Hernia DOI 10.1007/s10029-014-1323-8
ORIGINAL ARTICLE
Prophylactic procedure for inguinal hernia after radical retropubic prostatectomy R. Matsunaga • M. Negishi • H. Higashi H. Shida • K. Akakura
•
Received: 26 January 2014 / Accepted: 26 October 2014 Ó Springer-Verlag France 2014
Abstract Purpose The incidence of inguinal hernias (IH) after radical retropubic prostatectomy (RRP) has been reported to range from 10 to 50 %, but no prophylaxis for IH has yet been established. We proposed a prophylaxis for IH after RRP. Methods A total of 180 patients underwent RRP at our hospital between 2000 and 2011. In January 2008, we started to perform a prophylaxis involving the dissection of the processus vaginalis. This procedure was performed in 73 patients. We then compared the incidence of IH between the patients that did (prophylaxis group) and did not (no prophylaxis group) undergo the prophylaxis. We also studied the risk factors for IH after RRP. Results In the no prophylaxis group, 25 (23 %) of the 107 patients developed IH, and the IH-free rate at one postoperative year was 86 %. In contrast, only 3 (4.1 %) of the 73 patients in the prophylaxis group developed IH, resulting in IH-free rate of 96 % at one postoperative year (P = 0.0235). Among the patients in the no prophylaxis group, the mean body mass index of the hernia group was significantly lower than that of the no hernia group (P = 0.006). Conclusion Our results suggest that our prophylaxis is useful for preventing IH after RRP.
Introduction During the last decade, the number of patients undergoing radical retropubic prostatectomy (RRP) has risen markedly because of the increasing use of prostate-specific antigen testing [1]. Urinary incontinence and erectile dysfunction are the two major postoperative complications of RRP [2]. However, the high incidence of inguinal hernias (IH) after RRP has recently become a concern [3]. Namely, the incidence of IH after RRP has been reported to range from 10 to 50 % [4–11], while the overall prevalence of IH in the general male population is approximately 4–5 % [12, 13]. The etiology of IH after RRP remains unknown. Indirect hernias are much more common than direct hernias after RRP [4, 7, 13]. Generally, most indirect IH are considered to arise because of incomplete obliteration of the fetal processus vaginalis. Therefore, we have begun to laterally detach the peritoneum and dissect the processus vaginalis during RRP as a prophylactic procedure against IH. The effect of this prophylactic procedure was examined by comparing the incidence of IH between patients that did (the prophylaxis group) and did not (the no prophylaxis group) undergo the procedure during RRP. We also studied the risk factors for IH after RRP.
Keywords Inguinal hernia Prophylaxis Prostatectomy Hernia-free rate Methods R. Matsunaga (&) M. Negishi H. Higashi H. Shida Department of Surgery, Tokyo Kosei Nenkin Hospital, Tokyo, Japan e-mail: [email protected] K. Akakura Department of Urology, Tokyo Kosei Nenkin Hospital, Tokyo, Japan
Patients A total of 180 patients underwent RRP for clinically localized prostate cancer at our hospital between January 2000 and December 2011. From January 2008 onwards, we also performed a prophylactic procedure aimed at
123
Hernia
preventing IH at the same time as RRP. This procedure was performed in 73 patients. The other 107 patients were treated without any IH prophylaxis, including 10 patients in which the operator decided not to perform the prophylaxis after we started it. All patients were followed-up at an outpatient clinic. Diagnosis of IH We define an inguinal hernia as bulge from inguinal region which can be put back into abdominal space through an inguinal ring. Before each patient underwent RRP, they were asked whether they were suffering from any symptoms of IH, and a physical examination was also carried out. If a patient was diagnosed with IH at this point, they were excluded from the study. The exclusion criteria were applied since 2000. In case of a small bulge detected during operation, we included it in our study and treated it according to prophylaxis procedure. The patients were asked the same questions and underwent the same examinations during each of their postoperative visits to the urologist who operated RRP, which meant that the evaluation was not blinded. When an IH was suspected, the patient was referred to general surgeons for closer examination. Prophylactic procedure After making a lower abdominal midline incision, we gained access to the preperitoneal space. The prophylactic procedure was performed after pelvic lymphadenectomy and consisted of the following three steps: (1) the peritoneum was laterally detached from the inner surface of the abdominal wall, (2) the spermatic cord was separated from the peritoneum, and (3) the residual processus vaginalis was ligated with absorbable suture and dissected. The procedure only took 5 min for each side. If we meet a case of bulge of floor without any symptom before operation, we do not have to do any treatment. If there is some symptom, we will treat it according to repair of direct hernia. But we did not meet such a case until now.
Results The characteristics of the 180 patients are listed in Table 1. All of them were males, and there was no difference in age or body mass index (BMI) between the two groups. Among the 107 patients in the no prophylaxis group, 25 (23 %) developed IH during the median follow-up period of 88 months, and only 3 (4.1 %) of the 73 patients in the prophylaxis group developed IH during the median followup period of 21 months. The incidence of IH in the prophylaxis group was significantly lower than that observed in the no prophylaxis group, which was analyzed by Chisquare test (P \ 0.01). The no prophylaxis group exhibited IH-free rates of 86, 82, and 80 % at 1, 2, and 3 postoperative years, respectively. Of the 25 patients that developed IH after RRP, 16 (64 %) developed IH on their right side, 6 (24 %) suffered IH on their left side, and 3 (12 %) developed bilateral IH. In contrast, the prophylaxis group displayed IH-free rates of 96, 94, and 94 % at 1, 2, and 3 postoperative years, respectively. Consequently, the incidence of IH in the prophylaxis group was significantly lower than that observed in the no prophylaxis group, which was analyzed by log-rank statistic (P = 0.0235, Fig. 1). Of the three patients in the prophylaxis group that developed IH, 2 (67 %) developed IH on their right side and 1 (33 %) developed an IH on their left side. Among the 73 patients that underwent the prophylactic procedure, a residual processus vaginalis was definitely observed in 43 (59 %) patients. Without the prophylactic procedure it was difficult to notice a small processus vaginalis. The prophylactic procedure was not associated with any significant complications. We studied the risk factors for IH development in the 107 patients in the no prophylaxis group. Among these patients, the mean BMI of the hernia group (22.2 kg/m2) was significantly lower than that of the no hernia group (24.0 kg/m2; P = 0.006), and there was no significant difference in age or operative time between the two groups (Table 2). We also studied the risk factors in the prophylaxis group. There was no significant difference in BMI, age or operative time between the two groups (Table 3).
Statistical analysis Table 1 Patients’ characteristics
Data are presented as mean values. The results obtained for the two groups were compared with the student’s t test or Chi-square test. Kaplan–Meier curves were used to estimate the IH-free rates of the two groups, and these rates were compared using the log-rank statistic. Differences were considered significant when the associated P \ 0.05. All descriptive statistical analyses were performed with Statview 5.0.
123
Age (years) 2
BMI (kg/m )
Prophylaxis (-), N = 107
Prophylaxis (?), N = 73
Significanta
66.8 (49–76)
65.6 (46–73)
No
24.0 (17.7–29.0)
24.0 (19.2–32.3)
No
Data are presented as mean (range) values BMI body mass index a
Evaluated with the Student’s t test
Hernia
Fig. 1 Inguinal hernia (IH)-free rates in the presence and absence of a prophylactic procedure for IH as evaluated using the Kaplan–Meier method
Table 2 Risk factors for inguinal hernias after radical retropubic prostatectomy (without prophylaxis) IH (?), N = 25
IH (-), N = 82
Significant (P value)a
Age (years)
66.1 (54–76)
66.7 (49–80)
No (0.683)
BMI (kg/m2)
22.2 (17.7–25.0)
24.0 (18.8–29.0)
Yes (0.006)
Operative time (min)
214 (139–290)
216(115–417)
No (0.861)
Data are presented as mean (range) values IH inguinal hernia, BMI body mass index a
Evaluated with the Student’s t test
Table 3 Risk factors for inguinal hernias after radical retropubic prostatectomy (with prophylaxis) IH (?), N = 3
IH (-), N = 70
Significant (P value)a
66.3 (63–71)
65.5 (46–75)
No (0.404)
BMI (kg/m )
22.9 (21.6–23.8)
24.2 (18.7–30.9)
No (0.216)
Operative time (min)
200 (185–219)
219(166–489)
No (0.291)
Age (years) 2
Data are presented as mean (range) values IH inguinal hernia, BMI body mass index a
Evaluated with the Student’s t test
Discussion IH are a long-term complication of RRP. Our prophylactic procedure, i.e., the detachment of the peritoneum and dissection of the processus vaginalis, was suggested to prevent the development of IH after RRP. We analyzed the IH-free rates of patients that did or did not undergo this procedure using the Kaplan–Meier method. As a result, it was
demonstrated that the incidence of IH in the prophylaxis group was significantly lower than that observed in the no prophylaxis group (P = 0.0235, Fig. 1). All of the IH encountered in this study were indirect hernias. Generally speaking, indirect hernias are strongly associated with the residual processus vaginalis. Of course, the mechanism responsible for IH after RRP is probably multifactorial; however, we considered that the residual processus vaginalis was the main cause of the IH observed in the present study because our prophylactic procedure, which involved the dissection of the processus vaginalis, was demonstrated to be effective. However, this method is unsuitable for preventing direct hernias. To prevent IH after RRP, Sakai et al. [10] suggested the blunt detachment of the peritoneum at the internal inguinal ring and the isolation of the spermatic cord from the surrounding peritoneum. In a study examining the utility of this method, they reported that the incidence of IH was significantly lower in the prophylaxis group (1.6 %) than in the no prophylaxis group (50 %; P \ 0.0001). In addition, Fujii et al. [11] suggested that the spermatic cord should be isolated from the abdominal wall and that the processus vaginalis should be dissected in order to prevent IH after RRP. After analyzing the outcomes of their patients, they reported that the incidence of IH in the prophylaxis group (1.4 %) was significantly lower than that in the no prophylaxis group (24 %; P \ 0.0001). Our method involved both of these procedures, i.e., the detachment of the peritoneum and the dissection of the processus vaginalis. It should be noted that Stranne et al. [14] reported that prophylactic suturing of the internal inguinal ring also significantly reduced the incidence of IH after RRP (P = 0.011). Previous studies that examined the risk factors for IH after RRP found that previous IH surgery, increased age, low BMI, incision length, subclinical IH, previous major abdominal surgery, the postoperative wound complications rate, and anastomotic stricture were potential risk factors for the condition [5, 15, 16]. After eliminating patients that had undergone previous IH surgery from this study, we studied age, operative time, and BMI as risk factors for IH in the no prophylaxis group. As a result, we found that the mean BMI of the hernia group (22.2 kg/m2) was significantly lower than that of the no hernia group (24.0 kg/m2; P = 0.006), which suggested that prophylaxis is especially important for patients with low BMI. No significant intergroup differences in age or the operative time were detected. There are several commonly used treatments for prostate cancer, including RRP, minimally invasive prostatectomy (MIRP), and radiation therapy (RT). Nilsson et al. [13] reported that 14 % of males treated with RRP, 10 % of males treated with MIRP, and 8 % of males treated with
123
Hernia
RT had to undergo IH repair within 6 postoperative years compared with 4 % of the controls. A slight difference in the incidence of IH was detected between RRP and MIRP. However, it was suggested that the lower mean age, fewer comorbidities, and higher frequency of low-risk tumors observed in the MIRP group were indicative of selection bias. In addition, the fact that the males treated with RT displayed an almost twofold higher incidence of IH than the controls suggests that enhanced surveillance for IH increases its reported incidence. Sekita et al. [17] reported the incidence of IH after RRP, after open prostatectomy for benign prostatic hyperplasia (OP) and after transurethral resection of the prostate (TURP). The incidence of IH was 24 % in the RRP group, 19 % in OP group, and 2 % in the TURP group, i.e., the RRP and the OP group procedures significantly increased the incidence of IH compared with the TURP group (vs. RRP: P \ 0.001; vs. OP: P \ 0.001), suggesting that a lower abdominal incision itself was associated with the development of IH after RRP.
Conclusion Our results suggest that our prophylaxis involving the dissection of the processus vaginalis is useful for preventing IH after RRP. Prophylaxis is especially important for patients with low BMI. Conflict of interest RM, MN, HH and HS declare no conflict of interest. KA declares conflict of interest not directly related to the submitted work, payment for lectures including service on speaker bureaus.
References 1. Kawakami S, Kihara K (2009) Surgical practice for urological tumors: nation-wide survey in Japan in 2005. Int J Urol 16:257–262 2. Walsh PC (2000) Radical prostatectomy for localized prostate cancer provides durable cancer control with excellent quality of life: a structured debate. J Urol 163:1802–1807 3. Regan TC, Mordlkin RM, Constantinople NL, Spence IJ, Dejter SW (1996) Incidence of inguinal hernias following radical retropubic prostatectomy. Urology 47:536–537
123
4. Abe T, Shinohara N, Harabayashi T, Sazawa A, Suzuki S, Kawarada Y, Nonomura K (2007) Postoperative inguinal hernia after radical prostatectomy for prostate cancer. Urology 69:326–329 5. Twu CM, Ou YC, Yang CR, Cheng CL, Ho HC (2005) Predicting risk factors for inguinal hernia after radical retropubic prostatectomy. Urology 66:814–818 6. Ichioka K, Yoshimura K, Utsunomiya N, Ueda N, Matsui Y, Terai A, Arai Y (2004) High incidence of inguinal hernia after radical retropubic prostatectomy. Urology 63:278–281 7. Lodding P, Bergdahl C, Nyberg M, Pileblad E, Stranne J, Hugosson J (2001) Inguinal hernia after radical retropubic prostatectomy for prostate cancer: a study of incidence and risk factors in comparison to no operation and lymphadenectomy. J Urol 166:964–967 8. Stranne J, Hugosson J, Lodding P (2006) Post-radical retropubic prostatectomy inguinal hernia: an analysis of risk factors with special reference to preoperative inguinal hernia morbidity and pelvic node dissection. J Urol 176:2072–2076 9. Rutkow IM (1998) Epidemiologic, economic, and sociologic aspects of hernia surgery in the United States in the 1990s. Surg Clin N Am 78:941–951 10. Sakai Y, Okuno T, Kijima T, Iwai A, Matsuoka Y, Kawakami S, Kihara K (2009) Simple prophylactic procedure of inguinal hernia after radical retropubic prostatectomy: isolation of the spermatic cord. Int J Urol 16:848–851 11. Fujii Y, Yamamoto S, Yonese J, Kawakami S, Okubo Y, Suyama T, Komai Y, Kijima T, Fukui I (2010) A novel technique to prevent postradical retropubic prostatectomy inguinal hernia: the processus vaginalis transaction method. Urology 75:713–717 12. Nielsen ME, Walsh PC (2005) Systematic detection and repair of subclinical inguinal hernias at radical retropubic prostatectomy. Urology 66:1034–1037 13. Nilsson H, Stranne J, Stattin PS, Nordin P (2013) Incidence of groin hernia repair after radical prostatectomy. A populationbased nationwide study. Ann Surg 00:1–5 14. Stranne J, Aus G, Berdahl S, Damber JE, Hugosson J, Khatami A, Lodding P (2010) Post-radical prostatectomy inguinal hernia: a simple surgical intervention can substantially reduce the incidence-results from a prospective randomized trial. J Urol 184:984–989 15. Stranne J, Lodding P (2011) Inguinal hernia after radical retropubic prostatectomy: risk factors and prevention. Nat Rev Urol 8:267–273 16. Zhu S, Zhang H, Xie L, Chen J, Niu Y (2013) Risk factors and prevention of inguinal hernia after radical prostatectomy: a systematic review and meta-analysis. J Urol 189:884–890 17. Sekita N, Suzuki H, Kamijima S, Chin K, Fujimura M, Mikami K, Ichikawa T (2009) Incidence of inguinal hernia after prostate surgery: open radical retropubic prostatectomy versus open simple prostatectomy versus transurethral resection of the prostate. Int J Urol 16:110–113
ORIGINAL ARTICLE
Prophylactic procedure for inguinal hernia after radical retropubic prostatectomy R. Matsunaga • M. Negishi • H. Higashi H. Shida • K. Akakura
•
Received: 26 January 2014 / Accepted: 26 October 2014 Ó Springer-Verlag France 2014
Abstract Purpose The incidence of inguinal hernias (IH) after radical retropubic prostatectomy (RRP) has been reported to range from 10 to 50 %, but no prophylaxis for IH has yet been established. We proposed a prophylaxis for IH after RRP. Methods A total of 180 patients underwent RRP at our hospital between 2000 and 2011. In January 2008, we started to perform a prophylaxis involving the dissection of the processus vaginalis. This procedure was performed in 73 patients. We then compared the incidence of IH between the patients that did (prophylaxis group) and did not (no prophylaxis group) undergo the prophylaxis. We also studied the risk factors for IH after RRP. Results In the no prophylaxis group, 25 (23 %) of the 107 patients developed IH, and the IH-free rate at one postoperative year was 86 %. In contrast, only 3 (4.1 %) of the 73 patients in the prophylaxis group developed IH, resulting in IH-free rate of 96 % at one postoperative year (P = 0.0235). Among the patients in the no prophylaxis group, the mean body mass index of the hernia group was significantly lower than that of the no hernia group (P = 0.006). Conclusion Our results suggest that our prophylaxis is useful for preventing IH after RRP.
Introduction During the last decade, the number of patients undergoing radical retropubic prostatectomy (RRP) has risen markedly because of the increasing use of prostate-specific antigen testing [1]. Urinary incontinence and erectile dysfunction are the two major postoperative complications of RRP [2]. However, the high incidence of inguinal hernias (IH) after RRP has recently become a concern [3]. Namely, the incidence of IH after RRP has been reported to range from 10 to 50 % [4–11], while the overall prevalence of IH in the general male population is approximately 4–5 % [12, 13]. The etiology of IH after RRP remains unknown. Indirect hernias are much more common than direct hernias after RRP [4, 7, 13]. Generally, most indirect IH are considered to arise because of incomplete obliteration of the fetal processus vaginalis. Therefore, we have begun to laterally detach the peritoneum and dissect the processus vaginalis during RRP as a prophylactic procedure against IH. The effect of this prophylactic procedure was examined by comparing the incidence of IH between patients that did (the prophylaxis group) and did not (the no prophylaxis group) undergo the procedure during RRP. We also studied the risk factors for IH after RRP.
Keywords Inguinal hernia Prophylaxis Prostatectomy Hernia-free rate Methods R. Matsunaga (&) M. Negishi H. Higashi H. Shida Department of Surgery, Tokyo Kosei Nenkin Hospital, Tokyo, Japan e-mail: [email protected] K. Akakura Department of Urology, Tokyo Kosei Nenkin Hospital, Tokyo, Japan
Patients A total of 180 patients underwent RRP for clinically localized prostate cancer at our hospital between January 2000 and December 2011. From January 2008 onwards, we also performed a prophylactic procedure aimed at
123
Hernia
preventing IH at the same time as RRP. This procedure was performed in 73 patients. The other 107 patients were treated without any IH prophylaxis, including 10 patients in which the operator decided not to perform the prophylaxis after we started it. All patients were followed-up at an outpatient clinic. Diagnosis of IH We define an inguinal hernia as bulge from inguinal region which can be put back into abdominal space through an inguinal ring. Before each patient underwent RRP, they were asked whether they were suffering from any symptoms of IH, and a physical examination was also carried out. If a patient was diagnosed with IH at this point, they were excluded from the study. The exclusion criteria were applied since 2000. In case of a small bulge detected during operation, we included it in our study and treated it according to prophylaxis procedure. The patients were asked the same questions and underwent the same examinations during each of their postoperative visits to the urologist who operated RRP, which meant that the evaluation was not blinded. When an IH was suspected, the patient was referred to general surgeons for closer examination. Prophylactic procedure After making a lower abdominal midline incision, we gained access to the preperitoneal space. The prophylactic procedure was performed after pelvic lymphadenectomy and consisted of the following three steps: (1) the peritoneum was laterally detached from the inner surface of the abdominal wall, (2) the spermatic cord was separated from the peritoneum, and (3) the residual processus vaginalis was ligated with absorbable suture and dissected. The procedure only took 5 min for each side. If we meet a case of bulge of floor without any symptom before operation, we do not have to do any treatment. If there is some symptom, we will treat it according to repair of direct hernia. But we did not meet such a case until now.
Results The characteristics of the 180 patients are listed in Table 1. All of them were males, and there was no difference in age or body mass index (BMI) between the two groups. Among the 107 patients in the no prophylaxis group, 25 (23 %) developed IH during the median follow-up period of 88 months, and only 3 (4.1 %) of the 73 patients in the prophylaxis group developed IH during the median followup period of 21 months. The incidence of IH in the prophylaxis group was significantly lower than that observed in the no prophylaxis group, which was analyzed by Chisquare test (P \ 0.01). The no prophylaxis group exhibited IH-free rates of 86, 82, and 80 % at 1, 2, and 3 postoperative years, respectively. Of the 25 patients that developed IH after RRP, 16 (64 %) developed IH on their right side, 6 (24 %) suffered IH on their left side, and 3 (12 %) developed bilateral IH. In contrast, the prophylaxis group displayed IH-free rates of 96, 94, and 94 % at 1, 2, and 3 postoperative years, respectively. Consequently, the incidence of IH in the prophylaxis group was significantly lower than that observed in the no prophylaxis group, which was analyzed by log-rank statistic (P = 0.0235, Fig. 1). Of the three patients in the prophylaxis group that developed IH, 2 (67 %) developed IH on their right side and 1 (33 %) developed an IH on their left side. Among the 73 patients that underwent the prophylactic procedure, a residual processus vaginalis was definitely observed in 43 (59 %) patients. Without the prophylactic procedure it was difficult to notice a small processus vaginalis. The prophylactic procedure was not associated with any significant complications. We studied the risk factors for IH development in the 107 patients in the no prophylaxis group. Among these patients, the mean BMI of the hernia group (22.2 kg/m2) was significantly lower than that of the no hernia group (24.0 kg/m2; P = 0.006), and there was no significant difference in age or operative time between the two groups (Table 2). We also studied the risk factors in the prophylaxis group. There was no significant difference in BMI, age or operative time between the two groups (Table 3).
Statistical analysis Table 1 Patients’ characteristics
Data are presented as mean values. The results obtained for the two groups were compared with the student’s t test or Chi-square test. Kaplan–Meier curves were used to estimate the IH-free rates of the two groups, and these rates were compared using the log-rank statistic. Differences were considered significant when the associated P \ 0.05. All descriptive statistical analyses were performed with Statview 5.0.
123
Age (years) 2
BMI (kg/m )
Prophylaxis (-), N = 107
Prophylaxis (?), N = 73
Significanta
66.8 (49–76)
65.6 (46–73)
No
24.0 (17.7–29.0)
24.0 (19.2–32.3)
No
Data are presented as mean (range) values BMI body mass index a
Evaluated with the Student’s t test
Hernia
Fig. 1 Inguinal hernia (IH)-free rates in the presence and absence of a prophylactic procedure for IH as evaluated using the Kaplan–Meier method
Table 2 Risk factors for inguinal hernias after radical retropubic prostatectomy (without prophylaxis) IH (?), N = 25
IH (-), N = 82
Significant (P value)a
Age (years)
66.1 (54–76)
66.7 (49–80)
No (0.683)
BMI (kg/m2)
22.2 (17.7–25.0)
24.0 (18.8–29.0)
Yes (0.006)
Operative time (min)
214 (139–290)
216(115–417)
No (0.861)
Data are presented as mean (range) values IH inguinal hernia, BMI body mass index a
Evaluated with the Student’s t test
Table 3 Risk factors for inguinal hernias after radical retropubic prostatectomy (with prophylaxis) IH (?), N = 3
IH (-), N = 70
Significant (P value)a
66.3 (63–71)
65.5 (46–75)
No (0.404)
BMI (kg/m )
22.9 (21.6–23.8)
24.2 (18.7–30.9)
No (0.216)
Operative time (min)
200 (185–219)
219(166–489)
No (0.291)
Age (years) 2
Data are presented as mean (range) values IH inguinal hernia, BMI body mass index a
Evaluated with the Student’s t test
Discussion IH are a long-term complication of RRP. Our prophylactic procedure, i.e., the detachment of the peritoneum and dissection of the processus vaginalis, was suggested to prevent the development of IH after RRP. We analyzed the IH-free rates of patients that did or did not undergo this procedure using the Kaplan–Meier method. As a result, it was
demonstrated that the incidence of IH in the prophylaxis group was significantly lower than that observed in the no prophylaxis group (P = 0.0235, Fig. 1). All of the IH encountered in this study were indirect hernias. Generally speaking, indirect hernias are strongly associated with the residual processus vaginalis. Of course, the mechanism responsible for IH after RRP is probably multifactorial; however, we considered that the residual processus vaginalis was the main cause of the IH observed in the present study because our prophylactic procedure, which involved the dissection of the processus vaginalis, was demonstrated to be effective. However, this method is unsuitable for preventing direct hernias. To prevent IH after RRP, Sakai et al. [10] suggested the blunt detachment of the peritoneum at the internal inguinal ring and the isolation of the spermatic cord from the surrounding peritoneum. In a study examining the utility of this method, they reported that the incidence of IH was significantly lower in the prophylaxis group (1.6 %) than in the no prophylaxis group (50 %; P \ 0.0001). In addition, Fujii et al. [11] suggested that the spermatic cord should be isolated from the abdominal wall and that the processus vaginalis should be dissected in order to prevent IH after RRP. After analyzing the outcomes of their patients, they reported that the incidence of IH in the prophylaxis group (1.4 %) was significantly lower than that in the no prophylaxis group (24 %; P \ 0.0001). Our method involved both of these procedures, i.e., the detachment of the peritoneum and the dissection of the processus vaginalis. It should be noted that Stranne et al. [14] reported that prophylactic suturing of the internal inguinal ring also significantly reduced the incidence of IH after RRP (P = 0.011). Previous studies that examined the risk factors for IH after RRP found that previous IH surgery, increased age, low BMI, incision length, subclinical IH, previous major abdominal surgery, the postoperative wound complications rate, and anastomotic stricture were potential risk factors for the condition [5, 15, 16]. After eliminating patients that had undergone previous IH surgery from this study, we studied age, operative time, and BMI as risk factors for IH in the no prophylaxis group. As a result, we found that the mean BMI of the hernia group (22.2 kg/m2) was significantly lower than that of the no hernia group (24.0 kg/m2; P = 0.006), which suggested that prophylaxis is especially important for patients with low BMI. No significant intergroup differences in age or the operative time were detected. There are several commonly used treatments for prostate cancer, including RRP, minimally invasive prostatectomy (MIRP), and radiation therapy (RT). Nilsson et al. [13] reported that 14 % of males treated with RRP, 10 % of males treated with MIRP, and 8 % of males treated with
123
Hernia
RT had to undergo IH repair within 6 postoperative years compared with 4 % of the controls. A slight difference in the incidence of IH was detected between RRP and MIRP. However, it was suggested that the lower mean age, fewer comorbidities, and higher frequency of low-risk tumors observed in the MIRP group were indicative of selection bias. In addition, the fact that the males treated with RT displayed an almost twofold higher incidence of IH than the controls suggests that enhanced surveillance for IH increases its reported incidence. Sekita et al. [17] reported the incidence of IH after RRP, after open prostatectomy for benign prostatic hyperplasia (OP) and after transurethral resection of the prostate (TURP). The incidence of IH was 24 % in the RRP group, 19 % in OP group, and 2 % in the TURP group, i.e., the RRP and the OP group procedures significantly increased the incidence of IH compared with the TURP group (vs. RRP: P \ 0.001; vs. OP: P \ 0.001), suggesting that a lower abdominal incision itself was associated with the development of IH after RRP.
Conclusion Our results suggest that our prophylaxis involving the dissection of the processus vaginalis is useful for preventing IH after RRP. Prophylaxis is especially important for patients with low BMI. Conflict of interest RM, MN, HH and HS declare no conflict of interest. KA declares conflict of interest not directly related to the submitted work, payment for lectures including service on speaker bureaus.
References 1. Kawakami S, Kihara K (2009) Surgical practice for urological tumors: nation-wide survey in Japan in 2005. Int J Urol 16:257–262 2. Walsh PC (2000) Radical prostatectomy for localized prostate cancer provides durable cancer control with excellent quality of life: a structured debate. J Urol 163:1802–1807 3. Regan TC, Mordlkin RM, Constantinople NL, Spence IJ, Dejter SW (1996) Incidence of inguinal hernias following radical retropubic prostatectomy. Urology 47:536–537
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