Laparoscopic Lateral Pelvic Lymph Node Dissection ...

第 39 巻 第 12 号 2012 年 11 月

2173

Laparoscopic Lateral Pelvic Lymph Node Dissection for Lower Rectal Cancer: Initial Clinical Experiences with Prophylactic Dissection Shinsaku Obara＊1 Fumikazu Koyama＊1,2 Tadashi Nakagawa＊1 Shinji Nakamura ＊1,3 Takeshi Ueda＊1 Naoto Nishigori＊1 Takashi Inoue＊1 Keijiro Kawasaki ＊1 Takayuki Nakamoto＊1 Hisao Fujii＊2 and Yoshiyuki Nakajima ＊1 〔

 39 （12） : 2173 ─ 2175,

, 2012〕

Summary  Aim: To evaluate the technical feasibility of laparoscopic lateral pelvic lymph node dissection（LPLD）following total mesorectal excision（TME）as prophylaxis for patients with advanced lower rectal cancer but no radiologic evidence of lymph node involvement. Patients and methods: TME was performed on 30 patients with cT3N1─2M0 lower rectal cancer. LPLD was performed by laparoscopic surgery in 12 patients（LAP group），and open surgery in 18 patients（Open group）. Statistical analysis was used to compare the number of harvested lymph nodes, operative time, operative blood loss, transfusion rate, and volume of transfusion between the groups. Results: No significant difference was observed in the number of harvested lymph nodes. Operative time was significantly longer in the LAP group; however, operative blood loss, transfusion rate, and volume of transfusion were significantly lower in the LAP group. Conclusion: Laparoscopic LPLD, when performed by a well─trained laparoscopic team, is safe and feasible in some selected lower rectal cancer patients. This approach has the potential to achieve oncologic lymph node clearance equivalent to open surgical LPLD, and to overcome the cited disadvantages of LPLD, which include greater operative blood loss and urinary dysfunction. Key words: Rectal cancer, Lateral pelvic lymph node dissection, Laparoscopic surgery

Introduction  Lateral pelvic lymph node metastasis is observed in 10.6─25.5 ％ of advanced rectal cancer located below the peritoneal reflection1─3）. To improve local control and prolong patient survival, preoperative chemoradiotherapy has been introduced in western countries, and intraoperative lateral pelvic lymph node dissection （LPLD）is used in Japan. Recent studies have indicated that lateral pelvic side─wall recurrence is a risk in patients treated with preoperative chemoradiotherapy and curative resection4）. On the other hand, LPLD is reported to be accompanied by a prolonged operative time, increased blood loss, and subsequent genito─urinary dysfunction5）.  In the past decade, the laparoscopic surgical approach has gained wide clinical acceptance in the treatment of patients with colorectal cancer6,7）. This minimally invasive approach offers decreased surgical trauma, fewer perioperative complications, and faster postoperative recovery compared with conventional open surgery, with similar survival rates. The technique of laparoscopic LPLD for advanced rectal cancer has not

been widely practiced; there are only a few reports of its use8─10）. It is still unclear whether the laparoscopic LPLD is a safe and effective technique to evaluate for lateral pelvic lymph node metastases.  As our operator experience has accumulated, we have extended the indication for laparoscopic surgery to almost all stages of colorectal cancer. Since July 2009, we have selectively performed laparoscopic LPLD as prophylaxis for cT3 lower rectal cancer patients without evidence of lateral pelvic node metastasis on radiographic studies. In the present study, we report our initial experience performing laparoscopic TME with LPLD for advanced lower rectal cancer in a series of 12 consecutive patients. I. Patients and methods  Forty─three patients with lower rectal cancer underwent curative surgery, including LPLD, in our hospital between January 2007 and May 2012. It is our standard practice to perform LPLD for patients with rectal cancer located below the peritoneal reflection. We carried out laparoscopic TME with LPLD in 12 patients（LAP group）and conventional open surgery with LPLD in 31

＊1

 Dept. of Surgery, Nara Medical University  Dept. of Endoscopy and Ultrasound, Nara Medical University ＊3  Dept. of Chemotherapy, Nara Medical University ＊2

Corresponding author: Fumikazu Koyama, Department of Surgery and Department of Endoscopy and Ultrasound, Nara Medical University, 840 Shijo─cho, Kashihara City, Nara 634─8522, Japan

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patients（Open group） . Thirteen patients were excluded from the Open group, as their surgery required resection of adjacent organs. The Open group contained patients with both prophylactic dissection and therapeutic dissection. All patients in the LAP group underwent prophylactic dissection. We conducted laparoscopic LPLD based on the recommendations of the Japanese Classification of Colorectal Carcinoma, with extraction of lymph nodes located around the internal iliac vessels, and the obturator foramen. We compared the number of lymph nodes harvested from these 2 areas between the LAP group and the Open group. We also evaluated the operative factors of both groups: operative time, operative blood loss, transfusion rate, and volume of transfusion. The Mann─Whitney’ s test was used to compare the number of harvested lymph nodes, operative time, operative blood loss, and volume of transfusion. The transfusion rate was analyzed by Fisher s exact test. p values were considered statistically significant at 0.05 or less. II. Results  1. Comparative analysis of the lateral pelvic lymph nodes  Intraoperative view of a dissected LPLD is shown in Fig.1. Lymph nodes were collected from the internal iliac area and the area of the obturator foramen. The number of lymph nodes was evaluated separately, according to collection area and whether they came from the right and left side（Table 1a） . The median number of lymph nodes harvested from the right internal iliac area was 1.5（range, 0─13）in the LAP group, and 4.5 （range, 0─8）in the Open group（p＝0.073） . The median number of lymph nodes harvested from the left internal iliac area was 1.0（range, 0 ─3）in the LAP group, and 2.0（range, 0─11）in the Open group（p＝ 0.056） . In the right obturator area, the median number of lymph nodes was 7.5（range, 1─12）in the LAP group, and 9.0（range, 0─30）in the Open group（p＝ 0.268） . The median number of lymph nodes harvested from the left obturator area was 7.0（range, 1─12）in the LAP group, and 9.5（range, 0─20）in the Open group（p＝0.077） .  2. Analysis of operative factors  The median operative time was 678 minutes（range, 556─778 minutes）in the LAP group, and 517 minutes （range, 404 ─696 minutes）in the Open group（p＝ 0.001） . The difference between these 2 groups was statistically significant. The median operative blood loss was 155 mL（range, 10─613）in the LAP group, 1,217 mL（range, 391─2,240 mL）in the Open group; the amount of bleeding was significantly lower in the LAP group（p＜0.001） . As a result, the median volume of transfusion was 0 mL（range, 0─560 mL）in the LAP group, and 560 mL in the Open group（range, 0─1,120 mL） . This difference was statistically significant（p＝ 0.001） . The transfusion rate was 8.3％（1／12 patients） in the LAP group, and 66.7％（12／18 patients）in the Open group; ─this was significantly different（p＝ 0.002） （Table 1b）. No urinary dysfunction was observed post operatively in both groups. III. Discussion  Our study demonstrates that the laparoscopic approach to LPLD may be just as effective as conventional open surgery regarding oncologic clearance of lateral pelvic lymph nodes. It also shows the possibility of

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a b c

Fig. 1 a: Intraoperative view of a dissected LPLD with preservation of the vascular and nerve structures. b: Intraoperative view of a dissected left internal iliac area. c: Intraoperative view of a dissected left obturator area.

overcoming the previously cited disadvantages of LPLD, including greater operative blood loss and urinary dysfunction5）. Lateral pelvic lymph nodes can be dissected equally effectively by either conventional open surgery or the laparoscopic approach. This claim is supported by our results: there was no difference in the number of retrieved lymph nodes from each location between the laparoscopic approach and open surgery. The total number of retrieved lateral pelvic lymph nodes by our laparoscopic series（median, 17） was similar to that by Sugihara, （median, 17），a study produced by the Centers of Excellence Program in Japan11）. Notably, in our prophylactic dissection cases where preoperative radiographic studies had shown no evidence of positive lateral pelvic lymph nodes, 1 of 12 patients（8.3％）in the laparoscopic surgery group and of patients（11.1％）in the open surgery group had positive lateral lymph node metastases on final pathology.  The operative blood loss in the laparoscopic group （median, 155 mL）was significantly reduced compared with that in the open surgery group（median, 1,217 mL） . The amount of blood loss for laparoscopic TME and LPLD together（155 mL），was less than that previously reported for TME alone in open surgery（375 12） mL） . Previous reports have also shown the benefit of laparoscopic LPLD in minimizing operative blood loss （25─188 mL）by facilitating precise dissection under magnified clear vision8─10）.  We were able to protect the autonomic nerve plexus in all laparoscopic LPLD patients, which succeeded in preserving urinary function in all cases（data not shown）. In previous reports, citing urinary dysfunction as a complication of this procedure, many cases were performed unilaterally, after preoperative chemoradiotherapy8─10）. As the contralateral pelvic nerve plexus was not involved in surgery, it cannot be determined that the effect on urinary function was a direct result of laparoscopic LPLD. In our series, all patients received bilateral LPLD without any preoperative treatment. Therefore, our data indicate that urinary function may be preserved by laparoscopic LPLD with protection of the pelvic plexuses.  The operative time required for bilateral laparoscop-

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第 39 巻 第 12 号 2012 年 11 月

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Table 1 a: The median number of lymph nodes harvested from each area.  No significant difference was observed between the 2 groups. Lymph node area Rt─internal iliac area Lt─internal iliac area Rt─obturator area Lt─obturator area

LAP group（n＝12）

Open group（n＝18）

p value

1.5（0─13）

4.5（0─8）

0.073

1.0（0─3）

2.0（0─11）

0.056

7.5（1─12）

9.0（0─30）

0.268

7.0（1─12）

9.5（0─20）

0.077

b: Operative time was significantly longer in the LAP group. Operative blood loss, volume of transfusion, and transfusion rate were significant lower in the LAP group. Operative factors

LAP group（n＝12）

Operative time（min） Operative blood loss（mL）

678（556─778） 155（10─613）

Volume of transfusion（mL） Transfusion rate（％）

   0（0─560） 8.3     

ic LPLD was quite long, reaching to 200 minutes. Although our laparoscopic team is still on the learning curve for laparoscopic LPLD, it cannot be denied that this is a very complex procedure, even with the magnified clear vision of laparoscopy aiding precise dissection. This procedure should be performed by a well─ trained laparoscopic team familiar with open surgical LPLD. Conclusion  Despite of a retrospective study with a small number of patients, our present study indicates that laparoscopic LPLD, when performed by a well─trained laparoscopic team, is safe and therefore feasible for some lower rectal cancer patients. The laparoscopic approach is able to achieve oncologic lymph node clearance equal to that of open surgery. We did not observe the previously cited disadvantages of LPLD: greater operative blood loss and urinary dysfunction. In fact, we observed quite the opposite. Laparoscopic LPLD had a lower blood loss, transfusion rate, and transfusion volume compared with open surgery, although those benefits did come with the disadvantage of a longer operative time. References 1）Ueno H, Mochizuki H, Hashiguchi Y, : Prognostic determinants of patients with lateral nodal involvement by rectal cancer.  234 （2） : 190─197, 2001. 2）Kusters M, Beets GL, van de Velde CJ, : A comparison between the treatment of lower rectal cancer in Japan and the Netherlands, focusing on the patterns of local recurrence.  249 （2） : 229─235, 2009. 3）Yano H and Moran BJ: The incidence of lateral pelvic side─wall nodal involvement in low rectal cancer may be similar in Japan and the West.  95（1） : 33─49, 2008. 4）Kim TH, Jeong SY, Choi DH, : Lateral lymph node

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Open group（n＝18）

p value

517（404─696）   

0.001

1,217（391─2,240） 560（0─1,120）   66.7       

＜0.001 0.001 0.002

metastasis is a major cause of locoregional recurrence in rectal cancer treated with preoperative chemoradiotherapy and curative resection.  15 （3） : 729─737, 2008. 5）Georgiou P, Tan E, Gouvas N, : Extended lymphadenectomy versus conventional surgery for rectal cancer: a meta─analysis.  10 （11） : 1053─1062, 2009. 6）Buchanan GN, Malik A, Parvaiz A, : Laparoscopic resection for colorectal cancer.  95 （7）:893─ 902, 2008. 7）Neudecker J, Klein F, Bittner R, : Short─term outcomes from a prospective randomized trial comparing laparoscopic and open surgery for colorectal cancer.  96 （12） : 1458─1467, 2009. 8）Konishi T, Kuroyanagi H, Oya M, : Multimedia article. Lateral lymph node dissection with preoperative chemoradiation for locally advanced lower rectal cancer through a laparoscopic approach.  25（7）: 2358─2359, 2011. 9）Park JS, Choi GS, Lim KH, : Laparoscopic extended lateral pelvic node dissection following total mesorectal excision for advanced rectal cancer: initial clinical experience.  25 （10） : 3322─3329, 2011. 10）Liang JT: Technical feasibility of laparoscopic lateral pelvic lymph node dissection for patients with low rectal cancer after concurrent chemoradiation therapy.  18 （1） : 153─159, 2011. 11）Sugihara K, Kobayashi H, Kato T, : Indication and benefit of pelvic sidewall dissection for rectal cancer.  49 （11） : 1663─1672, 2006. 12）Fujita S, Yamamoto S, Akasu T, : Lateral pelvic lymph node dissection for advanced lower rectal cancer.  90 （12） : 1580─1585, 2003.  本論文の要旨は第 34 回日本癌局所療法研究会において発表 した。

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