Schematic axial view of prostatic fascial anatomy
The dissection plane will be guided by preoperative data: percentage of total number and length of positive core, data derived from MRI regarding extraprostatic extension, rectal examination, age of the patient and potency prior to surgery (IIEF5 score). We perform an antegrade approach for robot assisted radical prostatectomy (RARP) as previously described by other authors, with an interfascial nerve-sparing [1, 3, 5]. An experience assistant who is capable of aiding in exposure of the dissection planes is essential to successfully completing this step. Maintaining a bloodless surgical field and paying close attention to the prostatic contour will also aid in precise dissection of the bundles.
While maintaining an intact endopelvic fascia (EPF), the third arm robotic grasper retracts both SVs anteriorly while the assistant provides countertraction on the posterior aspect of the bladder wall in order to create vertical tension on the DF. This fascia is then incised horizontally just below its attachment to the posterior aspect of the prostate. The dissection starts medially in the reticular connective tissue underneath and follows the prostatic fascia (above) towards the apex, avoiding cautery in order to prevent rectal injury and preserve the apical neural components. DF is then retracted posteriorly by the assistant using gentle downward pressure and the dissection is extended laterally to the lateral pedicle fat pad proximally and to the vein distally that provides the land mark for the medial border of the NVB. The apical dissection will be continued after releasing NVB bilaterally in order to achieve greater mobility of the prostate and to securely dissect the posterior apex.
Control of the Lateral Pedicle
This is one of the most critical aspects of the procedure, and identification of the lateral edge of the prostate is the key for precise dissection. We begin by incising the EPF on the anterior aspect of the prostate at 2 o’clock on the right and at 10 o’clock on the left, from the puboprostatic ligament distally to the base proximally. We then open the avascular plane between the PF and the LAF on the lateral aspect of the prostate going from the incision towards the external aspect of the NVB. The robotic grasper lifts the prostate ventrally and laterally in the controlateral direction and the assistant gently retracts the bladder in order to stretch the pedicle and facilitating accurate exposure and subsequently division. The division of the pedicle is performed close to the prostate, Hemolock® clips are applied the proximally and the bipolar is used to control back bleeding from the prostate. This meticulous separation is necessary, because there is no clear border between the vessels and neural component.
Release of NVB
Once the prostate is freed from the vascular pedicle, it becomes more mobile and can be rotated to expose the triangle containing the NVB (Fig. 64.2). The exposure remains the same as previous step. It is important that the assistant retracts the bladder gently without creating any direct countertraction on the NVB. The interfascial plane is the plane between the NVB and the prostatic fascia. Here, irrigation and suction from the assistant can be useful in identifying the contour of the prostate. It is crucial to remain directly on the surface of prostatic fascia to avoid inadvertent capsular incision. Once this triangle leaves the prostate, the dissection appears very elegant and usually can be performed by gently pushing the prostate away from the NVB. The fixed placement of the robotic grasper is helpful at this point of the procedure preventing excessive traction on the NVB with blunt dissection. Transcapsular vessels are usually found on the way to the apex, they usually can be cut without any coagulation. The subsequent retraction of these small vessels generally stops the bleeding. The procedure is identical on the left side with the exception that the assistant maintains traction on the prostate, and the robotic grasper provides the gentle traction on the bladder. Once the release of the NVB is done laterally, we proceed with the release of the posterior aspect of the apex. This provides a safe landmark for the subsequent division of the urethra. It is important to avoid any electrocautery at the apex due to confluence of the NVB in this region and the adjacent sphincter. Furthermore the bleeding usually stops when the anastomosis is complete.