Mesh Repair of Inguinal Hernias — Redux
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《新英格兰医药杂志》
An abdominal-wall hernia occurs when the abdominal contents protrude through a congenital or acquired defect in the supportive tissues. Although hernias can develop in many locations, including areas weakened by surgical incisions, they are most commonly identified in the groin or around the umbilicus. More than 800,000 hernia operations were performed in the United States in 2003; most of them were performed in men and on an outpatient basis, and most involved the use of mesh prostheses.1
Until the late 1980s, the standard method of inguinal hernia repair was the suturing of various fascial structures bordering the hernia defect. These repairs could create substantial tension at the suture lines, a complication that was known to impair healing. Lichtenstein and others advanced the concept of a tension-free approach that could be performed with the use of local anesthesia2 (Figure 1). Validation of the concept that excessive suture-line tension could lead to postoperative pain and an increased risk of recurrence of the hernia was largely responsible for the rapid and widespread adoption of tension-free herniorrhaphy as the repair method of choice. Just as tension-free repair was becoming the norm, minimally invasive laparoscopic approaches to the repair of inguinal hernias were introduced.3 These techniques required general anesthesia, but in most instances they allowed the use of smaller incisions and permitted faster recovery. Repairs were accomplished transabdominally by buttressing the hernia defect and the inguinal region with large mesh prostheses.
Figure 1. Illustration of a Mesh-Overlay Repair of Direct Inguinal Hernia.
The upper part of the figure shows the hernia bulging through the floor of the inguinal canal. The bottom part of the figure shows a mesh patch that has been laid over the inguinal floor and secured around the spermatic cord.
The identification of the best approach for the repair of inguinal hernias has been elusive and highly controversial. Two recent meta-analyses illustrate the uncertainty. Memon and colleagues4 reviewed the data from 29 published randomized, clinical trials and concluded that patients who underwent laparoscopic repair of an inguinal hernia were discharged earlier and able to return to their usual activities more quickly than patients who underwent open repair, although the laparoscopic operation took longer. Their analysis also suggested that patients who underwent laparoscopic repair had fewer postoperative complications. In an analysis of 41 studies comparing laparoscopic and open repair, McCormack et al.5 also found that laparoscopic herniorrhaphy required longer operative times than the open-repair procedure and that patients who underwent the laparoscopic procedure appeared to have less discomfort and to return to their usual activities more rapidly; recurrence rates were similar with the two approaches. Although operative complications were infrequent, visceral and vascular injuries appeared to occur more often among the patients who underwent laparoscopy. The discrepant results of the two meta-analyses may be explained by their different selection criteria for study inclusion. Memon et al. limited their search of the literature to English-language citations, whereas McCormack et al. reviewed published and unpublished, randomized and quasi-randomized, trials in any language.
Concern about operative complications with laparoscopic repair had been expressed earlier, in 1999, when the results of a randomized trial conducted by the Medical Research Council Laparoscopic Hernia Group were published.6 In this trial, all serious complications and recurrences occurred in the laparoscopic group. No association was found between surgeons' experience and the rate of complications. Some suggested that the results supported the development of specialized hernia centers. Others believed that the findings argued against specialized training in laparoscopic hernia repair, since nonspecialists performing open herniorrhaphy could achieve excellent results.
In this issue of the Journal, Neumayer and colleagues report the results of a large, carefully designed, prospective, randomized trial in which they compared open mesh repair and laparoscopic mesh repair of inguinal hernias at 14 Veterans Affairs medical centers.7 Their key findings address some of the current controversies but also raise additional questions. Patients in the laparoscopic-repair group had a higher rate of recurrence than those in the open-repair group (10.1 percent vs. 4.9 percent). Although patients in the laparoscopic-repair group reported less pain over the short term and resumed their normal activities somewhat earlier than those in the open-repair group, their rates of intraoperative, postoperative, and life-threatening complications were higher.
Neumayer et al. also performed a post hoc evaluation of the association between surgeons' self-reported experience and the rate of hernia recurrence. Their data suggest the presence of a steep learning curve for the laparoscopic method, but not for the open method, of hernia repair. The recurrence rate among patients whose surgeons stated that they had performed more than 250 laparoscopic operations was approximately half that among patients whose surgeons indicated that they had performed 250 or fewer such procedures. Recurrence rates after procedures performed by these highly experienced surgeons were similar for laparoscopic repair and open repair.
Several findings reported by Neumayer and colleagues are different from the results of a study reported by Liem et al. in the Journal seven years ago.8 The latter was also a randomized, multicenter trial comparing the laparoscopic and open approaches to inguinal hernia repair, but it was performed at selected teaching and nonteaching hospitals in rural and urban regions in the Netherlands. Mesh was used in all the laparoscopic procedures but was used in the open procedures only if an "adequate" repair could not otherwise be accomplished (3 percent of the open-repair cases). Patients with inguinal hernias that were repaired laparoscopically recovered more rapidly and had a lower rate of recurrence than those in the open-repair group (3 percent vs. 6 percent). Precise data pertaining to surgeons' experience and training were not reported.
What might account for the differences between the findings of the two studies? For one, the patients in the trial by Neumayer et al. appear to have been sicker than those in the study by Liem et al.: the majority of the patients studied by Neumayer et al. were in American Society of Anesthesiologists class II or higher, roughly 40 percent were smokers, approximately 9 percent had a chronic cough, and approximately 35 percent had hypertension. Second, most of the patients in the open-repair group in the study by Liem et al. did not undergo tension-free repair, which is currently considered the standard of care. Other differences between the studies include the type of anesthesia used (all the patients in the study by Liem et al. received general anesthesia), the nature of the study sites (including their geographic location), the sex distribution of the participants (all the participants in the study by Neumayer et al. were men), the intensity of monitoring, and perhaps the prior training of the resident and attending surgeons.
Nevertheless, the findings reported by Neumayer et al. indicate that most general surgeons can achieve excellent outcomes in hernia repair by using the tension-free open technique with local anesthesia — a procedure that is less complicated and probably safer than the tension-free laparoscopic technique with local anesthesia. They also remind us that substantive short-term and long-term complications may occur, even after "simple" hernia surgery.
Why did the surgeons in this study, who were presumably quite experienced in the performance of laparoscopic cholecystectomy (an operation that was introduced and adopted much earlier than laparoscopic herniorrhaphy and that is technically less demanding), need to perform so many laparoscopic herniorrhaphies to achieve the lowest recurrence rates? The answer is unclear. The results of one study suggest that a community-based general surgeon who is experienced in laparoscopic cholecystectomy and open hernia repair needs to perform only 50 laparoscopic hernia-repair procedures to achieve sufficient mastery in the technique.9
The relationship between the volume of procedures performed and the outcomes is not straightforward. It is apparent that some low-volume hospitals have good outcomes and some high-volume institutions have relatively poor outcomes.10 More important for patients and educators is the observation that some surgeons who perform small numbers of certain procedures appear to have excellent outcomes wherever they operate. What is it about these surgeons or their training that facilitates such competency? Is it the total number of a particular type of operation that a surgeon has performed over the course of his or her career or within a certain time frame? Exactly when and how does a surgeon who is competent but performs fewer procedures with less favorable outcomes become a surgeon who has favorable outcomes, whether the number of procedures performed is low or high? Can one facilitate this transition by means of computer-based, high-fidelity patient simulation? Given that many surgical trainees finish their residency having participated in fewer than 100 hernia operations, and given that most herniorrhaphies performed in this country are not performed by surgeons in specialized centers but, rather, by surgeons who may undertake fewer than 100 hernia repairs per year, we need to answer these questions next.
Source Information
From Duke University Medical Center, Durham, N.C.
References
Rutkow IM. Demographic and socioeconomic aspects of hernia repair in the United States in 2003. Surg Clin North Am 2003;83:1045-1051.
Lichtenstein IL, Shulman AG, Amid PK, Montllor MM. The tension-free hernioplasty. Am J Surg 1989;157:188-193.
Ger R. The management of certain abdominal herniae by intra-abdominal closure of the neck of the sac: preliminary communication. Ann R Coll Surg Engl 1982;64:342-344.
Memon MA, Cooper NJ, Memon B, Memon MI, Abrams KR. Meta-analysis of randomized clinical trials comparing open and laparoscopic inguinal hernia repair. Br J Surg 2003;90:1479-1492.
McCormack K, Scott NW, Go PM, Ross S, Grant AM. Laparoscopic techniques versus open techniques for inguinal hernia repair. Cochrane Database Syst Rev 2003;1:CD001785-CD001785.
Bower H. Laparoscopic hernia surgery linked to increased complications. BMJ 1999;319:211A-211A.
Neumayer L, Giobbie-Hurder A, Jonasson O, et al. Open mesh versus laparoscopic mesh repair of inguinal hernia. N Engl J Med 2004;350:1819-1827.
Liem MSL, van der Graaf Y, van Steensel CJ, et al. Comparison of conventional anterior surgery and laparoscopic surgery for inguinal-hernia repair. N Engl J Med 1997;336:1541-1547.
Voitk AJ. The learning curve in laparoscopic inguinal hernia for the community general surgeon. Can J Surg 1998;41:446-450.
Kizer KW. The volume-outcome conundrum. N Engl J Med 2003;349:2159-2161.(Danny O. Jacobs, M.D., M.)
Until the late 1980s, the standard method of inguinal hernia repair was the suturing of various fascial structures bordering the hernia defect. These repairs could create substantial tension at the suture lines, a complication that was known to impair healing. Lichtenstein and others advanced the concept of a tension-free approach that could be performed with the use of local anesthesia2 (Figure 1). Validation of the concept that excessive suture-line tension could lead to postoperative pain and an increased risk of recurrence of the hernia was largely responsible for the rapid and widespread adoption of tension-free herniorrhaphy as the repair method of choice. Just as tension-free repair was becoming the norm, minimally invasive laparoscopic approaches to the repair of inguinal hernias were introduced.3 These techniques required general anesthesia, but in most instances they allowed the use of smaller incisions and permitted faster recovery. Repairs were accomplished transabdominally by buttressing the hernia defect and the inguinal region with large mesh prostheses.
Figure 1. Illustration of a Mesh-Overlay Repair of Direct Inguinal Hernia.
The upper part of the figure shows the hernia bulging through the floor of the inguinal canal. The bottom part of the figure shows a mesh patch that has been laid over the inguinal floor and secured around the spermatic cord.
The identification of the best approach for the repair of inguinal hernias has been elusive and highly controversial. Two recent meta-analyses illustrate the uncertainty. Memon and colleagues4 reviewed the data from 29 published randomized, clinical trials and concluded that patients who underwent laparoscopic repair of an inguinal hernia were discharged earlier and able to return to their usual activities more quickly than patients who underwent open repair, although the laparoscopic operation took longer. Their analysis also suggested that patients who underwent laparoscopic repair had fewer postoperative complications. In an analysis of 41 studies comparing laparoscopic and open repair, McCormack et al.5 also found that laparoscopic herniorrhaphy required longer operative times than the open-repair procedure and that patients who underwent the laparoscopic procedure appeared to have less discomfort and to return to their usual activities more rapidly; recurrence rates were similar with the two approaches. Although operative complications were infrequent, visceral and vascular injuries appeared to occur more often among the patients who underwent laparoscopy. The discrepant results of the two meta-analyses may be explained by their different selection criteria for study inclusion. Memon et al. limited their search of the literature to English-language citations, whereas McCormack et al. reviewed published and unpublished, randomized and quasi-randomized, trials in any language.
Concern about operative complications with laparoscopic repair had been expressed earlier, in 1999, when the results of a randomized trial conducted by the Medical Research Council Laparoscopic Hernia Group were published.6 In this trial, all serious complications and recurrences occurred in the laparoscopic group. No association was found between surgeons' experience and the rate of complications. Some suggested that the results supported the development of specialized hernia centers. Others believed that the findings argued against specialized training in laparoscopic hernia repair, since nonspecialists performing open herniorrhaphy could achieve excellent results.
In this issue of the Journal, Neumayer and colleagues report the results of a large, carefully designed, prospective, randomized trial in which they compared open mesh repair and laparoscopic mesh repair of inguinal hernias at 14 Veterans Affairs medical centers.7 Their key findings address some of the current controversies but also raise additional questions. Patients in the laparoscopic-repair group had a higher rate of recurrence than those in the open-repair group (10.1 percent vs. 4.9 percent). Although patients in the laparoscopic-repair group reported less pain over the short term and resumed their normal activities somewhat earlier than those in the open-repair group, their rates of intraoperative, postoperative, and life-threatening complications were higher.
Neumayer et al. also performed a post hoc evaluation of the association between surgeons' self-reported experience and the rate of hernia recurrence. Their data suggest the presence of a steep learning curve for the laparoscopic method, but not for the open method, of hernia repair. The recurrence rate among patients whose surgeons stated that they had performed more than 250 laparoscopic operations was approximately half that among patients whose surgeons indicated that they had performed 250 or fewer such procedures. Recurrence rates after procedures performed by these highly experienced surgeons were similar for laparoscopic repair and open repair.
Several findings reported by Neumayer and colleagues are different from the results of a study reported by Liem et al. in the Journal seven years ago.8 The latter was also a randomized, multicenter trial comparing the laparoscopic and open approaches to inguinal hernia repair, but it was performed at selected teaching and nonteaching hospitals in rural and urban regions in the Netherlands. Mesh was used in all the laparoscopic procedures but was used in the open procedures only if an "adequate" repair could not otherwise be accomplished (3 percent of the open-repair cases). Patients with inguinal hernias that were repaired laparoscopically recovered more rapidly and had a lower rate of recurrence than those in the open-repair group (3 percent vs. 6 percent). Precise data pertaining to surgeons' experience and training were not reported.
What might account for the differences between the findings of the two studies? For one, the patients in the trial by Neumayer et al. appear to have been sicker than those in the study by Liem et al.: the majority of the patients studied by Neumayer et al. were in American Society of Anesthesiologists class II or higher, roughly 40 percent were smokers, approximately 9 percent had a chronic cough, and approximately 35 percent had hypertension. Second, most of the patients in the open-repair group in the study by Liem et al. did not undergo tension-free repair, which is currently considered the standard of care. Other differences between the studies include the type of anesthesia used (all the patients in the study by Liem et al. received general anesthesia), the nature of the study sites (including their geographic location), the sex distribution of the participants (all the participants in the study by Neumayer et al. were men), the intensity of monitoring, and perhaps the prior training of the resident and attending surgeons.
Nevertheless, the findings reported by Neumayer et al. indicate that most general surgeons can achieve excellent outcomes in hernia repair by using the tension-free open technique with local anesthesia — a procedure that is less complicated and probably safer than the tension-free laparoscopic technique with local anesthesia. They also remind us that substantive short-term and long-term complications may occur, even after "simple" hernia surgery.
Why did the surgeons in this study, who were presumably quite experienced in the performance of laparoscopic cholecystectomy (an operation that was introduced and adopted much earlier than laparoscopic herniorrhaphy and that is technically less demanding), need to perform so many laparoscopic herniorrhaphies to achieve the lowest recurrence rates? The answer is unclear. The results of one study suggest that a community-based general surgeon who is experienced in laparoscopic cholecystectomy and open hernia repair needs to perform only 50 laparoscopic hernia-repair procedures to achieve sufficient mastery in the technique.9
The relationship between the volume of procedures performed and the outcomes is not straightforward. It is apparent that some low-volume hospitals have good outcomes and some high-volume institutions have relatively poor outcomes.10 More important for patients and educators is the observation that some surgeons who perform small numbers of certain procedures appear to have excellent outcomes wherever they operate. What is it about these surgeons or their training that facilitates such competency? Is it the total number of a particular type of operation that a surgeon has performed over the course of his or her career or within a certain time frame? Exactly when and how does a surgeon who is competent but performs fewer procedures with less favorable outcomes become a surgeon who has favorable outcomes, whether the number of procedures performed is low or high? Can one facilitate this transition by means of computer-based, high-fidelity patient simulation? Given that many surgical trainees finish their residency having participated in fewer than 100 hernia operations, and given that most herniorrhaphies performed in this country are not performed by surgeons in specialized centers but, rather, by surgeons who may undertake fewer than 100 hernia repairs per year, we need to answer these questions next.
Source Information
From Duke University Medical Center, Durham, N.C.
References
Rutkow IM. Demographic and socioeconomic aspects of hernia repair in the United States in 2003. Surg Clin North Am 2003;83:1045-1051.
Lichtenstein IL, Shulman AG, Amid PK, Montllor MM. The tension-free hernioplasty. Am J Surg 1989;157:188-193.
Ger R. The management of certain abdominal herniae by intra-abdominal closure of the neck of the sac: preliminary communication. Ann R Coll Surg Engl 1982;64:342-344.
Memon MA, Cooper NJ, Memon B, Memon MI, Abrams KR. Meta-analysis of randomized clinical trials comparing open and laparoscopic inguinal hernia repair. Br J Surg 2003;90:1479-1492.
McCormack K, Scott NW, Go PM, Ross S, Grant AM. Laparoscopic techniques versus open techniques for inguinal hernia repair. Cochrane Database Syst Rev 2003;1:CD001785-CD001785.
Bower H. Laparoscopic hernia surgery linked to increased complications. BMJ 1999;319:211A-211A.
Neumayer L, Giobbie-Hurder A, Jonasson O, et al. Open mesh versus laparoscopic mesh repair of inguinal hernia. N Engl J Med 2004;350:1819-1827.
Liem MSL, van der Graaf Y, van Steensel CJ, et al. Comparison of conventional anterior surgery and laparoscopic surgery for inguinal-hernia repair. N Engl J Med 1997;336:1541-1547.
Voitk AJ. The learning curve in laparoscopic inguinal hernia for the community general surgeon. Can J Surg 1998;41:446-450.
Kizer KW. The volume-outcome conundrum. N Engl J Med 2003;349:2159-2161.(Danny O. Jacobs, M.D., M.)