4% identification and a 78% preservation rate for large lateral APAs [4,5]. Although it is impossible to make fair comparisons between open and laparoscopic techniques in this respect, data suggest a 5- to 7-fold increase in APA identification with the laparoscopic technique, providing evidence of one of the potential benefits of the videoendoscopic magnification in association with a dryer surgical field. Most likely, this difference in the identification of APAs may occur at the expense of a higher number of arteries of smaller calibre being identified with the magnified lens. Notwithstanding, the impact of APAs on functional outcomes remains to be investigated. Our objective was to provide a detailed description of how to identify, dissect, and preserve APAs during LRP. Fig. 2 Left apical APA emerging through the fibres of the levator ani behind the puboprostatic (pubovesical) ligaments. 2. Materials and methods Between January 1, 2003 and January 30, 2005, we performed LRP on 377 men with clinically localized prostate cancer and no prior external beam radiation therapy to the prostate. Fifty-two individuals were excluded because of incomplete data. The remaining 325 patients comprised the study population. The approach in all cases was antegrade transperitoneal Fig. 3 Right-sided corona mortis, artery (dotted arrow) and vein (solid arrow). Note that the vein is always distal to the artery. Fig. 1 Right lateral APA after removing the prostate. LRP, as previously described [6]. Preoperative clinical and pathologic variables were prospectively recorded. Data on APA variety, size, distribution, and preservation status was recorded intraoperatively. Two distinct varieties of APAs were identified, lateral and apical. Lateral APAs course along the anterolateral aspect of the prostate, and they can be found running either in intimate contact with the anterolateral prostatic surface or closer to the endopelvic fascia, a few millimetres away from the gland (Fig. 1). Apical APAs are localized inferior and lateral to the pubovesical ligaments, close to the anterolateral aspect of the prostatic apex (Fig. 2). The cavernous arteries, corona mortis, and satellite arteries of the superficial and deep vascular complex are excluded from this definition (Fig. 3).

3 european urology 51 (2007) Fig. 4 Intrapelvic APAs classification by location. 3. Surgical technique 3.1. APA identification The identification of APAs within the pelvic cavity during LRP is related to both the index of suspicion and the proactive attitude on behalf of the surgeon. The degree of apical dissection also contributes to their increasing identification rate, particularly for apical APAs. Knowledge of their anatomy is crucial to suspect and recognize them before causing any artery damage Lateral APAs Localization of lateral APAs can be grouped into two main locations (Fig. 4): over the prostatic surface (prostatic APAs) and over the pelvic side wall. Prostatic APAs can be located either above or below the The former are the easiest to identify because no manoeuvres are needed to visualize them other than careful detachment of the bladder from the retropubic space. They are immediately seen after the bladder has been pulled back and the fat over the gland swept away (Fig. 5). The latter are recognized as a beating bump over the surface of the prostate but underneath the endopelvic fascia right before or during dissection of the anterior bladder neck (Fig. 6). APAs located over the pelvic side wall are identified either in the groove between the prostate and the pelvic side wall a few millimetres away from the gland (pelvic side wall APAs) or coursing right below the pubic bone (pubic APAs). Those found in the groove can run either above (Fig. 7) or below (Fig. 8) the endopelvic fascia and are consequently identified before or after incising it, respectively. While the ones running above the endopelvic fascia usually branch off the inferior vesical artery or the hypogastric arteries, the ones running below usually branch off the obturator artery. The APAs running below the pubic arch usually branch off the obturator artery, as well (Fig. 9). Unlike apical APAs and lateral APAs running below the pubic bone, lateral APAs coursing on the prostate surface or on the mentioned groove tend to be larger and, on occasions, bilateral. During the pelvic lymph node dissection, these last APAs can also be identified at their origin, as they branch off one of the terminal arteries of the hypogastric artery or the hypogastric artery itself (Fig. 10) Apical APAs Apical APAs are identifiable inferior and lateral to the puboprostatic (pubovesical) ligaments after incising either the distal end of the endopelvic fascia or the pubovesical ligaments. They characteristically emerge through the levator ani muscle fibres and tangentially approach the prostatic apex. Fig. 5 Left lateral prostatic APA running over the

4 1232 european urology 51 (2007) Fig. 6 Right lateral prostatic APA running below the Fig. 8 Left pelvic side wall APA located below the Instead of coursing along the lateral aspect of the prostate like lateral APAs, apical APAs extend directly to the prostatic apex before adopting a course parallel to the dorsal vascular complex (DVC) towards the perineum. Apical APAs were of smaller calibre 89% of the time and were identified on the left side in two-thirds of the cases [2]. Apical APAs presumably branch off either the obturator artery or the extrapelvic portion of the pudendal artery. It can be speculated that large apical APAs may represent aberrant pudendal arteries, while smaller ones might represent either accessory APAs or an intrapelvic branch of the pudendal artery. Depending on APA size, the endorectal coil magnetic resonance imaging or, more rarely, a pelvis computed tomograph imaging might be of help to identify APAs preoperatively, although its utility is currently under study (Fig. 11). Fig. 7 Left pelvic side wall APA located above the 3.2. APA preservation APA preservation is not as difficult as its identification. Following the logics of surgery, larger calibre APAs are easier to dissect and preserve than the smaller ones. Lateral APAs running over the endopelvic fascia are easily released from the surrounding fat, and most of the time they can be pushed laterally with blunt manoeuvres. APAs do not give off collateral branches until they reach the apex of the gland (Fig. 12). Lateral APAs running on the prostate surface but below the endopelvic fascia require active dissection with nano-bipolar forceps (1 mm) and scissors (Fig. 6). A neat plane of dissection can be developed between the anterior aspect of the APA and the onlaying endopelvic fascia with the tip of the scissors, which is subsequently divided using the same scissors, resembling what is normally done in open surgery. Blunt retraction of the APA with the aid of vessel loops may facilitate its dissection and minimize endothelial injury. Traction on the vessel loops can be applied with specific devices, like the Carter-Thomason needle passer, to avoid the placement of an additional port (see video). APAs should not be extensively mobilized, only as much as it is needed to keep them out of the way and safely complete the procedure. It may be helpful to leave some fat around the vessel (particularly lateral APAs) as it can be used as a handle and minimize arterial manipulation. As the APA approaches the DVC, it becomes surrounded by veins of the DVC, thus increasing the risk of venous damage and bleeding during its dissection. However, contrary to what happens in open prostatectomy, the tamponade effect of the

5 european urology 51 (2007) Fig. 9 Right lateral pubic APA branching off the right obturator artery. pneumoperitoneum minimizes venous bleeding and improves visualization, which ultimately facilitates dissection of the APA. Similar to lateral APAs, one or more collateral branches to the prostatic apex or the urethra are frequently identified, and they can be controlled with nano-bipolar forceps and sectioned with cold scissors. The dissection should be extended caudally beyond the site where the DVC is to be divided and sutured. In the presence of an APA, it may be safer to section the DVC first and then suture ligate it to reduce the likelihood of entrapping the APA with that stitch. We recommend increasing the pneumoperitoneum to a maximum of 20 mmhg to decrease blood loss from the incised DVC while Fig. 10 Lateral APA identified at its origin during performance of the extended lymph node dissection. Note that the hypogastric artery is giving its terminal branches ad modum tridentis: the obturator to the left, the umbilical artery to the right, and the lateral APA in between them (left side). Fig. 11 Left lateral APA observed (arrow) on preoperative computed tomograph imaging of the pelvis. P, prostate. the stitch suturing the lumens of the veins is secured. Dissection of APAs running on the pelvic side wall below the endopelvic fascia is similar to the one described; however, we recommend incision of the endopelvic fascia with cold scissors to avoid inadvertent thermal injury. Excessive use of cautery also decreases fine visualization of anatomical structures. APAs are also at risk of damage during completion of the anastomosis, particularly during placement of the anterior and lateral stitches. Great care should be taken here, and it is crucial to follow the curve of the needle during its placement to minimize APA puncture. In the event of this happening, the APA can usually be saved by exercising light compression or by watchful waiting. The surgeon should not panic and try to control the first impulse to fulgurate it. There is always time to coagulate or clip it. APA patency may be confirmed after completion of the watertight anastomosis with the aid of a laparoscopic Doppler probe. Apical APAs are sometimes more deceiving, as they always look as if they are going to pierce the

6 1234 european urology 51 (2007) Fig. 12 Apical APA giving off two collateral branches (dotted arrows). apex of the prostate instead of really taking a parallel course to the DVC, especially the small ones. We recommend dissecting them all the way around the DVC, and only fulgurate those branches clearly piercing the prostatic capsule. 4. Discussion Thanks to the advent of the laparoscopic technique, the urology community has seen a unique evolution in the surgical approach to the prostate. Although there is not enough evidence to answer the question of whether the laparoscopic approach meets the quality standards of open prostatectomy [7 9], laparoscopic radical prostatectomy (LRP), with or without robotic assistance, has gained remarkable popularity and is now widely implemented at specialized centres worldwide [10,11]. The video-endoscopic magnification lens has increased the view of the operating field 10- to 15-fold, enhancing our understanding of oftenunrecognized pelvic structures, such as APAs. This improved understanding is not only a function of lens magnification but also a consequence of a bloodless field provided by the tamponading effect of the pneumoperitoneum on the venous plexus. LRP series report an APA identification rate between 25% and 30%, which is somewhat higher than the 4% reported in the open prostatectomy series. APA preservation rates seem to be fairly similar [1 5]. Currently, no unequivocal link has been established between APA preservation and postsurgical functional outcomes, such as erectile function and continence. However, anatomical and retrospective clinical data suggest a possible connection [4]. In descriptive anatomy, the arterial supply to the penis is thought to originate from the internal pudendal artery alone; however, contemporary anatomic studies reveal a more complex network of arteries supplying the penis, and APAs play an important role [12,13]. The reported incidence of APAs is variable and seems to depend on the means used to identify them. Cadaveric dissection studies typically report an incidence as high as 70% [12], but the incidence falls to 7% [14] and 4% [4,5] in radiographic and open radical prostatectomy series, respectively. Breza et al. reported an incidence of 70% based on 10 cadaveric dissections [11]. In their study, all APAs originated from intrapelvic arteries, and in six of the seven cadavers with APAs, these arteries contributed to penile irrigation. In one case, the APA constituted the only blood supply to the left cavernous body. Similarly, Benoit et al. emphasized the contribution of APAs not only to cavernous body irrigation but also to urethral irrigation [12]. They found 33 APAs in 20 cadavers. The APAs originated from pelvic arteries in more than 80% of cadavers, and half of them branched from the inferior vesical artery. The APAs originating from inferior vesical arteries gave branches to the bladder, prostate, and external urethral sphincter. When these arteries were present, the main arterial supply of the urethral sphincter arose from them. After piercing the levator ani, the APAs usually gave multiple branches, 70% of which were cavernous arteries, usually destined for both corpora. In addition, when both internal pudendal arteries and APAs were present on the same side, anastomoses in the root of the penis occurred 70% of the time. As a result of these findings, there has been increasing emphasis on the role that APAs may play in erectile function and potency following pelvic surgery [4,14 19]. Besides neurologic causes, a vasculogenic etiology has been proposed for impotence following nerve-sparing radical prostatectomy [18,19]. Mulhall et al. retrospectively evaluated 96 patients with preserved preoperative erectile function who underwent bilateral, nerve-sparing surgery and did not receive pharmacological support for erectile dysfunction in the initial 12 mo after surgery [19]. Of these patients, 59% had some degree of arterial insufficiency as assessed by cavernosometry or penile ultrasonography. Only one-third of the patients with confirmed arterial insufficiency recovered erections suitable for penetration. Droupy et al. performed intraoperative transrectal colour Doppler studies on patients scheduled to

7 european urology 51 (2007) undergo radical retropubic prostatectomy [20]. Pharmacologically induced erections demonstrated that the haemodynamic changes in the pudendal and accessory pudendal arteries were similar to those described in the cavernous arteries, supporting the concept that APAs play a role in penile erection. More recently, Rogers et al. [4] compared patients who underwent nerve-sparing radical retropubic prostatectomy with concomitant preservation of large APAs to those who underwent surgery without arterial preservation. Vascular preservation more than doubled the probability of regaining potency, and the procedure was associated with a statistically significant shorter time to regain potency. In conclusion, because any connection between APA preservation and postsurgical functional outcomes are based on anatomical and retrospective clinical data, we must concede that the functional role of APAs is yet to be determined. Prospective studies are currently underway at our institution to address this question. Until answers to these questions are found, we believe that APA preservation should be part of modern radical prostatectomy, as it is not only feasible but also does not put the oncologic safety of the procedure at stake [1]. Acknowledgements The authors would like to thank Michael McGregor for his expert editorial review. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at doi: / j.eururo and via com. Subscribers to the printed journal will find the supplementary data attached (DVD). References [1] Secin F, Karanikolas N, Kuroiwa K, Vickers A, Touijer K, Guillonneau B. Positive surgical margins and accessory pudendal artery preservation during laparoscopic radical prostatectomy. Eur Urol 2005;48: [2] Secin F, Karanikolas N, Touijer K, Martinez Salamanca JI, Vickers A, Guillonneau B. Anatomy of accessory pudendal arteries in laparoscopic radical prostatectomy. J Urol 2005; 174: [3] Matin SF. Recognition and preservation of accessory pudendal arteries during laparoscopic radical prostatectomy. Urology 2006;67: [4] Rogers CG, Trock BP, Walsh PC. Preservation of accessory pudendal arteries during radical retropubic prostatectomy: surgical technique and results. Urology 2004;64: [5] Polascik TJ, Walsh PC. Radical retropubic prostatectomy: the influence of accessory pudendal arteries on the recovery of sexual function. J Urol 1995;154: [6] Guillonneau B, Vallancien G. Laparoscopic radical prostatectomy: the Montsouris technique. J Urol 2000;163: [7] Boccon-Gibod L. Radical prostatectomy: Open? Laparoscopic? Robotic? Eur Urol 2006;49: [8] Touijer K, Guillonneau B. Laparoscopic radical prostatectomy: a critical analysis of surgical quality. Eur Urol 2006;49: [9] Graefen M, Walz J, Huland H. Open retropubic nervesparing radical prostatectomy. Eur Urol 2006;49: [10] Rassweiler J, Stolzenburg J, Sulser T, Deger S, Zumbé J, Hofmockel G, et al. Laparoscopic radical prostatectomy: the experience of the German Laparoscopic Working Group. Eur Urol 2006;49: [11] Rassweiler J. Open vs. laparoscopic radical prostatectomy...and laparoscopy is better! Eur Urol 2006;50:26 8. [12] Benoit G, Droupy S, Quillard J, Paradis V, Giuliano F. Supra and infralevator neurovascular pathways to the penile corpora cavernosa. J Anat 1999;195: [13] Breza J, Aboseif SR, Orvis BR, Lue TF, Tanagho EA. Detailed anatomy of penile neurovascular structures: surgical significance. J Urol 1989;141: [14] Rosen MP, Greenfield AJ, Walker TG, Grant P, Guben JK, Dubrow J, et al. Arteriogenic impotence: findings in 195 impotent men examined with selective internal pudendal angiography. Radiology 1990;174: [15] Gray RR, Keresteci AG, St Louis EL, Grosman H, Jewett MA, Rankin JT, et al. Investigation of impotence by internal pudendal angiography: experience with 73 cases. Radiology 1982;144: [16] Bahren W, Gall H, Scherb W, Stief C, Thon W. Arterial anatomy and arteriographic diagnosis of arteriogenic impotence. Cardiovasc Intervent Radiol 1988;11: [17] Aboseif SR, Breza J, Orvis BR, Lue TF, Tanagho EA. Erectile response to acute and chronic occlusion of the internal pudendal and penile arteries. J Urol 1989;141: [18] Mulhall JP, Graydon RJ. The hemodynamics of erectile dysfunction following nerve-sparing radical retropubic prostatectomy. Int J Impot Res 1996;8:91 4. [19] Mulhall JP, Slovick R, Hotaling J, Aviv N, Valenzuela R, Waters WB, et al. Erectile dysfunction after radical prostatectomy: hemodynamic profiles and their correlation with the recovery of erectile function. J Urol 2002;167: [20] Droupy S, Hessel A, Benoit G, Blanchet P, Jardin A, Giuliano F. Assessment of the functional role of accessory pudendal arteries in erection by transrectal color Doppler ultrasound. J Urol 1999;162: