Does the Weight Matter? Short-Term Outcomes of Lightweight Versus Heavyweight Three-Dimensional Anatomical Mesh in Minimally Invasive Inguinal Hernia Repair

Abstract

Background:

The type of mesh used in inguinal hernia repairs remains controversial. There are limited data looking at specific mesh-related complications. The objective of this study is to assess postoperative 90-day outcomes in lightweight (LW) and heavyweight (HW) anatomical mesh in minimally invasive inguinal hernia repairs.

Methods:

A retrospective single-center database was queried for all adult minimally invasive inguinal hernia repairs with anatomical mesh from July 2016 to March 2021. Demographics and surgical outcomes were analyzed. Univariate analysis and multivariate logistic regression were performed.

Results:

Six hundred forty-seven minimally invasive inguinal hernia repairs were performed with 423 (65.3%) using HW and 224 (24.7%) using LW mesh. There was no difference in mean body mass index between the groups (26.9 ± 4.2 kg/m² in the LW group and 27.1 ± 4.2 kg/m² in the HW group; P = .69). There was no difference in type of mesh fixation used in either group, with tacker being the most common. There was no difference in postoperative emergency department (ED) visit (P = .625), readmission rates (P = .562), or postoperative complications between the two groups. Fifty patients presented with seroma within 90 days. There were five recurrences in each group and only one surgical site infection in the LW within 90 days. Multivariate logistic regression was performed, and predictors of seroma formation included age (odds ratio [OR] 1.02; confidence interval [CI] 1–1.04; P = .02) and hypertension (HTN) (OR 1.8; CI 1.03–3.4; P = .039). HW mesh was not associated with seroma formation (OR 1.04; CI 0.5–1.9; P = .895). Similarly, HW mesh was not associated with surgical site occurrences (SSO) (OR 1.04; CI 0.5–1.8; P = .872). HTN was associated with SSO (OR 1.74; CI 1–3.05; P = .048).

Conclusion:

Our study did not favor the use of LW or HW mesh when comparing postoperative complications or clinical outcomes. HW mesh was not associated with either seroma formation or SSO.

Introduction

Inguinal hernia repair is one of the most common surgical procedures performed annually in the United States with >700,000 procedures.¹ Permanent synthetic mesh repair has been the mainstay for inguinal hernia repairs independently of surgical technique.² International guidelines recommend the minimally invasive approach by seasoned surgeons and the use of mesh in all inguinal repairs irrespective of surgical approach or type of hernia.³ The use of mesh in inguinal hernia repairs significantly decrease recurrence rates when compared with suture repairs.^4–6

Anatomical meshes have been developed with the goal to accommodate the curvature of the inguinal area and helping with the handling and positioning. The Bard 3DMax™ is a three-dimensional anatomically contoured polypropylene mesh that requires either no or minimal fixation.² Furthermore, these new meshes were developed with the objective of decreasing mesh-related complications such as postoperative chronic pain and surgical site occurrences (SSO).^6,7

Although the decision to use mesh in inguinal hernia repairs is unanimous among surgeons, the type of mesh used remains controversial.⁸ There are limited data looking at specific mesh-related complications, including seroma, hematoma, infections, chronic pain, and hernia recurrence.^9–12 The objective of this study is to assess postoperative 90-day outcomes in lightweight (LW) and heavyweight (HW) anatomical mesh in minimally invasive inguinal hernia repairs.

Methods

Study design

This is a retrospective study with patients who underwent minimally invasive inguinal hernia repairs with lightweight (LW) or heavyweight (HW) anatomic mesh from July 2016 to March 2021 in an academic center. Adult patients who underwent laparoscopic- or robotic-assisted inguinal repairs were included in this study. This study was approved by the Institution Review Board number #11160 and all Health Insurance Portability and Accountability Act compliant mechanisms were followed.

Data collection

Institutional Review Board approval was obtained to conduct this study. Data were retrospectively collected and divided into sections: patient characteristics, hernia characteristics, perioperative data, and patient outcomes. Patient demographics and comorbidities were analyzed: age, body mass index (BMI), gender, hypertension (HTN), diabetes mellitus, smoking status, cardiovascular accident, dyslipidemia, liver disease, chronic obstructive pulmonary disease, chronic kidney disease, and American Society of Anesthesiology (ASA) class.

Perioperative data were collected on information regarding primary or recurrent hernia, surgical approach and technique, mesh size, mesh weight, operative time (OT), length of stay, type of mesh fixation, peritoneal closure, complications at 90 days, readmissions, ED presentation, and use of opioids.

Statistical analysis

A descriptive analysis was performed. Continuous variables were reported as mean and standard deviation (SD) or median and range. Categorical variables were reported as frequencies and percentages. Data were analyzed using the SPSS v.26 Chicago: SPSS, Inc. Pearson's χ² and the Fisher's exact test were used for categorical variables and the unpaired t-test or the Kruskal–Wallis test were used for parametric and nonparametric continuous data respectively. Univariate analysis was performed comparing 3D Max LW versus HW mesh. Then, a logistic regression was used to identify independent risk factors associated with SSO and seroma formation. Odds ratio (OR) with a corresponding 95% confidence interval (CI) was used to report the results of the models. A P value of <.05 was considered statistically significant.

Results

Patient characteristics comparing LW and HW anatomic mesh

A total of 647 minimally invasive inguinal hernia repairs were performed with 423 (65.3%) using HW and 224 (24.7%) using LW mesh. Patient characteristics are as listed in Table 1. Mean age was 55.3 (SD 14.3) for the LW and 57.1 (14.5) for the HW with no statistical difference between the groups (P = .124). There was no difference in mean BMI between the groups (26.9 ± 4.2 kg/m² in the LW group and 27.1 ± 4.2 kg/m² in the HW group; P = .69). Comorbidities and smoking status were similar between the groups. Prior inguinal hernia repair was similar between the groups. Most patients were ASA II and there was no difference between the groups (P = .795).

Table 1.

Patient Characteristics

	LW (n = 224)	HW (n = 423)	P
Mean age (SD)	55.3 (14.3)	57.1 (14.5)	.1245
Mean BMI (SD)	26.9 (4.2)	27.1 (4.2)	.69
Gender, n (%)			.87
Male	203 (90.6)	385 (91)
Female	21 (9.4)	38 (9)
HTN	99 (44.2)	186 (44)	.956
DM	30 (13.4)	75 (17.7)	.155
CAD	13 (5.8)	29 (6.8)	.605
DLP	48 (21.4)	138 (23.6)	.003
Liver disease	14 (34.6)	11 (2.6)	.02
COPD	7 (3.1)	9 (2.1)	.437
CKD	12 (5.3)	21 (4.9)	.829
Smoking, n (%)			.131
Former	57 (25.4)	111 (26.2)
Current smoker	49 (21.9)	66 (15.6)
Previous repair	23 (10.3)	56 (13.2)	.587
Bilateral hernia	56 (25)	152 (35.9)	.003
ASA, n (%)			.795
I	44 (19.6)	73 (17.3)
II	137 (61.2)	267 (63.1)
III	41 (18.2)	81 (19.2)
IV	2 (1)	2 (0.4)

ASA, American Society of Anesthesiology; BMI, body mass index; CAD, coronary artery disease; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; DLP, dyslipidemia; DM, diabetes mellitus; HTN, hypertension; HW, heavyweight; LW, lightweight; SD, standard deviation.

Operative details

The laparoscopic approach was the most commonly used approach in both groups (Table 2). Sixty four patients (28.6%) with LW mesh underwent the robotic approach compared with 83 (19.6%) of the HW group (P = .01). Totally extraperitoneal (TEP) was the most commonly used surgical technique in both groups with no difference between the two. There was no difference in type of mesh fixation used in either group, with tacker being the most common. In addition, there was no difference in peritoneal closure between the groups. When analyzing cases with peritoneal closure, barbed suture was most commonly used. Mean OT was 102.9 (±48.8) minutes in the HW group and 92.5 (±47) minutes in the LW group (P = .009).

Table 2.

Perioperative Outcomes

	LW (n = 224)	HW (n = 423)	P
Surgical approach, n (%)			.01
Laparoscopic	160 (71.4)	340 (80.4)
Robotic	64 (28.6)	83 (19.6)
Mesh size, n (%)			<.001
Medium	14 (6.2)	80 (18.9)
Large	208 (92.9)	220 (52)
Extra large	2 (0.9)	123 (29.1)
Surgical technique, n (%)			.28
TAPP	88 (39.3)	148 (35)
TEP	136 (60.7)	275 (65)
Mean OT (SD)	92.5 (47)	102.9 (48.8)	.009
Mean LOS (SD)	0.1 (0.5)	0.2 (1.2)	.196
Abandon the sac, n (%)	2 (0.9)	4 (1)	.947
Peritoneal closure, n (%)			.083
Suture not barbed	0 (0)	6 (1.4)
Barbed suture	75 (34)	112 (29.1)
Tacker	14 (6.3)	26 (6.2)
NR	132 (59.7)	275 (65.8)
Mesh fixation, n (%)			.103
No fixation	57 (25.4)	127 (30)
Suture	55 (24.6)	94 (22.2)
Tacker	112 (50)	194 (45.8)
Suture and tacker	0 (0)	8 (1.9)
TAP block, n (%)	14 (6.2)	36 (8.5)	.306

HW, heavyweight; LOS, length of stay; LW, lightweight; NR, not reported; OT, operative time; SD, standard deviation; TAP, transversus abdominis plane; TAPP, transabdominal preperitoneal; TEP, totally extraperitoneal.

Postoperative outcomes

There was no difference in postoperative ED visit (P = .625), readmission rates (P = .562), or postoperative complications between the two groups. Fifty patients presented with seroma within 90 days. There were five recurrences in each group and only one surgical site infection in the LW within 90 days. Postoperative outcomes are as listed in Table 3.

Table 3.

Postoperative Outcomes

	LW (n = 224)	HW (n = 423)	P
Postoperative opioid, n (%)	208 (92.8)	367 (86.7)	.019
Postoperative nonopioid meds, n (%)	82 (36.6)	133 (31.4)	.185
ED presentation, n (%)	25 (11.2)	42 (9.9)	.625
Readmission, n (%)	3 (1.3)	2 (0.5)	.562
Clavien–Dindo classification, n (%)			.874
No complication	195 (87.1)	366 (86.7)
Grade I	24 (10.7)	45 (10.6)
Grade II	2 (0.9)	3 (0.7)
Grade IIIa	0 (0)	2 (0.5)
Grade IIIb	3 (1.3)	7 (1.6)
Complications within 90 days, n (%)
Seroma	17 (7.6)	33 (7.9)	.514
Hematoma	2 (0.9)	7 (1.7)	.339
Recurrence	5 (2.2)	5 (1.2)	.243
SSI	1 (0.4)	0 (0)	.349
New groin mass	0 (0)	1 (0.2)	.651
Urinary retention	5 (2.2)	8 (1.9)	.495
Neuralgia	1 (0.4)	0 (0)	.349
Hydrocele/hematocele	1 (0.4)	1 (0.2)	.576

ED, emergency department; HW, heavyweight; LW, lightweight; SSI, surgical site infection.

Multivariate analysis

Multivariate logistic regression was performed to control for confounding variables regarding SSO and seroma formation. Factors that we believed could be possible confounding variables were included in the model. Analysis is as listed in Table 4. Predictors of seroma formation included age (OR 1.02; CI 1–1.04; P = .02) and HTN (OR 1.8; CI 1.03–3.4; P = .039). HW mesh was not associated with seroma formation (OR 1.04; CI 0.5–1.9; P = .895). Similarly, HW mesh was not associated with SSO (OR 1.04; CI 0.5–1.8; P = .872). HTN was associated with SSO (OR 1.74; CI 1–3.05; P = .048). Logistic regression is shown in Table 4. No other factor was associated with either seroma formation or SSO.

Table 4.

Logistic Regression

Logistic regression	OR (95% CI)	P
Seroma formation
Age	1.02 (1–1.04)	.02
Male gender	1.7 (0.5–5.7)	.33
BMI	1.03 (0.9–1.1)	.33
HTN	1.8 (1.03–3.4)	.039
DM	0.5 (0.2–1.38)	.218
Current smoker	0.5 (0.2–1.3)	.169
HW	1.04 (0.5–1.9)	.895
Any SSO
Age	1.01 (0.9–1.03)	.084
Male gender	2.09 (0.6–6.8)	.225
BMI	1.02 (0.9–1.09)	.358
HTN	1.75 (1–3.05)	.048
DM	0.6 (0.3–1.5)	.344
Current smoker	0.5 (0.2–1.1)	.115
HW	1.04 (0.5–1.8)	.872

BMI, body mass index; CI, confidence interval; DM, diabetes mellitus; HTN, hypertension; HW, heavyweight; OR, odds ratio; SSO, surgical site occurrence.

Discussion

Permanent synthetic mesh repair has been the backbone of inguinal hernia repairs regardless of surgical approach. Theoretical advantages of LW mesh over HW mesh have been proposed: decreased rates of infection, improved quality of life, and limited mesh contraction.^10,13 In our study we compared LW with HW polypropylene anatomical meshes for minimally invasive inguinal hernia repair. There was no difference in postoperative complications between both meshes within 90 days. Logistic regression showed that age was a predictor of seroma formation. However, HW mesh was not associated with either seroma formation or SSO.

There was no difference in age, BMI, or recurrence rates between both groups. Patient sociodemographic variables were similar between the two groups. Regarding intraoperative outcomes, there was no difference in mesh fixation or peritoneum closure between groups. Furthermore, there was no difference in surgical technique (transabdominal preperitoneal [TAPP] or TEP) between the groups. Patient population was similar between the two groups and with a minimal variability in surgical technique among the surgeons involved in these procedures.

Our findings corroborate with the findings from Heniford and colleagues.⁸ In this study, the authors evaluated the use of LW versus HW mesh in 1424 patients who underwent laparoscopic inguinal hernia repair. In their study, there was no difference in complications between the groups. Seroma appeared to occur more in HW mesh, but logistic regression showed no association between HW mesh and seroma formation. As opposed to this study, our study did not evaluate postoperative quality of life.

Kudsi et al.² compared different types of mesh in patients who underwent robotic inguinal hernia repair. The authors performed a Propensity Score Matched analysis between 262 patients divided in two groups: one that had 3DMax mesh and another with a self-gripping polyester mesh.² They found no difference in terms of postoperative complications, clinical outcomes, or hospital costs. The authors reported only two recurrences in the polyester group.

LW mesh was developed with the objective of decreasing foreign body mass and, with larger pore sizes between filaments, less inflammation and mesh contraction. This would decrease patient discomfort and mesh-related complications. However, Heniford and colleagues⁸ found no difference in short-term complications between LW and HW meshes. In addition, they showed that LW mesh was not associated with seroma formation. Prior literature regarding inguinal hernia repair and mesh have mostly analyzed the Lichtenstein repair. In addition, these have tended to be short-term studies.^7,10–15 Our study is the first to include the robotic approach when evaluating the weights of polypropylene mesh and their effects on postoperative results.

In our study, we had 14 patients in the LW mesh group and 80 in the HW mesh group with medium size meshes. According to the most recent guidelines, the medium size anatomical mesh is not indicated.³ Mesh shrinkage of at least 20% must be accounted for depending on the structure of the mesh and tissue response. Surgeons should take this into consideration before performing inguinal hernia repairs. In our center, most cases using medium size mesh were performed from 2016 to 2018, with a considerable decrease afterward. After review of our data, we recommended the use large or extra-large mesh to surgeons from our department.

Our seroma rate was similar between groups with 7.6% in the LW group and 7.9% in the HW group. The seroma rate in the HW group is lower than that published by Heniford and colleagues. The authors found a 21.5% seroma rate in the HW mesh group. Heikkinen et al. looked at 137 patients with recurrent unilateral inguinal hernias that underwent TEP repair with LW versus HW mesh. They found no difference in postoperative outcomes within 8 weeks after surgery.¹⁶ Koch et al. performed an RCT of going hernia repair in 317 patients with titanium-coated LW mesh versus standard polypropylene mesh.

There were no differences in seroma formation or hematoma.¹⁷ Three RCTs compared self-gripping polyester mesh to conventional polypropylene mesh. There were no advantages to one type of mesh over the other.^18–20 In our study, we had five readmissions. Two in the HW mesh group due to large hematoma and 3 in the LW mesh group, 1 due to a large hematoma, 1 patient with testicular pain, and 1 with a painful scrotal swelling. All patients were managed conservatively.

Limitations

This study has several limitations. It is a retrospective single-center study with short follow-up. Most of the procedures were performed by 2 dedicated hernia surgeons and there was minimal variability in the surgical technique or approach. Surgeons used tackers, suture, glue, and chose between LW or HW mesh according to their personal preference. Selection bias and performance bias may be present.

Conclusion

Our study did not favor the use of LW or HW mesh when comparing postoperative complications or clinical outcomes. HW mesh was not associated with either seroma formation or SSO. Regarding seroma formation, associated factors included age and HTN. Whereas just HTN was associated with SSO. Longer-term follow-up is necessary to evaluate recurrence rates between the two mesh types.

Footnotes

Authors' Contributions

Study design by D.L.L., F.M., and P.S. Data collection and analysis by D.L.L., V.V., R.N., J.P.G.K., and R.B. Article preparation and editing by D.L.L., F.M., P.S., R.N., V.V., J.G.P.K., and R.B.

Disclosure Statement

D.L.L., P.S., V.V., R.N., J.P.G.K., and R.B. disclose no conflict of interest. F.M. discloses consulting fees from BD, Intuitive, Integra, DeepBlue, Allergan & Medtronic, outside the submitted study.

Funding Information

No funding was received for this article.

References

Rutkow

. Demographic and socioeconomic aspects of hernia repair in the United States in 2003. Surg Clin North Am, 2003; 83,(5):1045–1051, v–vi.

Kudsi

, Kaoukabani

, Bou-Ayash

, et al. Does the mesh type influence the outcomes and costs of robotic inguinal hernia repair?. J Robot Surg, 2022; 17,(3):971–978.

HerniaSurge Group. International guidelines for groin hernia management. Hernia, 2018; 22,(1):1–165.

van Veen

, Wijsmuller

, Vrijland

, et al. Long-term follow-up of a randomized clinical trial of non-mesh versus mesh repair of primary inguinal hernia. Br J Surg, 2007; 94,(4):506–510.

Fränneby

, Sandblom

, Nordin

, et al. Risk factors for long-term pain after hernia surgery. Ann Surg, 2006; 244,(2):212–219.

Lockhart

, Dunn

, Teo

, et al. Mesh versus non-mesh for inguinal and femoral hernia repair. Cochrane Database Syst Rev, 2018; 9(9):CD011517.

Nienhuijs

, Staal

, Strobbe

, et al. Chronic pain after mesh repair of inguinal hernia: A systematic review. Am J Surg, 2007; 194,(3):394–400.

Arnold

, Coakley

, Fromke

, et al. Long-term assessment of surgical and quality-of-life outcomes between lightweight and standard (heavyweight) three-dimensional contoured mesh in laparoscopic inguinal hernia repair. Surgery, 2019; 165,(4):820–824.

Bittner

, Leibl

, Kraft

, et al. One-year results of a prospective, randomised clinical trial comparing four meshes in laparoscopic inguinal hernia repair (TAPP). Hernia, 2011; 15,(5):503–510.

10.

Weyhe

, Belyaev

, Müller

, et al. Improving outcomes in hernia repair by the use of light meshes—A comparison of different implant constructions based on a critical appraisal of the literature. World J Surg, 2007; 31,(1):234–244.

11.

O'Dwyer

, Kingsnorth

, Molloy

, et al. Randomized clinical trial assessing impact of a lightweight or heavyweight mesh on chronic pain after inguinal hernia repair. Br J Surg, 2005; 92,(2):166–170.

12.

Prakash

, Bansal

, Misra

, et al. A prospective randomised controlled trial comparing chronic groin pain and quality of life in lightweight versus heavyweight polypropylene mesh in laparoscopic inguinal hernia repair. J Minim Access Surg, 2016; 12,(2):154–161.

13.

Cobb

, Kercher

, Heniford

. The argument for lightweight polypropylene mesh in hernia repair. Surg Innov, 2005; 12,(1):63–69.

14.

Paajanen

. A single-surgeon randomized trial comparing three composite meshes on chronic pain after Lichtenstein hernia repair in local anesthesia. Hernia, 2007; 11,(4):335–339.

15.

Bringman

, Wollert

, Osterberg

, et al. Three-year results of a randomized clinical trial of lightweight or standard polypropylene mesh in Lichtenstein repair of primary inguinal hernia. Br J Surg, 2006; 93,(9):1056–1059.

16.

Heikkinen

, Wollert

, Osterberg

, et al. Early results of a randomised trial comparing Prolene and VyproII-mesh in endoscopic extraperitoneal inguinal hernia repair (TEP) of recurrent unilateral hernias. Hernia, 2006; 10,(1):34–40.

17.

Koch

, Bringman

, Myrelid

, et al. Randomized clinical trial of groin hernia repair with titanium-coated lightweight mesh compared with standard polypropylene mesh. Br J Surg, 2008; 95,(10):1226–1231.

18.

Kingsnorth

, Gingell-Littlejohn

, Nienhuijs

, et al. Randomized controlled multicenter international clinical trial of self-gripping Parietex^TM ProGrip^TM polyester mesh versus lightweight polypropylene mesh in open inguinal hernia repair: Interim results at 3 months. Hernia, 2012; 16,(3):287–294.

19.

Jorgensen

, Sommer

, Assaadzadeh

, et al. Randomized clinical trial of self-gripping mesh versus sutured mesh for Lichtenstein hernia repair. Br J Surg, 2013; 100,(4):474–481.

20.

Mitura

, Garnysz

, Wyrzykowska

, et al. The change in groin pain perception after transabdominal preperitoneal inguinal hernia repair with glue fixation: A prospective trial of a single surgeon's experience. Surg Endosc, 2018; 32,(10):4284–4289.