An Operative and Anatomic Study to Help in Nerve Sparing during Laparoscopic and Robotic Radical Prostatectomy
Introduction
More than 170,000 men in the United States were diagnosed with prostate cancer in 2002. The goal of effective cancer screening is to identify patients with more localized, and thus more potentially curable disease. Radical retropubic prostatectomy offers an effective cure [1], [2], [3], [4], but can be associated with postoperative morbidities, including erectile dysfunction and incontinence [5], [6], [7]. Sexual function can often be maintained by nerve sparing with the anatomic prostatectomy developed by Walsh [8], [9], [10] and others [11], [12], [13], [14], [15]. However, the results regarding potency preservation published in the literature by many centers are not satisfactory [5], [6], [7].
Many factors influence postoperative potency, including preoperative erectile function, patient age, extent of disease, experience of the surgeon, and anatomic variation. Identifying and sparing the neurovascular bundle (NVB) on one or both sides is crucial in maintaining erectile function. Several excellent monographs, textbooks, and artist drawn figures explaining the detailed course of the neurovascular bundles are available based on the initial anatomical dissections [8], [9], [10], [16], [17]. In recent years some centers are attempting nerve sparing anatomic prostatectomy using conventional and robotic-assisted laparoscopic approaches [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33]. The surgical steps for these minimally invasive approaches differ significantly from the conventional radical prostatectomy for which most existing anatomical descriptions have been done. Both laparoscopic and robotic approaches differ from open prostatectomy in terms of visualization, magnification, and most importantly, procedure steps. Laparoscopic and robotic prostatectomies are performed in an antegrade manner, while conventional radical retropubic prostatectomy is often performed in a retrograde manner (i.e. transection of the urethra prior to bladder neck disconnection from prostate).
A detailed anatomical map of the neurovascular bundles from the laparoscopic perspective is currently lacking. While artist drawn figures are adequate for the open surgery which benefits from both vision and tactile sense, they are not as useful during laparoscopic and robotic procedures because (a) they were not drawn with laparoscopic approach in mind and (b) the magnification and three-dimensional (3D) stereoscopic vision of robotic cameras actually require seeing these important structures through the lenses rather than surgical loupes or naked eye.
Therefore we undertook this anatomical study (with the help of an anatomist) to unravel the course of neurovascular bundles and superimposed the images on the intra-operative captures. Our goal was to develop a clear map to assist in the performance of nerve sparing laparoscopic or robotic radical prostatectomy, with good anatomical landmarks adapted for this new surgical approach.
Section snippets
Materials and methods
The data for this analysis was acquired by anatomic study of 12 fresh male cadavers of more than 50 years of age. The dissections were performed using laparoscopic camera, light source, video monitor and hand equipments (CIRCON ACMI™ Corporation). Later the courses of the nerves were further traced by open dissection using 2.5× surgical loops and an operating microscope. The nerve tissue was finally confirmed by histopathological studies.
The dissection was planned to mimic actual surgical
Results
The relationship between various anatomic structures is described herein.
Comments
Our study was undertaken to create a map of the NVB, with the goal to improve urologists’ understanding of pelvic anatomy from the new vantage point provided by the laparoscopic approach. Based on our dissection, the location of the pelvic plexus, course of the NVB and its relationship with seminal vesicle, lateral prostatic fascia and prostate were clearly identified. Keeping these relationships in mind, our discussion will now focus on the specific steps of a laparoscopic prostatectomy.
Most
Conclusion
Laparoscopic and robotic prostatectomies provide a view of the male pelvis not previously appreciated in open surgery. Vantage point, magnification, three-dimensional imaging, and improved hemostasis are all factors responsible for the better visualization encountered in laparoscopic and robotic prostatectomies. While logic dictates that a superior view should translate into the ability to perform a more meticulous dissection, unless surgeons are familiar with the new perspective provided by
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