Original Article Japanese Journal of Clinical Oncology Advance Access published December 22, 2009 Jpn J Clin Oncol 2009 doi:10.1093/jjco/hyp172 Extraperitoneal Approach Induces Postoperative Inguinal Hernia Compared with Transperitoneal Approach after Laparoscopic Radical Prostatectomy Shunsuke Yoshimine, Akira Miyajima *, Ken Nakagawa, Hiroki Ide, Eiji Kikuchi and Mototsugu Oya Department of Urology, Keio University School of Medicine, Shinjuku, Tokyo, Japan *For reprints and all correspondence: Akira Miyajima, Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. E-mail: akiram@sc.itc.keio.ac.jp Received September 29, 2009; accepted November 16, 2009 Objective: The aim of this study was to determine the incidence and risk factors of postoperative inguinal hernia and to investigate whether the difference of approach could induce postoperative inguinal hernia after laparoscopic radical prostatectomy. Methods: We reviewed 493 consecutive patients who underwent laparoscopic radical prostatectomy from November 2000 to November 2007, and evaluated various preoperative parameters, specifically age, prostate-specific antigen (ng/ml), body mass index (kg/m 2 ), prostate volume (ml), previous major abdominal surgery, previous appendectomy, previous inguinal hernia repair and laparoscopic approach as risk factors for postoperative inguinal hernia. Results: Inguinal hernia occurred in 4 (4.9%) of the 81 patients in the transperitoneal approach group, and in 37 (9.0%) of the 412 patients in the extraperitoneal approach group. The overall incidence of inguinal hernia was 8.3% (41 of 493 patients). The median inguinal hernia-free survival time was 35 months and 6 months in the transperitoneal approach and extraperitoneal approach groups, respectively. Inguinal hernia developed within 2 years after surgery in 2 (50%) of 4 patients in the transperitoneal approach group, in 34 (91.9%) of 37 patients in the extraperitoneal approach group, for a total of 36 (87.8%) of 41 patients overall. Multivariate analysis showed that the extraperitoneal approach was a significant risk factor (P ¼ 0.043) for inguinal hernia. Conclusions: Inguinal hernia is a frequent complication after laparoscopic radical prostatectomy, and the incidence of inguinal hernia is greater with the extraperitoneal approach than with the transperitoneal approach. Key words: inguinal hernia radical prostatectomy laparoscopy extraperitoneal approach INTRODUCTION An inguinal hernia (IH) that develops after open radical retropubic prostatectomy (RRP) is a frequent complication with an incidence of more than 10% [range 12 19% (1,2)]. The first report of an IH after RRP was described by Regan et al. in 1996 (2). Since then, several other reports have been published. Regan et al. (2) also reported that prolonged stretching of the rectus and lower abdominal musculature and fascia following the use of self-retractors weakens the shutter valve mechanism of the internal hernia ring. Abe et al. (3) reported that previous abdominal surgery did not contribute to the development of an IH after RRP and concluded that undergoing the operation itself for prostate cancer was a risk factor compared with radiation therapy. Another report showed that a previous IH, wound-related problems, postoperative anastomosis stricture and low body mass index (BMI) were risk factors for a postoperative IH (4,5). At present, some risk factors are candidates for the # The Author (2009). Published by Oxford University Press. All rights reserved.
Page 2 of 5 Lap-prostatectomy and inguinal hernia development of an IH. IHs occur at a certain frequency even with laparoscopic radical prostatectomy (LRP). According to the literature, about 14% of patients who undergo LRP develop a postoperative IH (3). With the spread of the screening by prostate-specific antigen (PSA), the number of patients diagnosed with organconfined prostate cancer and who subsequently undergo radical prostatectomy has increased drastically (6,7). In proportion to the cases of operation, the importance of the postoperative complications have been focused recently. Urinary incontinence and erectile dysfunction are major complications in both conventional RRP and LRP; however, IH has not been focused as a complication because there seemed not to be a definite relationship between the operative procedure and postoperative IH. Patients who develop IH certainly suffer from its complications, and often undergo a repair procedure. IH degrades the quality of life of the patient after the surgery. This study was undertaken to determine the relationship between LRP and postoperative IH and to investigate the risk factors of IH after LRP. PATIENTS AND METHODS We retrospectively reviewed a total of 514 patients with prostate cancer who underwent LRP at our institution from November 2000 to November 2007. A total of 9 patients were excluded from analysis due to a follow-up shorter than 3 months, and 10 patients who had preexisting IH before LRP without IH repair were also excluded from current study. The patients were questioned about past medical history, including undergoing operations. The patients were followed-up every 3 months after the operation, and were examined to confirm whether an IH had subsequently occurred. IH was defined as symptomatic inguinal bulging with or without discomfort of groin. Patient records were also reviewed according to preoperative parameters, including age, BMI, preoperative PSA level, prostate volume and preoperative risk factors, including a history of previous major abdominal surgery, previous appendectomy and previous IH repair. Postoperative urethral stricture was eliminated from analysis because only two patients were observed during follow-up period. Perioperative risk factors, including operating time and surgical procedure, were also reviewed. Transperitoneal approach (TPA) was performed from November 2000 to December 2002 according to the Montsouris technique (8) in 81 of the 493 patients, while the extraperitoneal approach (EPA) based on the reports of Bollens et al. (9) and Stolzenburg et al. (10) was performed from January 2003 to November 2007 in 412 patients. At our institution, LRP was performed by three operators who underwent the operation with same procedures and same follow-up protocols. There were no significant differences in preopetative risk factors and perioperative risk factors between those different operators (data was not shown). Table 1. Patient characteristics Characteristic TPA (n ¼ 81) EPA (n ¼ 412) Median follow-up time (months) 74.0 24.0* Age 65.2 + 5.1 64.6 + 6.0 PSA (ng/ml) 9.5 + 7.3 7.5 + 6.1* BMI (kg/m 2 ) 24.3 + 2.5 24.1 + 4.2 Prostate volume (ml) 38.5 + 11.9 36.4 + 16.7 Previous major abdominal surgery 4 24 Previous appendectomy 7 56 Previous inguinal hernia repair 1 16 Operative time (min) 380 + 115 211 + 73* Postoperative inguinal hernia No. 4 (4.9%) 37 (9.0%) TPA, transperitoneal approach; EPA, extraperitoneal approach; PSA, prostate-specific antigen; BMI, body mass index. *P, 0.05. The IH-free rate was estimated using Kaplan Meier analysis, and the differences among groups were tested using the log-rank test. Cox proportional hazard analysis was used to determine the predictors of IH. RESULTS A total of 493 patients were followed by median 29.0 months after the operation. Using the Kaplan Meier method, 1-year and 2-year IH-free rates were calculated 94.0 and 92.0%, respectively. The patient characteristics which were divided in two groups according to operative procedure are listed on Table 1. There were significant differences in the preoperative PSA level, follow-up time and operative time between the TPA and EPA groups. The follow-up time was longer in the TPA group than in the EPA group. During follow-up, IH occurred in 4 (4.9%) of 81 patients in the TPA group, and in 37 (9.0%) of 412 patients in the EPA group. The total incidence of IH was 8.3% (41 of 493 patients). The median interval of IH-free survival was 35 months and 6 months in the TPA and EPA groups, respectively. The characteristics in patients in whom an IH developed are listed on Table 2. The incidence of IH within 2 years of the operation was 50% (2 of 4 patients) in the TPA group, 91.9% (34 of 37 patients) in the EPA group, and 87.8% (36 of 41 patients) overall. In the EPA group, IH had developed in 22 (59.5%) of 37 patients within 6 months, and in 27 (73.0%) of 37 patients within 12 months of the surgery. IH developed postoperatively in only two patients who had a history of IH repair. Table 2 shows that there was a significant difference in median interval of IH-free survival between the TPA and EPA groups. IH occurred significantly earlier in the EPA group than in the TPA group, and the laterality was rightside dominant in both groups; 65.8% were right side, 24.4%
Jpn J Clin Oncol 2009 Page 3 of 5 Table 2. Characteristics of patients in whom inguinal hernia developed Table 3. Univariate and multivariate analysis of inguinal hernia Characteristic TPA (n ¼ 4) EPA (n ¼ 37) Age 62.8 + 4.8 65.7 + 4.9 PSA (ng/ml) 12.4 + 7.0 6.1 + 4.5* BMI (kg/m 2 ) 22.5 + 2.7 23.0 + 2.9 Operative time (min) 447 + 257 209 + 72* Median interval of inguinal hernia free survival (months) 35.0 6.0* Hernia side Right 3 24 Left 1 9 Bilateral 0 4 *P, 0.05. Figure 1. Kaplan Meier analysis comparing hernia-free rate in transperitoneal approach group and in extraperitoneal approach group. were left side, and 9.8% were bilateral. Figure 1 shows the IH-free survival rate for the TPA and EPA groups. The incidence of IH was significantly higher in the EPA group compared with the TPA group. Univariate and multivariate analysis revealed that EPA was a significant risk factor for IH (P ¼ 0.043), while the other factors were not significant (Table 3). DISCUSSION Since Guillonneau and Vallancien (8) first described their technique for LRP, the number of patients treated laparoscopically has been steadily increasing as a minimally invasive surgery for localized prostate cancer, because of the lower estimated blood loss, decreased surgical pain and shorter duration of catheterization. Bollens et al. (9) subsequently reported a pure EPA for prostate cancer, which is more comparable to the open technique and avoids the potential risk of Patients (n) Univariate Multivariate P-value Hazard ratio (95% CI) P-value Age 65 268 0.703 65, 225 PSA (ng/ml) 8 178 0.627 8, 315 BMI (kg/m 2 ) 24 252 0.300 24, 241 Prostate volume (ml) 35 229 0.264 35, 264 Previous major abdominal surgery Yes 31 0.690 No 462 Previous appendectomy Yes 66 0.811 No 427 Previous inguinal hernia repair Yes 17 0.583 No 476 Operative time (min) 240 169 0.496 240, 324 Operation EPA 412 0.036 3.126 (1.037 9.420) 0.043 TPA 81 CI, confidence interval. specific complications encountered with the TPA. Bollens et al. (9) also reported that the oncologic outcome, potency and continence appeared to be equivalent to open RRP or transperitoneal LRP. The technique for LRP has been continuously refined, and the number of patients who undergo LRP for organ-confined prostate cancer seems to have been increasing. To the best of our knowledge, there is only one published report that compared the incidence and risk factors of post-lrp IH (3); however, the influence of the operative procedure had not been fully discussed. We then sought to determine the incidence and risk factors according to the surgical approach. In the present study, we compared several parameters that were considered to affect IHs. Multivariate analysis showed that only EPA was a significant risk factor for IH, whereas
Page 4 of 5 Lap-prostatectomy and inguinal hernia age, PSA, BMI, prostate volume, previous abdominal surgery, previous appendectomy, previous IH repair and operative time were not significant risk factors for postoperative IH. The results of these studies suggest that EPA causes post-lrp IH more often than TPA. Differences in the operative procedure may predict the reason for the post operative IH. We believe that the critical difference between TPA and EPA is the dilation of extraperitoneal space using a balloon dissector which placed just below the umbilicus. In the case of TPA, the insufflation of carbon dioxide gas produces sufficient abdominal space to insert the manipulating ports and perform the prostatectomy, since TPA can create a wider space than EPA. However, EPA needs a space in the Retzius cavity. In this procedure, the back wall of the internal inguinal ring may be weakened and the fragility of the internal inguinal ring may cause a successive IH later on. An IH was noticed significantly earlier in the EPA group than in the TPA group. This may suggest that the influence of surgical manipulation has relevance to EPA group with respect to the development of an IH than in TPA. Another interesting observation was the difference in the laterality of the IH that occurred. We determined the laterality of the IHs that developed. A right-side IH was detected significantly more often than a left side hernia. Abe et al. (3) reported the right-side dominance of post operative IH in a RRP group. They explained this by suggesting that a surgeon who stands on the left side of the patient may perform excessive dissection in the right groin area. On the other hand, Sekita et al. (11) reported that subclinical IH was found in 25% of RRP cases and the existence of subclinical IH was mainly right-sided (75%). This could reflect the right-side dominance of postoperative IH. However, there is no clear and definitive reason for explaining the right-side IH dominance. Further clinical investigations were needed to determine why the IH developed it in right side more often than left side. We demonstrated that extraperitoneal LRP caused a higher incidence of postoperative IH. However, our study may have some limitations. The operating time was different between the TPA and EPA groups, which may promote fragility of the inguinal canal induced by the high pressure of the carbon dioxide gas. Since any surgical technique has its own learning curve, EPA, which was started after TPA, should have some advantages with respect to TPA, resulting in a shorter operating time for EPA compared with TPA. In other words, even though the EPA technique was performed by an experienced operator and with a shorter operative time, it nonetheless still resulted in a greater incidence of IH than TPA. This result suggests that EPA definitely has an effect on the development of an IH compared with TPA. There was the disparity in the number of cases between TPA and EPA groups; however, EPA has potential advantage in the procedure compared with TPA concerning about the complications; no contact with bowel, imperviableness of previous abdominal surgery, less problem with extravasations (12). On the other hand, the incidence of IH in the general male population is approximately 5% (13). Coincidental IHs atsurgeryhavebeenreportedinupto33%ofpatientswith prostatectomy (14), and an incidental IH rate of 13% was also reported in patients undergoing laparoscopic surgery (15). Based on these reports, the possibility that subclinical IHs are overlooked needs to be considered, in other word, IH had predated LRP and come to light in the postoperative phase as these patients become symptomatic, even though a thorough physical examination is performed around the time of the operation. However, we could consider that the IH occurred newly clinically in which asymptomatic subclinical IH became to have presented a symptom postoperatively. The results of analysis showed that the complication was observed within 2 years postoperatively in 87.8% of the patients who had developed IH. For the urologist who follows post-lrp patients, a postoperative physical examination will become more important, because IHs sometimes cause not only pain and discomfort, but also a critical ileus. Moreover, patients who will undergo LRP should be informed of the risk of a postoperative IH, especially when the EPA technique is used. CONCLUSIONS IH is a frequent complication after LRP, and IHs develop more often by the EPA than by the TPA. Conflict of interest statement None declared. References 1. Lodding P, Bergdahl C, Nyberg M, Pileblad E, Stranne J, Hugosson J. Inguinal hernia after radical retropubic prostatectomy for prostate cancer: a study of incidence and risk factors in comparison to no operation and lymphadenectomy. JUrol2001;166:964 7. 2. Regan TC, Mordkin RM, Constantinople NL, Spence IJ, Dejter SW, Jr. Incidence of inguinal hernias following radical retropubic prostatectomy. Urology 1996;47:536 7. 3. Abe T, Shinohara N, Harabayashi T, Sazawa A, Suzuki S, Kawarada Y, et al. Postoperative inguinal hernia after radical prostatectomy for prostate cancer. Urology 2007;69:326 9. 4. Ichioka K, Kohei N, Yoshimura K, Arai Y, Terai A. Impact of retraction of vas deferens in postradical prostatectomy inguinal hernia. Urology 2007;70:511 4. 5. Twu CM, Ou YC, Yang CR, Cheng CL, Ho HC. Predicting risk factors for inguinal hernia after radical retropubic prostatectomy. Urology 2005;66:814 8. 6. Cooperberg MR, Broering JM, Litwin MS, Lubeck DP, Mehta SS, Henning JM, et al. The contemporary management of prostate cancer in the United States: lessons from the cancer of the prostate strategic urologic research endeavor (CapSURE), a national disease registry. JUrol2004;171:1393 401. 7. Partin AW, Mangold LA, Lamm DM, Walsh PC, Epstein JI, Pearson JD. Contemporary update of prostate cancer staging nomograms (Partin Tables) for the new millennium. Urology 2001;58:843 8. 8. Guillonneau B, Vallancien G. Laparoscopic radical prostatectomy: the Montsouris technique. JUrol2000;163:1643 9.
Jpn J Clin Oncol 2009 Page 5 of 5 9. Bollens R, Vanden Bossche M, Roumeguere T, Damoun A, Ekane S, Hoffmann P, et al. Extraperitoneal laparoscopic radical prostatectomy. Results after 50 cases. Eur Urol 2001;40:65 9. 10. Stolzenburg JU, Do M, RabenaltR,PfeifferH,HornL,TrussMC, et al. Endoscopic extraperitoneal radical prostatectomy: initial experience after 70 procedures. JUrol2003;169:2066 71. 11. Sekita N, Suzuki H, Kamijima S, Chin K, Fujimura M, Mikami K, et al. Incidence of inguinal hernia after prostate surgery: open radical retropubic prostatectomy versus open simple prostatectomy versus transurethral resection of the prostate. Int J Urol 2009;16:110 3. 12. Erdogru T, Teber D, Frede T, Marrero R, Hammady A, Seemann O, et al. Comparison of transperitoneal and extraperitoneal laparoscopic radical prostatectomy using match-pair analysis. Eur Urol 2004;46:312 9; discussion 20. 13. Finley DS, Rodriguez E, Jr, Ahlering TE. Combined inguinal hernia repair with prosthetic mesh during transperitoneal robot assisted laparoscopic radical prostatectomy: a 4-year experience. J Urol 2007;178:1296 9; discussion 9-300. 14. Nielsen ME, Walsh PC. Systematic detection and repair of subclinical inguinal hernias at radical retropubic prostatectomy. Urology 2005;66:1034 7. 15. Watson DS, Sharp KW, Vasquez JM, Richards WO. Incidence of inguinal hernias diagnosed during laparoscopy. South Med J 1994; 87:23 5.