Mesh-based repair technique for patients with inguinal and/or femoral hernia is strongly recommended and particularly for the prevention of recurrence. The synthetic permanent mesh had been the convention but came with limitations.1
A meta-analysis of patients with inguinal hernia undergoing repair with fully absorbable mesh, permanent or biological mesh found that patients with an absorbable mesh seem to have less chronic pain compared with repair with permanent meshes without increased risk of recurrence.2 The recurrence rate for all hernias following repair with an absorbable mesh was 3% in the first year and 8% after 2 to 5 years. Data on recurrence rates in this meta-analysis were largely found to be collected as part of clinical examinations. Among controlled and noncontrolled trials, the recurrence rate with absorbable mesh was 5.6%; (median: 13-mo follow-up; range: 6 to 60 mo). Among research clinical trials only, the recurrence rate was 2% for absorbable versus 1.3% for permanent mesh (median: 18-mo follow-up; range: 12 to 36 mo). Of the recurrence among permanent mesh, 73% had a primary medial hernia.2
The GORE SYNECOR Intraperitoneal Biomaterial (hereafter, device; W. L. Gore & Associates Inc.) is a hybrid composite mesh made of a bioabsorbable 3-dimensional web comprised of poly (glycolide:trimethylene carbonate) copolymer (PGA:TMC), a permanent macroporous dense polytetrafluoroethylene monofilament knit, and a nonporous bioabsorbable PGA:TMC film. Six to 7 months after implant, the bioabsorbable components are absorbed and only the polytetrafluoroethylene monofilament knit remains. This device is intended for intraperitoneal (IP) placement using an underlay or intraperitoneal onlay technique. The use of nonabsorbable sutures to secure the device is recommended. When the device is placed adjacent to fascia, tissue ingrown on the 3-dimensional web scaffold surface is expected. Further, when the device is placed adjacent to viscera, there should be minimal tissue attachment on the nonporous IP barrier film.3 The long-term data on use of this device in inguinal hernia is limited. The aim of this retrospective review was to evaluate the performance and safety of this IP device for the repair of inguinal hernias after 1 year. In this case series, the implanting physician chose to implant the device in the preperitoneal plane with the nonporous film positioned adjacent to the peritoneum to promote peritoneum growth to protect the device from bowel adhesions which is in line with the device instructions for use.3
METHODS
Study Design
The overall multicenter, retrospective study included adult patients with ventral, incisional, parastomal, and inguinal hernias who were treated with the IP device between April 2016 and May 2019. Data were collected across 4 hospitals in the United States. A record search was conducted to identify cases of patients at least 18 years of age, who underwent hernia repair with the use of the IP device and were treated at least 365 days before site initiation. Any implantation <1 year before site initiation was excluded. Cases were further categorized by hernia type, wound class by the Centers for Disease Control and Prevention (CDC) Surgical Wound Classification, and comorbidities. A wound classification of >1 was excluded. This report details only patients with the inguinal hernia type. The hernia repair technique used was determined by the implanting physician.
Additional exclusion criteria included use in the repair of cardiovascular defects, device placement with the antiadhesion barrier adjacent to fascial or subcutaneous tissue, and inability to achieve sufficient device overlap of the hernia defect. Further, evidence of systemic infection, known wound-healing disorder, cirrhosis, current dialysis, immunosuppression, or surgical site infection (SSI) at the time of device placement were also exclusionary.
Demographics, medical history, physical examination, adverse event, and device use data were collected retrospectively from existing medical records of eligible patients enrolled in the study with an inguinal hernia. A patient-reported outcome (PRO) questionnaire regarding hernia recurrence was administered, and events of surgical or autopsy procedure explant of the device were captured by the site.4 At 1, 6, 12, 24, and 36 months postoperatively, the questionnaire was administered and adverse events and device use data were evaluated.
The study was conducted in accordance with the US Federal regulations and with institutional review board approval. This study and medical writing assistance was funded by W. L. Gore & Associates Inc.
Endpoints
Three primary endpoints and secondary endpoints were evaluated. Detailed study endpoint definitions are provided in Supplemental Online Resource 1 (Supplemental Digital Content 1, https://links.lww.com/SLE/A369).
The first objective was the procedural endpoint and defined as incidence through 30 days of SSI, surgical site occurrence (SSO), ileus, readmission, reoperation, and death. All procedural endpoints were captured as device-related or procedure-related with the exception of death which was captured for device-related events only. Severity was captured as serious or nonserious for the SSI, SSO, and ileus events, and as serious only for readmission, reoperation, and death.
The second objective was the device endpoint which was defined as serious device incidence of mesh erosion, infection, excision/removal, exposure, migration, shrinkage, device-related bowel obstruction and fistula, and hernia recurrence through 12 months. All device endpoints were captured for events that were device-related or serious in severity.
The third objective was PRO of the bulge, physical symptoms, and pain. The PRO used in this study was the Ventral Hernia Recurrence Inventory (VHRI). This PRO is an adapted patient questionnaire that contains 3 “yes/no” questions regarding symptoms commonly associated with hernia recurrence.5 The instrument was shown to be a valid tool in the assessment of inguinal hernias.6 The responses on the PRO were not considered adverse events.
The secondary endpoints included SSO, SSI, bowel perforation, unexplained or chronic pain, seroma, fistula, or adhesion formation. Only device-related and serious severity events were captured for bowel perforation, unexplained or chronic pain, seroma, fistula, or adhesion formation. Device-related, procedure-related, serious, and nonserious events of SSO and SSI were also captured.
Statistical Methods
The 95% 2-sided CI was calculated using the exact binomial test for each estimate for the procedural, device, and PRO endpoints and included the all-enrolled patient population. Continuous data were summarized using descriptive statistics. Missing data were not included.
RESULTS
Patient Disposition
A total of 157 patients were enrolled with 201 inguinal hernias; 44 patients had 2 inguinal repairs on the same day as the primary procedure and 4 patients had a ventral hernia repair. All but 1 patient was enrolled from 1 investigative site. Patients with inguinal hernia were a mean age of 67±13 years and had a mean body mass index of 28±5 kg/m2. The population was largely male (90.5%), White (87.9%), and all were non-Hispanic. At baseline, associated comorbidities included hypertension (45.2%), hypercholesterolemia (38.9%), and cancer (25.5%). Few patients were current smokers (11.5%). Previous abdominal aortic surgery was reported in 4 (2.6%) patients.
Most patients had indirect hernia type, none were incarcerated or strangulated. No patient had a stoma present. The median hernia size was 4.0 cm2. All patients were of the “clean” CDC wound classification. Nearly all patients had a laparoscopic repair (99.4%). A total of 158 devices were implanted; 1 device per hernia for all patients with the exception of 1 patient that required 2 devices, 1 for a concomitant ventral hernia repair. The 10×15 cm device was used for a majority of the repairs (120/158; 75.9%). The 15×20 cm device was used in 35/158 repairs (22.2%) and the 12×12 cm or 20×25 cm devices were used in the remaining 3 repairs. All device placements were preperitoneal with the barrier film placed adjacent to the peritoneum. Reoperation of a recurrent inguinal hernia involving a previously placed hernia mesh occurred in 16 patients (10.2%). In 99.5% of procedures, the device was secured with absorbable fixation and used for bridging. The mean follow-up was 31 months (range: 15 to 50 mo). Table 1 details the demographics, medical history, and hernia characteristics at baseline.
TABLE 1 -
Patient Demographics, Baseline Medical History, and Baseline Hernia Characteristics of Patients With Inguinal Hernia
|
n (%) |
| No. patients enrolled (N) |
157 |
| No. inguinal hernias (N) |
201 |
| Demographics (N=157) |
| Male |
142 (90.4) |
| Age [mean (±SD)] (y) |
67 (13) |
| Weight [mean (±SD)] (lbs) |
192 (38) |
| BMI (kg/m2) |
|
| Mean (±SD) |
28 (5) |
| Range |
19-46 |
| Medical history (N=157) |
| Tobacco use, n (%) |
|
| Current |
18 (11.5) |
| Former |
69 (44.0) |
| Never |
70 (44.6) |
| Hypercholesterolemia |
61 (38.9) |
| Hypertension |
71 (45.2) |
| Diabetes mellitus |
16 (10.2) |
| Chronic obstructive pulmonary disease |
4 (2.6) |
| Renal insufficiency |
7 (4.5) |
| Cancer |
40 (25.5) |
| Cardiovascular disease |
33 (21.0) |
| Obese |
34 (21.7) |
| Inguinal hernia characteristics |
| No. inguinal hernias (N=201) |
|
| Hernia size (cm2) |
|
| Mean (±SD) |
5.1 (5.0) |
| Range |
0.3-30.3 |
| Hernia length [mean (±SD)] (cm) |
2 (1) |
| Hernia width [mean (±SD)] (cm) |
2 (1) |
| Inguinal hernia type (N=201), n (%) |
|
| Direct |
47 (23.4) |
| Indirect |
136 (67.7) |
| Other |
18 (9.0) |
BMI indicates body mass index.
Primary and Secondary Outcomes
Device endpoint events, including hernia recurrence, were to be site-reported as device-related and serious. Through 12 months, none of the 157 patients had serious device-related hernia recurrence, or device incidences of mesh erosion, infection, excision/removal, exposure, migration, shrinkage, device-related bowel obstruction, or fistula. Further, through 12 months, there were no reports of secondary (defined as device-related and serious) events of seroma, fistula, SSI, SSO, adhesion formation, bowel perforation, or unexplained/chronic pain for the 155 patients eligible for the secondary analysis.
Procedural endpoint events were to be site-reported as device-related or procedure-related. Through 30 days, none of the 157 patients had SSI, SSO, ileus, readmission, reoperation, or death.
Safety and PROs
A total of 13/157 (8.3%) patients had serious adverse events (including death) throughout and beyond 3 years of study. A total of 7 deaths were reported but were not related to the device or the procedure. The deaths occurred at the 6-month (n=1), 1-year (n=1), 2-year (n=2), 3-year (n=2), and beyond 3-year (n=1) time points. Causes of death were pneumonia-related (n=4), car accidents (n=1), heart surgery complications (n=1), and unknown (n=1). The remaining 6 serious adverse events were procedure-related and included 5 recurrent inguinal hernias (at 1 and 2 y) and 1 scrotal hematoma (at 6 mo).
Five nonserious procedure-related adverse events included urinary retention (n=2), seroma at 1 month (n=1), inguinal hernia recurrence at 6 months (n=1), and groin pain at 2 years (n=1).
Hernia Recurrence
Through 50 months and of the 201 hernias, 6 patients (2.98%) had a hernia recurrence that was study procedure-related; none were device-related. Half of the recurrences were within the first 12 months and the remainder were through 50 months. Of the 6 hernia recurrences, 5 were serious and were at the location of the device. Reoperation was required for 4 of the hernia recurrences.
Of the 6 hernia recurrences, 3 were within 12 months of which 2 were serious. The patient with recurrence on day 93 was minimally symptomatic and the event was not serious. Another patient developed an inguinal hernia on day 331 that required subsequent repair. The patient with recurrence on day 335 had a small hernia sac and large cord lipoma noted through the internal inguinal ring. The remaining 3 recurrences from 12 through 50 months were all serious. The recurrence on day 377 had an open repair in which cord lipoma was noted but no hernia sac was observed. One patient experienced 2 recurrences starting on day 471. The initial hernia was repaired with a 10×15 cm device. The first recurrence for this patient was repaired with a 15×20 cm device and the second recurrence required an open repair. Last, a patient with recurrence on day 555 developed urothelial carcinoma which required a cystectomy and prostatectomy at an outside institution, and any manipulation of the mesh during that procedure was not documented. As a result of the interval development of malignancy, additional hernia repair has not been performed.
PROs
The VHRI questionnaire was completed by 126 (80.3%) patients. The mean time from the procedure to completion of the questionnaire was 31 months (range: 15 to 50 mo). For the question “Do you feel or see a bulge at your treatment site?,” 6/127 (4.7%) of patients answered “yes” at any time during the 3 years. When queried “do you feel physical symptoms or pain at the site,” 10/126 (7.9%) of patients responded “yes.”
DISCUSSION
This study reviewed 157 patients with 201 inguinal hernias treated with a device for up to 3 years and adds to the body of evidence for the use of the IP hybrid biomaterial for inguinal hernia repair. In this series of patients, there were low rates of recurrence or postprocedure complications. Mesh implant selection is an important component of hernia repair, particularly when considering recurrence and postoperative complication which can have negative consequences in cost and quality of life.7–9 While the mesh device used is intended for IP placement, the implanting physician chose to implant in the preperitoneal plane with the nonporous film positioned adjacent to the peritoneum to promote peritoneum growth to protect the device from bowel adhesions. This placement aligns with the device instructions for use.3
Published rates of clinically reported or imaging-assessed recurrence following inguinal hernia repair with any mesh type ranges from 0.8% to 14%.1,2,10–12 In the current study, no serious, device-related hernia recurrence through 12 months occurred. Through 50 months of follow-up, the rate of any hernia recurrence was 3.0%, all were procedure-related, and half occurred in the first 12 months. Half of those undergoing subsequent repair were identified to have a cord lipoma causing the recurrent bulge and not representing a failure of the prior repair.
Groin pain is a commonly reported outcome of inguinal hernia repair and important to consider in terms of quality of life.13 In this retrospective study, groin pain captured as an adverse event was reported (at 2 y) in only 1 patient and was not serious. The VHRI measure was used to query “do you feel physical symptoms or pain at the site” to which 7.9% of patients responded “yes.” These lower rates of pain may, in part, be associated with the use of bridging for nearly all procedures. Placement of the mesh without primary closure of the defect is thought to decrease the chances of nerve entrapment and postoperative pain.14
There are options in mesh material and advantages and limitations to each. In this retrospective case series, all but 1 case was performed at a single site. This series evaluated only cases where the SYNECOR device was utilized for inguinal hernia repair. The site reported a preference for this device because of the material and construct of the device and because it was considered flexible and easy to handle. The 10×15 cm device was used for 75.9% of repairs. However, for larger hernias, 22.2% were repaired using the 15×20 cm device cut to 15×15 cm in size. While mesh materials can be cut down, the availability of a larger standard size for larger repairs that could be cut down to the appropriate size was appealing as it allowed the device to be tailored to the patient rather than be limited to just presized device materials.
LIMITATIONS
The study results should be considered in light of limitations. There is confidence in the data collected as the data are dependent on standard documentation for procedures as well as thorough chart review. Retrospective data collection is well represented in hernia mesh literature that attempts to describe long-term outcomes, particularly with recurrence and mesh explantation. Though this study included 4 clinical sites, all but 1 patient came from a single site. The clinical investigator was located in an area with limited options for hernia repair. As such, patients tended to return for follow-up.
The presentation of data as summary statistics were necessary as there were a low number of recurrence or adverse events that precluded statistical analysis. Though the sample size and number of reported events is low, the data provide an insight into outcomes of patients with inguinal hernia and a mesh-involved repair beyond 3 years.
The use of the PRO VHRI survey may be considered a limitation in the evaluation of inguinal hernia. The PRO was developed with a ventral hernia in mind but the concept of remotely querying subjects for readily observable symptoms to inform on the intensity of follow-up is a process in evolution for refinement within the inguinal hernia patient population. The instrument was shown to be a valid tool in the assessment of inguinal hernias.6
CONCLUSIONS
In this analysis, a majority of patients with inguinal repair with the use of a hybrid composite IP device had successful outcomes. These data showed low inguinal hernia recurrence and add to the body of evidence that this device has acceptable safety outcomes and device performance beyond 1 year.
ACKNOWLEDGMENTS
Millie Hollandbeck (Phoenix, AZ) provided medical writing assistance under the authors’ direction.
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