Periprostatic Anatomical Study And Clinical Application On Laparoscopic Radical Prostatectomy

Radical prostatectomy (RP) is the only primary treatment modality of localized prostate cancer (PC) that has proved its effectiveness against other ways. During the last three decades, the surgical treatment of prostate cancer has changed remarkably, The 3 main ways are open radical prostatectomy, laparoscopic prostatectomy and Robotic assistant prostatectomy. In our country, with all the urologists' hard working, we have had a quite large quantitative cases, many operative procedures have been standarded. What made the surgery progress were not only the new medical instruments but also the understanding of periprostatic anatomy. As Robert P. Myers said: In general surgeons who know the anatomy protect the patient by virtue of less blood loss, better margins of resection and greater functional preservation.The periprostatic anatomy is quite complicated. One aspect that is crucial to the understanding of the complex anatomy of the male pelvis is its significant individual variation. Some pelves are wide, making the prostate easily accessible, whereas other pelves are deep and narrow, complicating the access to the prostate particularly at the moment of performing a nerve-sparing surgery or a watertight urethrovesical reconstruction. The neurovascular structures surrounding the prostate may also vary from patient to patient, and the surgeon should be ready to understand those variations in order to tailor the surgical technique to the intraoperative findings Some anatomic structure have different names, Such as Dononvillier's fascia has at least the other 3 names:Rectovesical septum, prostaterectal fascia and rectogenital fascia.Though many patients get a quite long life span after the LRP operation, We still have a long way to go in order to give the patients a good urinary continence and erectile function. In the following studies, the regional anatomical observation on fixed cadaver, we will primarily focus on the understanding of the periprostatic fascial anatomy and the different extents of neurovascular bundle dissection in relation to the location and distribution of the cavernous nerves. Also, we provide an overview of the configuration of the urinary sphincter and its supporting structures. Then, we will study the operation skill in LRP.Chapter 1 Applied anatomy study on the LRP correlative periprostatic fasciaObjective:To study the periprostatic fascia relate to the LRP operation.Methods:1.24 fixed male cadavers with integrated pelvis were dissected and observed, The anatomical sequence was from the anterior aspect of the prostate to side, and then to rear. The observative emphasis were puboprostatic ligament, prostatic fascia, Denonvillier's fascia and pelvic fascia.2.4 organ specimen with bladder, seminal vesicles and prostate integrated after the laparoscopic radical resection of the bladder. The tissues between posterior wall of urinary bladder and seminal vesicles, the tissues between prostate and Denonvillier's fascia were studied.Results:1. The Denonvilliers' fascia has two layers:the fibromembranous anterior layer and the lipoid posterior layer. 2. Below ejaculatory ducts, the anterior layer are variety:15 cases (62.5%) like the leather,9 cases(37.5%) like the membrane; The frontier layer can be stripped from the surface of the prostate in 18(75%) case, Can not be stripped without damaged the gland tissue in 6(25%) cases. All the anterior layer tightly adhere to the rectourethral muscle in membranous urethra.3. The area below Douglas were divided into 2 loosened planes:"the gap behind seminal vesicles" and "the front gap of rectum".4. The interspace between prostatic between prostatic capsule and lateral fascia changed comparatively large, The interface was loosening in 14 cases and tightly contacted in 10 cases, the tight ones'fascia can not be dissected without prostate damaged.5. From lateral to anterior surface, the prostatic fascia can not be dissected from the capsule.6. The average breadth of the puboprostatic ligament in pubis part was 6.9mm, in prostate part was 12.5mm; the middle part was 5.3mm; the center was 2mm thick. The puboprostatic ligament composed of tough connective tissue.7. The puboprostatic ligament is not the only constitution contact pubis periosteum and urogenital system organs in the retropubic space. There are puborectal ligament upper and pubourethral ligament under the tough puboprostatic ligament.8. In the fresh specimen, prostate capsule can be dissected on the lateral surface.Conclusions:1. The interspace between prostate and the periprostatic fascia is changed, Along some plane can dissect swimmingly.2. On account of the demand of surgery, We need further anatomic study on the nerve and blood vessel between prostatic fascia and parietal pelvic fascia. Chapter 2 Applied Anatomic study on erection functional related nerveObjective:Based on the accuracy of the practical LRP and the idea of preserve NVB and CN utmostly, To clarify the correlated nerve anatomy.Methods:1.24 fixed male pelvic specimens were dissected and observed, The courser of the NVB below the Seminal Vesicles was noted, The distance between prostate and the NVB was measured.2.2 Integrity android pelvis, The nerve and blood before Sacrococcygeal vertebrae were visual studied.Results:1. The nerves running in the neurovascular bundle have two states:(1) The neurovascular bundle of the prostate descends along the postero-lateral border of the prostate, taper to the apex of prostate gland. This kind of circumstance happened in 16 cases; (2) The neurovascular bundle fall into two branches at the base of prostate, one branch run as (1), the other branch run to the front of the prostate, taper to apex of prostate gland at the lateral of the puboprostatic ligament. This kind of circumstance happened in 8 cases.2. The bilateral neurovascular bundles have the same distribution, that mean neurovascular bundles symmetric distributed.3. The posterior-lateral neurovascular bundle can be easily dissected. The anterior-lateral nerve adhered tightly to the capsule can not be separated easily.Conclusions:1. The neurovascular bundles have different distribution in different cases, This may cause a indefinite nerve preservation effect in some patients.2. Look the NVB as a independent nerve fascia layer structure, may make for the understanding of the relevantly structure. Chapter 3 Applied Anatomic study on urinary continence following LRPObjective: To investigate the relationship between some important urinary continence related anatomy and LRP.Methods:2 fixed male hemi-pelvises removal of the ilium were dissected and observed.Results:1. The apex of the prostate and membranous urethra were covered a pyknotic fibrous tissue membrane, this fascia transferred from superior fascia of pelvic diaphragm.2. The 3 to 5mm apex of the prostate and the below membranous urethra are surround by musculature with a thick anterior part and a weak posterior part, the musculature can be dissected easily.3. Simulated the operation of LRP, We found it was hard to cut the urethra perpendicularly without damage the musculature of the prostate apex.4. In a same specimen, the length of the anterior and posterior urethra above the pelvic diaphragm is not the same. Drag the prostate to anterosuperior, the urethra above pelvic diaphragm will be cut easily.Conclusions:We think the following technique make for urinary continence after LRP:1. Try to dissect Denonvilliers' fascia to the surface of musculus puborectalis along the surface of seminal vesicle and prostate; 2. Transect the urethra from rear to the anterior surface, Which may reserve enough urethra; 3. Drag the prostate to the headward will help to transect the urethra; 4. Sphincter around periprostate has different thickness in different part, Dissection bluntly the apex of prostate may refrain from damage the sphincter. Chapter 4 Anatomic study of Dorsal vein complex relate to LRPObjective: To explore the modus operandi in deal with Dorsal vein complex.Methods:2 fixed male pelvic specimens, Observed the puboprostatic ligament adhesive situation, cut the PL from upper to below from the midpiece, cut the lateral pelvic fascia, Press the prostate to rearward. Simulate the handling way in LRP, observe the effects.Results:1. The puboprostatic ligament has a large tension.2. The prostate superficial vein between the two PLs is quite long and large.3. Below the PL, It is impossible to distinguish the DVC even after push aside all the areolar tissue.4. The vein on anterior surface of the urethra has a loosening attach to urethra, but the fascia of DVC can not be dissected.Conclusions:The anatomy of DVC is quite complicated, transfixion way often used in LRP may not always safe.Chapter 5 Laparoscopic anatomic and Surgery skill study on LRPObjective:To observe the anatomical features of the LRP endoscopically in living bodies and find proper anatomical landmarks in LRP and provide the theory guidance for the LRP.Methods:The LRP of 16 prostate cancer were observed and analyzed. Emphasis observation the following component elements: 1. Set up extraperitoneal; 2.Pelvic cavity lymph nodes resection; 3.Resection of the neck of bladder and deal with the neck; 4. Dissociation of the seminal vesicle and Deferentia; 5. Dissociation of the Denonvilliers'fascia; 6. Dissection between fascia prostatae and parietal pelvic fascia;7. Deal with puboprostatic ligament; 8. Deal with DVC; 9. Deal with the apex of prostate and cut the urethra.Results:1.Pay attention to circumflex iliac vein and circumflex iliac artery.2.Resection of the bladder neck from anterolateral to frontal to posterior.3. It is relatively easy dissection along the gap in rear of Seminal Vesicles.4. It is easy to dissection along the gap of the two Denonvilliers'fascia layers, It is not always succeed before the anterior layer.5. Dissection though different plane have different NVB preservation level.6. Only part prostate fascia can be dissected from the surface of prostate during LRP7. We may deal with PL and DVC along the surface of prostate and need not transfixion of DVC.8. We may dissect the posterior wall prior to anterior wall of the urethra.Conclusions:Some steps of the LRP may have further improve.