Laparoscopic Lymph Node Dissection Research Articles

Determining local-regional extension of prostate cancer

Prostate cancer evaluation and staging are based on the findings of clinical, radiological, and pathological studies. There has been a significant change in the type and availability of evaluative procedures in recent years. To summarize the current status of staging procedures, the role of computed tomography (CT), magnetic resonance imaging (MR), transrectal ultrasound (TRUS), lymph node dissection, and lymphangiogram in determining the extent of local and regional prostate cancer will be reviewed. CT has little utility in the assessment of local extension and is hampered in evaluating lymphatic metastasis because of a low sensitivity. However, CT is useful for radiotherapeutic treatment planning MR may provide better local disease assessment than TRUS, but TRUS is conducive to directed biospy of abnormalities. The role of laparoscopic lymph node dissection is expanding and early data seems to indicate that the procedure is similar to the more traditional procedure regarding the extent of anatomic dissection and number of lymph nodes removed for pathological examination. Stage migration occurs as staging procedures evolve and the proper role of staging procedures for prostate cancer must be considered to be a dynamic process, continually open for discussion and re-evaluation.

Round Table: “Comparison between laparoscopy-surgery in pelvic lymphadenectomy” - Introduction

Pelvic lymphadenectomy is a staging procedure for most urologists. It is therefore limited to the lymph nodes that can be approached in the easiest and least dangerous way. The dissection generally removes the lymph nodes situated below the bifurcation of the common iliac arteries; lymphatic drainage from bladder and prostate is also directed to pre-sacral nodes. As the main aim of lymphadenectomy is staging with minimal discomfort for the patient, the laparoscopic technique is clearly the most well-suited for this purpose. In the round table we will discuss the main features of “open” and laparoscopic lymph node dissection.

Histological Assessment of Lymph Node Metastases in Staging Lymphadenectomy for Prostate Cancer

Pelvic lymph node involvement in 44 patients with histologically confirmed prostatic carcinoma was assessed by open lymphadenectomy (24 patients) or laparoscopic lymph node dissection (20 patients). With open lymphadenectomy, node metastases were diagnosed on frozen section prior to radical surgery, in only 2 out of 7 patients. With laparoscopic dissection, metastases were correctly diagnosed in 6 out of 7 patients; one, however, was missed. Reasons for missing node metastases lie in the difficulty of recognizing nodes harboring carcinoma on gross examination. Indeed, metastases are often small and do not significantly alter the macroscopic appearence of the involved lymph node.

Laparoscopic Pelvic Lymph Node Dissection for Superficial Bladder Cancer

The Authors propose a new approach to the diagnosis and treatment of superficial bladder cancer. They focus on T1–G2 multifocal tumours and T1–G3, also if monofocal, that have a high incidence of lymph node involvement. In these cases, they perform pelvic laparoscopic lymph node dissection, thus obtaining an accurate diagnosis with a minimally invasive technique.

The Contemporary Incidence of Lymph Node Metastases in Prostate Cancer: Implications for Laparoscopic Lymph Node Dissection

The incidence of lymphatic metastases in 229 consecutive patients with clinically localized prostatic cancer was assessed. Only 13 patients had nodal metastases, for an incidence of 5.7%. A monoclonal prostatic specific antigen value of more than 40ng./ml. correlated with a positive predictive value of 53% for nodal metastases. Routine laparoscopic node dissection is unnecessary considering the low incidence of nodal metastases.

Complications of Laparoscopic Pelvic Lymph Node Dissection

Intraoperative and postoperative complications were assessed in the first 372 patients undergoing laparoscopic pelvic lymph node dissection at 8 medical centers. In 16 patients laparoscopic node dissection could not be completed due to patient body habitus or technical difficulties. Of these aborted procedures 14 occurred during the initial 8 dissections at each institution. A total of 55 complications (15%) occurred: 14 were noted in the intraoperative and 41 in the postoperative period. Of these patients 13 required open surgical intervention for the treatment of a complication. Complications included vascular injury (11 patients), viscus injury (8), genitourinary problems (10), functional/mechanical bowel obstruction (7), lower extremity deep venous thrombosis (5), infection/wound problem (5), lymphedema (5), anesthetic complications (2) and obturator nerve palsy (2). Based on our experience, there is a significant learning curve associated with performing laparoscopic pelvic node dissection. However, with experience and adherence to laparoscopic surgical principles, the risk of complications may be minimized.

Initial Experience with Staging Laparoscopic Pelvic Lymphadenectomy Performed at the Time of Radical Retropubic Prostatectomy for Prostatic Adenocarcinoma

Laparoscopic pelvic lymphadenectomy on 47 consecutive patients at the time of radical retropubic prostatectomy for adenocarcinoma was performed to assess the adequacy of laparoscopic node dissections and the feasibility of performing such laparoscopic lymphadenectomy concomitantly with radical prostatectomy. Nodal packets were obtained laparoscopically bilaterally and sent for pathologic examination separately from any surgically obtained nodes. The average number of nodes obtained during laparoscopy was 10 ± 7.04. As operator experience improved, the number of nodes increased to an average of 11.6 for the last ten node dissections. Likewise, the number of nodes remaining after laparoscopic lymph node dissection fell progressively to an average of 1.7 during the last ten lymphadenectomies. In the preceding 30 standard pelvic lymphadenectomies performed by the authors (control series) an average of 13.4 ± 6.72 nodes were removed surgically prior to radical prostatectomy. There were no positive nodes found at the time of surgical exploration that had been missed by laparoscopic dissection (false negative). Two of forty-five patients had positive nodes at the time of laparoscopic dissection, and 1 of 30 control patients had positive nodes at the time of surgical dissection. Average daily wound drainage was significantly higher in laparoscopy patients, and there was a significant increase in the mean operative time in the laparoscopy group (226 v 147 minutes). However, rapidity improved with experience, and the average total time for the last ten laparoscopic lymph node dissections was 78 minutes. The average total operative time for laparoscopic lymph node dissection and prostatectomy was 208 minutes, v an average for the control cohort of 154 minutes. The hospital stay was been significantly different for the laparoscopic group. Laparoscopic pelvic lymphadenectomy appears to be an appropriate option for staging prostatic adenocarcinoma, with production of adequate node packets. The authors are refining criteria for the routine performance of this procedure.

Prostatic cancer

Despite the controversies in management for all stages of prostatic cancer, guidelines are emerging that allow for better selection of treatments for individual patients. For early stage disease, prostate-specific antigen determinations in conjunction with other staging procedures have refined our ability to define truly organ-confined disease. The more widespread use of laparoscopic lymph node dissections has spared many patients needless laparotomies. For patients with metastatic disease, the overall effect of potency-sparing antiandrogens as monotherapy needs to be investigated. Most encouraging is that more groups are using prostate-specific antigen changes to assess disease activity and the rapid translation of recent laboratory investigations into the clinic. As our ability to predict the biologic potential of an individual patient's tumor is improved, more individualized treatment recommendations will be possible.

Laparoscopic Pelvic Lymph Node Dissection: Assessment of Intraoperative and Early Postoperative Complications

We report the significant intraoperative and early postoperative complications that occurred in 6 of our first 42 patients undergoing laparoscopic lymph node dissection (14%). The intraoperative complications were unintentional cystotomy and inability to enter the peritoneum. The early postoperative complications were deep venous thrombosis necessitating readmission (two patients), partial obturator nerve injury in one patient, and retroperitoneal abscess in one patient. It is our opinion that the complication rate of laparoscopic pelvic lymph node dissection will decrease as we gain more experience with this procedure.

Pelvic Trainer for Laparoscopic Pelvic Lymph Node Dissection

Using commonly available materials, a pelvic trainer useful in refining hand-eye coordination can be assembled. Simulated arteries, veins, nerves, and lymph nodes help the surgeon gain confidence in the anatomic relations seen during pelvic laparoscopic node dissection. The techniques of dissection, clipping, and cutting can all be practiced in a simulated surgery without the need for a live animal model.

Correlation between side of palpable tumor and side of pelvic lymph node metastasis in clinically localized prostate cancer

Of 411 patients with palpable but clinically localized (Stages B or C) adenocarcinoma of the prostate, 100 (24.3%) were found at complete bilateral pelvic lymphadenectomy to have one or more lymph nodes positive for metastasis. These patients were divided into five subgroups on the basis of the location of the palpable tumor at digital rectal examination: left side only, left predominantly, both sides, right side predominantly, or right side only. Among 35 patients with positive nodes and a palpable tumor limited to one side of the prostate (clinically unilobar), metastases were found in the ipsilateral pelvic lymph nodes in 29 (83%). Only 6 (17%) of the patients had contralateral metastasis alone. A unilateral pelvic lymphadenectomy (ipsilateral to the side of the largest palpable tumor, or on either side if the tumor were bilateral) would have detected 80% of the patients with positive lymph nodes, with a positive predictive value of 100% and a negative predictive value of 94%. Lymph node metastases in patients with clinically localized palpable prostate cancer are most likely to be found on the same side as the palpable tumor and are considerably less likely to be found on the contralateral side alone. If frozen section examination of lymph nodes or laparoscopic lymph node dissection is planned before definitive therapy for prostate cancer, the pelvic lymph nodes ipsilateral to the side of the palpable tumor should be removed first.

New laser delivery device for laparoscopic procedures

A new device to facilitate laser delivery and improve mechanical advantage during surgical procedures is described. In the device, a quartz fiber is used to transmit laser energy to a forked metal tip. The utility of the device was assessed in five pigs. In three pigs a laparoscopic cholecystectomy was performed and in two pigs a laparoscopic lymph node dissection was performed. Advantages of the device included reduced smoke, clearer dissection planes, tactile feedback, and excellent mechanical advantage when used for blunt dissection. The device was qualitatively superior to both sculpted tip quartz fibers and electrocautery.