The "peritoneal scaffold" technique of extended pelvic lymph node dissection during radical prostatectomy: A novel technique

Chiruvella Mallikarjuna; Prasant Nayak; Syed Mohammed Ghouse; K Purnachandra Reddy; Deepak Reddy Ragoori; MT Bendigeri; Siva Reddy

doi:10.4103/0970-1591.189722



SURGICAL CRAFT

Year : 2016 \| Volume : 32 \| Issue : 4 \| Page : 310-313

The "peritoneal scaffold" technique of extended pelvic lymph node dissection during radical prostatectomy: A novel technique

Chiruvella Mallikarjuna, Prasant Nayak, Syed Mohammed Ghouse, K Purnachandra Reddy, Deepak Reddy Ragoori, MT Bendigeri, Siva Reddy
Department of Urology, Asian Institute of Nephrology and Urology, Hyderabad, Telangana, India

Date of Web Publication

28-Sep-2016

Correspondence Address:
Dr. Prasant Nayak
Asian Institute of Nephrology and Urology, Erramanzil Colony, Somajiguda, Hyderabad - 500 082, Telangana
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/0970-1591.189722

Abstract

Introduction: Laparoscopic or robotic-assisted laparoscopic radical prostatectomy (RALP) is a frequently used approach for localized carcinoma prostate. For intermediate and high-risk cancers, extended pelvic lymph node dissection (e-PLND), is often performed. Conventional e-PLND involves piecemeal retrieval of lymphatic tissue. We describe a novel technique of laparoscopic e-PLND, which involves en-masse removal of pelvic lymph nodes from each side, based on an overlying peritoneal scaffold.
Materials and Methods: Fifteen cases of intermediate and high-risk carcinoma prostate underwent laparoscopic radical prostatectomy (LRP) with peritoneal scaffold based e-PLND within a period of 1 year. We describe the surgical techqniue and outcomes in terms of operative time and lymph nodes retrieved.
Results: The mean operating times for "peritoneal scaffold" lymphatic dissection was 48 min (38-64). The total number of lymph nodes retrieved was 18 (14-22). There were no cases with postoperative lymph collection or hematoma.
Conclusion: The "peritoneal scaffold" technique of e-PLND is a novel technique, which involves having a peritoneal scaffold to bind and hold all the lymphatic tissues together in its anatomical orientation during dissection. This enables complete retrieval of specimen during LRP and RALP.

Keywords: Carcinoma prostate, extended pelvic lymph node dissection, laparoscopic pelvic lymph node dissection, radical prostatectomy

How to cite this article:
Mallikarjuna C, Nayak P, Ghouse SM, Reddy K P, Ragoori DR, Bendigeri M T, Reddy S. The "peritoneal scaffold" technique of extended pelvic lymph node dissection during radical prostatectomy: A novel technique. Indian J Urol 2016;32:310-3

How to cite this URL:
Mallikarjuna C, Nayak P, Ghouse SM, Reddy K P, Ragoori DR, Bendigeri M T, Reddy S. The "peritoneal scaffold" technique of extended pelvic lymph node dissection during radical prostatectomy: A novel technique. Indian J Urol [serial online] 2016 [cited 2023 Apr 2];32:310-3. Available from: https://www.indianjurol.com/text.asp?2016/32/4/310/189722

Introduction

Extended pelvic lymph node dissection (e-PLND) is an accepted method of performing pelvic lymphadenectomy during radical prostatectomy for intermediate and high-risk carcinoma prostate. ^[1],[2] The procedure entails removal of pelvic lymphatic tissue between the genitofemoral nerve laterally and the bladder medially, from the inguinal ligament caudally to the ureteral crossing of common iliac vessels cranially and till the internal iliac vein in the depth, which lies deeper than the obturator nerve. ^[1] The traditional method involves a thorough dissection and removal of all fibrofatty tissue within these boundaries. More often than not, it ends up as a piecemeal retrieval of lymph nodes from this area. During laparoscopy, this would mean multiple attempts at retrieval of these nodes with the risk of these loose pieces getting lost within the peritoneal cavity. Furthermore, it becomes difficult to map these lymph nodes to their respective nodal groups after retrieval in a piecemeal fashion.

We describe a novel laparoscopic technique of e-PLND using a "peritoneal scaffold" dissection which effectively counters these drawbacks of the traditional surgical technique.

Materials and methods

Fifteen cases of intermediate and high-risk carcinoma prostate underwent laparoscopic radical prostatectomy (LRP) and the novel "peritoneal scaffold" technique of laparoscopic e-PLND between September 2014 and August 2015.

Technique

After obtaining a traditional 4-port or 5-port laparoscopic access for LRP with the patient in a steep Trendelenburg's position, e-PLND is begun by outlining the peritoneal triangle over the area of interest [Figure 1]a. The sides of the peritoneal triangle on each side are the lateral border of external iliac artery laterally; the medial side formed by the lie of the ureter, tracing that line further along the bladder wall until the vas deferens which forms the base of the triangle caudally. The apex of the triangle is at the level of ureteral crossing of the common iliac vessels, which also forms the cranial extent of the e-PLND. The apex is marked with a Hem-o-lok clip to help orient and map the lymph nodal mass after retrieval.

Figure 1: (a) Boundaries of the peritoneal scaffold (u = Ureter, v = Vas, a = External iliac artery). (b) After lateral dissection (ia = External iliac artery, iv = External iliac vein, o = Obturator nerve). (c) After medial dissection (ia = External iliac artery, iv = External iliac vein, u = Ureter, ua = Obliterated umbilical artery)

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The initial incisions of this triangular peritoneal scaffold are made on both the lateral sides. The boundaries of lymph node dissection remain the same as for a standard e-PLND, namely, the genitofemoral nerve laterally, the bladder medially, the internal iliac vein inferiorly, and the inguinal ligament caudally. The lateral incision is deepened first, and the fibrofatty tissue with lymph nodes and lymphatics is rolled in from the genitofemoral nerve toward the peritoneal scaffold. The lymphatic tissue is dissected off the iliac vessels with a split and roll technique, maintaining its continuity with the scaffold above [Figure 1]b. The dissection is deepened, and the obturator nerve and internal iliac vein are similarly bared off lymphatic tissue by employing a split and roll technique. The medial incision is then deepened, and the fat and lymphatic tissue is swept laterally toward the peritoneal scaffold. The obliterated umbilical artery is generally encountered here and is clipped and cut [Figure 1]c. Smaller branches of the internal iliac artery, if encountered, are clipped and cut, and swept up into the "peritoneal scaffold." The terminal branches of these vessels form the web and maintain the en-masse' integrity of the lymphatic tissue within the "peritoneal scaffold." The dissection proceeds caudally until the base of the triangle is reached. The two sides of the peritoneal scaffold are joined along the line of vas deferens which forms the base of the triangle. The peritoneal incision along the vas is deepened lateral to medial, and the lymphatic tissue is cleared from the inguinal ligament laterally and the bladder medially, drawing the tissue into the scaffold again [Figure 2]a. The distal part of the obliterated umbilical artery is encountered here and is clipped and cut.{Figure 2}

The lymphatic tissue thus gathered was then retrieved en-masse' attached to the "peritoneal scaffold" above [Figure 2]b. This en-masse' retrieval obviates the need for repeated change of instruments and multiple attempts at retrieval of lymphatic tissue as is done during conventional piecemeal removal. It also decreases the chances of losing the dissected lymphatic tissue and allows for excellent safe keeping of the material till its retrieval at the end along with the radical prostatectomy specimen [Figure 2]c. The Hem-o-lok clip placed at the apex of the triangle helps to orient and map the lymphatic tissue under the scaffold.

All patients had a 22 Fr drain kept in the Retzius' space which was removed once the drain output decreased to under 20 mL/day. All patients underwent postoperative ultrasonography (USG) abdomen and pelvis before discharge. Patients underwent a cystogram on postoperative day 14 before catheter removal. A USG abdomen and pelvis was done as a matter of routine in all cases, 3 months after surgery.

Results

The mean age of the patients was 63.7 years (52-69), the mean preoperative PSA being 14.8 ng/mL (9-32). All of them had a preoperative transrectal ultrasound-guided prostatic biopsy proven adenocarcinoma of the prostate, the Gleason scores ranging from 6 to 9. All the patients had a radionuclide bone scan, which was negative for metastases.

The mean operating time for lymphatic dissection was 48 min (38-64). The total number of lymph nodes retrieved from both the sides was 18 (14-22). One case had an external iliac vein injury during split and roll dissection of lymphatic tissue around the iliac vessels. That was managed by intraoperative laparoscopic suturing. In only one patient, the lymphatic packet from the left side "fractured" and had to be removed in two pieces. This could be because of the presence of the sigmoid mesentery on the left side which occasionally compromises the delineation of the scaffold on the left side.

The drain was removed on postoperative day 4 (3-7) once the output reduced to <20 mL. There were no cases with postoperative lymph collection, urinoma, or hematoma in our series at 3 months review USG.

Discussion

e-PLND is currently the best prognosticating tool in a case of carcinoma prostate undergoing radical prostatectomy with curative intent. ^[3] Lymph node mapping studies have shown that the prostate drains primarily into the obturator and external iliac lymph nodal groups. ^[4] However, sentinel lymph node mapping studies have shown that in addition to the above, lymphatic drainage also occurs to the internal iliac nodes. ^[4] e-PLND allows for the removal of lymph nodes from all these landing sites. It also yields a higher number of lymph nodes when compared to the conventional lymph node dissection. ^[1] Increasing the yield of lymph nodes and doing a thorough dissection from all possible landing sites increases the prognostic value of the lymph node dissection, as well as contributing to a higher recurrence-free survival in these patients. ^[1]

The anatomical extent of the e-PLND involves clearing of the lymph nodes on the external iliac artery and vein, the nodes within the obturator fossa and the nodes along the internal iliac artery. Some advantage has been reported in extending the dissection till the ureteral crossing of the common iliac vessels. ^[4]

The "peritoneal scaffold" technique of doing e-PLND adheres to the above boundaries, ensuring a thorough dissection and removal of lymph nodes from these regions. It also ensures a thorough bagging and retrieval of the nodal specimen during laparoscopy, as the entire lymph nodal mass is bound together onto the overlying peritoneal scaffold. The lymph nodal yield of 14-22 is as good, if not better than the reported conventional lymphadenectomy yield. ^[3]

Our novel technique also ensures a more complete removal of lymphatic tissues as opposed to a piecemeal removal. This is because the tissues are not teased away but are rather removed in continuity with the scaffold. Furthermore, a piecemeal laparoscopic removal has a chance that a few pieces might be lost in the peritoneal cavity which does not happen with a scaffold-based removal of lymph nodes.

Some authors have reported a higher rate of complications with e-PLND as compared to conventional PLND. ^[5] Most of these complications are lymphoceles (10%). We did not see any lymphocele in our case series. A subgroup analysis in a study of robotic-assisted LRP demonstrated no lymphocele in transperitoneal e-PLND as compared to an incidence of 19% lymphoceles in extraperitoneal e-PLND. ^[6] The transperitoneal approach and the spontaneous marsupialization of the cavity happening due to the removal of the peritoneal triangle, probably accounts for the lack of any lymphoceles in our series.

Conclusion

The "peritoneal scaffold" technique of e-PLND is a novel technique which involves having a peritoneal scaffold to bind and hold all the lymphatic tissues together in its anatomical orientation during dissection. This eases specimen entrapment and ensures a complete retrieval of specimen during laparoscopic or robot-assisted LRP. The peritoneal scaffold technique is an effective modification of the conventional e-PLND with inherent advantages and should be further evaluated in comparative studies against the conventional laparoscopic e-PLND technique.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Abdollah F, Gandaglia G, Suardi N, Capitanio U, Salonia A, Nini A, et al. More extensive pelvic lymph node dissection improves survival in patients with node-positive prostate cancer. Eur Urol 2015;67:212-9.
2.	Ji J, Yuan H, Wang L, Hou J. Is the impact of the extent of lymphadenectomy in radical prostatectomy related to the disease risk? A single center prospective study. J Surg Res 2012;178:779-84.
3.	Heidenreich A, Ohlmann CH, Polyakov S. Anatomical extent of pelvic lymphadenectomy in patients undergoing radical prostatectomy. Eur Urol 2007;52:29-37.
4.	Mattei A, Fuechsel FG, Bhatta Dhar N, Warncke SH, Thalmann GN, Krause T, et al. The template of the primary lymphatic landing sites of the prostate should be revisited: Results of a multimodality mapping study. Eur Urol 2008;53:118-25.
5.	Briganti A, Chun FK, Salonia A, Suardi N, Gallina A, Da Pozzo LF, et al. Complications and other surgical outcomes associated with extended pelvic lymphadenectomy in men with localized prostate cancer. Eur Urol 2006;50:1006-13.
6.	Ploussard G, Briganti A, de la Taille A, Haese A, Heidenreich A, Menon M, et al. Pelvic lymph node dissection during robot-assisted radical prostatectomy: Efficacy, limitations, and complications-a systematic review of the literature. Eur Urol 2014;65:7-16.