Partially Absorbable Mesh (SERATOM^® PA) for Vaginal Pelvic Organ Prolapse Surgery is a Safe and Effective Option: A Multi-Center and Prospective Study

Abstract

Objectives

This prospective multi-center pilot study evaluated the safety, efficacy, and quality of life (QoL) outcomes associated with the use of a transvaginal mesh kit utilizing partially absorbable mesh (PAM) in Korean women with pelvic organ prolapse (POP).

Methods

Thirty patients with symptomatic POP stage II or higher underwent surgical repair using the SERATOM^® PA mesh between March 2013 and February 2015. The primary endpoint was the objective surgical success rate, assessed by POP-Q stage and the need for repeat surgery within six months postoperatively. Secondary endpoints included QoL assessment using validated questionnaires (King’s Health Questionnaire, PFDI-20, PFIQ-7, and PISQ-12) and monitoring of complications.

Results

The mean participant age was 65.6 years, with 97% being postmenopausal. Preoperative POP-Q staging revealed that most patients (87%) had stage III or IV prolapse. The average surgical time was 96.4 minutes, and hospital stay averaged 4.9 days. No intraoperative or postoperative complications were reported. Of the 24 patients who completed follow-up, 23 achieved POP-Q stage 0 at six months, with the remaining patient at stage I but asymptomatic, requiring no further intervention. No cases of healing abnormalities or reoperations were noted. Significant improvements in pelvic floor dysfunction symptoms and sexual function were observed, as evidenced by marked improvements in PFDI-20, PFIQ-7, and PISQ-12 scores at six months postoperatively.

Conclusions

The use of PAM in transvaginal POP surgery demonstrated high efficacy, excellent safety outcomes, and significant improvement in QoL, suggesting it is a viable surgical option for advanced POP in this patient population.

INTRODUCTION

Pelvic organ prolapse (POP) is a common pelvic floor disorder affecting about one third of women [1]. Women in the United States have a 13% lifetime risk of undergoing surgery for a POP [2]. The peak incidence of POP symptoms is in women aged 70–79 years [3]. Aging and childbirth are considered the most important risk factors for POPs. Parity and conditions that can increase intra-abdominal pressure, such as heavy lifting, obesity, chronic constipation, and chronic coughing are also known risk factors of POPs [4,5,6]. Therefore, the incidence of POP is anticipated to increase with the worldwide trend of increasing life expectancy, especially in females, and the increasing incidence rate of obesity. It is anticipated that by 2050 the number of women experiencing a POP will increase by approximately 50% [7] and the quality of life (QoL) of women with a POP is significantly impaired and is even related to depression [8].

For advanced POPs, surgical options for pelvic reconstruction have been continuously developed and attempted. Traditionally, anterior colporrhaphy; posterior colporrhaphy, with or without hysterectomy and abdominal sacral colpopexy; uterosacral ligament suspension and sacrospinous fixation have been the main surgical options. However, high recurrence rates between 6% and 40% in native tissue repairs [9,10] have raised the need of other treatment options, including the introduction of biologic or synthetic grafts. The low recurrence rates reported in POP surgeries with mesh or a synthetic graft, especially in anterior compartment prolapses, as compared with native tissue repairs in Cochrane review [11], and the relatively easy technique of mesh kits has made us believe this is a promising surgical option. However, high complication rates, including healing abnormalities and sometimes pain and dyspareunia [12,13,14,15,16], led to the U.S. Food and Drug Administration publishing a warning regarding the use of mesh for vaginal prolapse repair in July 2011 [17]. A healing abnormality is the most frequent complication, occurring from 2% to up to 25% [9,18,19]. The most important factor of mesh related adverse events is thought to be the mesh itself, as is the same in sacrocolpopexy [20]. The material and weight of the mesh used for reconstructive surgery is a risk factor because it is hypothesized that exposure rates are correlated to the mesh weight and the amount of foreign material implanted [21].

Therefore, the lighter, thinner, smaller and more tissue compatible meshes with larger pores might be more suitable for POP surgery, with low complication rates as well as low recurrence rates. To accomplish an ideal condition of mesh, a partially absorbable mesh (PAM) was designed. Adding materials that are absorbed after implantation to the human body resulted in a weight reduction without an impairment of the supporting strength. However, there has been limited clinical evidence on the safety and efficacy until now [22,23]. The recently introduced PAM SERATOM^® PA (SERATEX^® PA B2 type; Serag-Wiessner KG) is supported by long-term successful use in randomized clinical studies performed in Europe [24]. A lower rate of healing abnormalities in the PAM as compared to a conventional polypropylene mesh, while maintaining a good anatomical outcome and patient satisfaction, was reported [24]. Therefore, this pilot study was performed to evaluate the safety, efficacy and effect on QoL of a transvaginal mesh kit with PAM in Korean patients with POPs.

MATERIALS AND METHODS

Thirty patients were included in this prospective multicenter pilot study, which was conducted in 3 university hospitals in Korea (Asan Medical Center, Korea University Guro Hospital, and Ewha Womans University Mokdong Hospital) from March 2013 to February 2015. Patients with a symptomatic POP-quantification (POP-Q) of at least stage II were treated by a transvaginal surgical mesh (TVM) kit with a PAM (SERATOM^® PA); a monofilament, knitted from a segmented partially absorbable monofilament composed from absorbable Poly (glycolide-co-caprolactone, 75/25) (PGA-PCL) copolymer and non-absorbable polypropylene part. After absorption of the absorbable part within 90–110 days after implantation, a light and soft polypropylene mesh (28 g/m²) remains. Meshes having either 4 or 6 arms were implanted through a conventional transobturator approach, as previously described [25].

Each patient underwent a thorough history taking, including detailed urogynecologic, medical and surgical histories, including symptoms of stress urinary incontinence (SUI), anal incontinence and POP. The degree of prolapse was determined using the original version of the International Continence Society POP-Q staging system.

Under general or spinal anesthesia in the dorsal lithotomy position, a TVM surgery was performed following the description of Fatton et al. [26]. Concomitant surgical treatments, including posterior colporrhaphy, anti-incontinence surgeries and sacrospinous fixations, were decided by the surgeons considering each patient’s symptoms, physical examinations and urodynamic study results. None of the patients had previously undergone POP surgery using either mesh or graft materials. The Institutional Review Board (IRB) of each hospital (Asan Medical Center, Korea University Guro Hospital, and Ewha Womans University Mokdong Hospital) reviewed and approved this study (IRB no. 2013-0341).

Inclusion criteria

Patients who were eligible for this trial included women who were due to undergo pelvic reconstructive surgery for a symptomatic POP with a POP-Q stage of II or more, were aged 21 years or more, had a uterine size smaller than gestational 3 months, who were able to complete 6 months of clinical observation follow-up (FU) visits and provided informed consent.

Exclusion criteria

Patients who are obese with a body mass index (BMI) 30 kg/m² or more, a smoker, had uncontrolled diabetes, immunocompromised patients who are taking immune-suppressants, a history of previous pelvic irradiation or lower urinary tract malignancies, a current infection of the genitourinary system, had a use of steroids for ≥ 6 months or who had undergone anticoagulant treatment other than aspirin were excluded. Patients who were performing clean-intermittent catheterizations, were currently pregnant or expecting to be pregnant during the trial or women within the postpartum 12-month period were excluded. Women who underwent abdominal or pelvic surgery within the preceding 3 months, were planning an abdominal surgery in the trial period and women who had undergone previous pelvic reconstruction using a synthetic mesh were also excluded. Patients with a congenital genitourinary anomaly, medical conditions that could affect bladder function such as multiple sclerosis or spinal cord injury and those suspected of having a hypersensitivity to partially absorbable synthetic meshes were excluded.

Evaluation and follow-up schedule

The primary endpoint was to investigate the objective success rate of surgical treatment; POP-Q stage and the rate of repeat surgery for recurrent POPs during the postoperative 6-month period. Secondary endpoints were to compare QoL using the King’s Health Questionnaire, Pelvic Floor Impact Questionnaire (PFIQ), Pelvic Floor Distress Inventory (PFDI), and POP/Urinary Incontinence Sexual Questionnaire (PISQ) and to estimate operation-related complications throughout the postoperative 6 months. Details of complications, including healing abnormalities and de novo or worsening urinary or anal incontinence, were also collected.

Patients completed FU visits at 2 weeks, 3 months and 6 months postoperatively, along with POP-Q examinations (preoperatively and 3 and 6 months postoperatively), check for operation-related complications (2 weeks, 3 months, and 6 months postoperatively) and fill out QoL questionnaires (preoperatively and 6 months postoperatively).

Statistics

Paired t tests were used to compare preoperative and postoperative anatomic outcomes, and P values < 0.05 were considered statistically significant.

RESULTS

A total of 32 patients were screened for eligibility. Excluding 1 patient who withdrew informed consent before being admitted to the hospital for surgery, 31 patients were enrolled in this study and underwent transvaginal pelvic reconstructive surgery using a PAM. Among the 31 patients who were enrolled, 1 patient who had a BMI 37.2 kg/m² was excluded due to a violation of the exclusion criteria. Finally, 30 patients followed the study protocol and 29 women completed the postoperative 3 months of FU, with 24 women completing a postoperative 6 months FU period and were included in the final analysis. The reasons for FU losses were diverse and medical illnesses not related to the POP surgery or loss of contact were the most common reasons. The study design, including patient participation and FU, are summarized in Figure 1. Patient characteristics and preoperative POP-Q examination results are summarized in Table 1. The mean age of the participants was 65.6 years (56–75 years), 97% of all the women had vaginal deliveries with a mean parity of 3.1 and most participants (97%) were postmenopausal women. The preoperative POP-Q stages were stage III in 18 patients (60%), stage IV in 8 patients (27%), and stage II in 4 patients (13%). The difference in pre- and postoperative hemoglobin levels was analyzed. The mean ± standard deviation (SD) hemoglobin levels were 13.2 ± 1.2 mg/dL preoperatively and 11.7 ± 1.0 mg/dL postoperatively. The mean hospital stay interval was 4.9 ± 2.4 days and the mean surgical procedure duration was 96.4 minutes, including concomitant surgeries. In terms of anterior transobturator mesh with posterior colporrhaphy (n = 14), the median operation time for was 68.5 minutes (mean ± SD: 73.7 ± 25.8 minutes). The most frequently performed concomitant procedures were a posterior repair (87%) and transobturator midurethral vaginal tape for SUI (23%) (Table 2). There were no intraoperative or postoperative complications, including pulmonary or cardiovascular events. Evaluation of the primary outcomes was performed in the 24 patients who completed 6 months of postoperative FU (Table 3). Twenty-three (23/24) patients who completed the postoperative 3-month and 6-month FU were at POP-Q stage 0, with no cases of reoperation for POP recurrence and no cases of healing abnormalities. The exception was 1 patient who was POP-Q stage I at postoperative 6 months of FU, although there was no need for reoperation due to there being no related symptoms. Additionally, a total of 15 patients who were available for postoperative 1 year of FU were analyzed and there was an additional 1 patient who had a recurrence of POP-Q stage II. However it was not symptomatic and did not require reoperation. There were no cases of healing abnormalities, worsening urinary or anal incontinence at postoperative 6 months of FU.

Fig. 1. Summary of study design. FU: follow-up.

Table 1. Patient characteristics and preoperative POP-Q examination results.

Parameter		n = 30
Age (y)		65.6 ± 9.3
Parity		3.1 (0–7)
BMI (kg/m2)		24.7 ± 2.6
Vaginal deliveries		29/30 (97)
Menopause		29/30 (97)
Postmenopausal hormone therapy		0/30 (0)
Previous surgery		11/30 (37)
	LAVH	2/30 (7)
	TAH	5/30 (17)
	VH	1/30 (3)
	Subtotal hysterectomy	1/30 (3)
	Tubal ligation	3/30 (10)
	BSO	1/30 (3)
	Posterior colporrhaphy	1/30 (3)
	Caesarean section	1/30 (3)
	Appendectomy	1/30 (3)
Medical disease		22/30 (73)
	Hypertension	16/30 (53)
	Diabetes mellitus	7/30 (23)
	SUI	8/30 (27)
	Uterine myoma	2/30 (7)
	Hypothyroidism	2/30 (7)
	Hyperthyroidism	2/30 (7)
	Dyslipidemia	3/30 (10)
	Osteopenia	1/30 (3)
	Atrial fibrillation	1/30 (3)
	UUI	1/30 (3)
	Arthralgia	1/30 (3)
POP-Q stage
	II	4/30 (13)
	III	18/30 (60)
	IV	8/30 (27)

Data are presented as mean ± SD, mean (range), or number (%).

POP-Q: pelvic organ prolapse-quantification, BMI: body mass index, LAVH: laparoscopic assisted vaginal hysterectomy, TAH: total abdominal hysterectomy, VH: vaginal hysterectomy, BSO: bilateral salpingo-ophorectomy, SUI: stress urinary incontinence, UUI: urgency urinary incontinence, SD: standard deviation.

Table 2. Perioperative outcomes and concomitant procedures.

Perioperative outcome		Concomitant procedure	No. of patient (n = 30)
Preoperative Hb level	13.2 ± 1.2 mg/dL	Posterior colporrhaphy	26 (87)
Postoperative Hb level	11.7 ± 1.0 mg/dL	TOT	7 (23)
Operation time for TVM with posterior colporrhaphy	73.7 ± 25.8 min	VH	4 (13)
		Primary bladder repair	2 (7)
		Bladder reinforcement	1 (3)
		Anterior colporrhaphy	1 (3)
		LSO	1 (3)
		Dilatation, curettage and biopsy	1 (3)

Data are presented as mean ± SD or number (%).

Hb: hemoglobin, TOT: transobturator vaginal tape, TVM: transvaginal surgical mesh, VH: vaginal hysterectomy, LSO: left salpingo-ophorectomy, SD: standard deviation.

Table 3. Pre- and postoperative POP-Q scores and re-operation rates.

	POP-Q score				P1a	P2b	P3c	P4d
	Baseline (n = 24)	12 weeks postoprative (n = 24)	24 weeks postoprative (n = 24)	1 year postoprative (n = 15)
Aa	2.2 ± 0.8	–2.6 ± 0.6	–2.5 ± 0.6	–2.5 ± 0.6	< 0.0001	< 0.0001	0.126	< 0.0001
Ba	3.0 ± 1.5	–2.5 ± 0.7	–2.4 ± 0.7	–2.3 ± 0.8	< 0.0001	< 0.0001	0.249	< 0.0001
C	1.4 ± 2.8	–5.9 ± 0.5	–6.0 ± 0.5	–6.1 ± 1.8	< 0.0001	< 0.0001	0.328	< 0.0001
Ap	–0.4 ± 2.4	–2.7 ± 0.5	–2.7 ± 0.5	–2.8 ± 0.6	< 0.0001	< 0.0001	0.821	0.0012
Bp	0.4 ± 2.6	–2.6 ± 0.6	–2.6 ± 0.6	–2.8 ± 0.6	< 0.0001	< 0.0001	0.586	0.0001
Stage 0	-	24 (100)	23 (96)	13 (87)
Stage I	-	-	1 (4)	1 (7)
Stage II	4 (17)	-	-	1 (7)
Stage III	13 (54)	-	-	-
Stage IV	7 (29)	-	-	-

Data are presented as mean ± SD or number (%).

POP-Q: pelvic organ prolapse-quantification, SD: standard deviation, -: not applicable.

^aBaseline vs. postoperative 12 weeks; ^bbaseline vs. postoperative 24 weeks; ^cpostoperative 12 weeks vs. postoperative 24 weeks; ^dbaseline vs. postoperative 1 year.

In terms of QoL, comparison of the PFDI-20, PFIQ-7, and PISQ-12 scores preoperatively and postoperatively at 6 months revealed a significant improvement in pelvic floor dysfunction symptoms and sexual function (P < 0.05) (Table 4).

Table 4. Pre- and postoperative quality of life questionnaires.

	Baseline score (n = 30)	Postoperative 24 weeks score (n = 22)	P
PFDI-20	113.6 ± 64.0	34.0 ± 32.8	< 0.0001
PFIQ-7	110.6 ± 68.6	20.6 ± 22.7	< 0.0001
PISQ-12	30.7 ± 8.8a	34.1 ± 7.7b	0.0158

Data are presented as mean ± SD.

PFDI: Pelvic Floor Distress Inventory, PFIQ: Pelvic Floor Impact Questionnaire, PISQ: Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire, SD: standard deviation.

^an = 24; ^bn = 17.

DISCUSSION

This prospective multicenter pilot study revealed that the TVM kit with a PAM is a safe and effective surgical option for Korean POP patients. There were no cases of reoperation for the recurrence of POP, the primary endpoint of this study, and there were also no cases of healing abnormalities at the postoperative 6-month FU point. QoL significantly improved and discomfort related to the POPs improved postoperatively.

Vaginal repair with synthetic mesh or biologic graft augmentation aims to correct anterior wall prolapses, apical vaginal prolapses or both [27]. The introduction of vaginal mesh kits for POP surgery broadened the era of POP surgery. In addition, they benefited from shorter operation times and easier surgical skill requirements when compared with conventional surgical options for upper vaginal and apical POP, especially with sacrocolpopexy. In addition to that, low recurrence rates are also an advantage of vaginal mesh kits, especially when compared with native tissue anterior colporrhaphy for correction of anterior vaginal wall prolapses. However it is associated with increased morbidity [22], repeat surgery mainly for SUI or mesh exposure [28].

The superiority of surgery with mesh to surgery without mesh in anti-incontinence surgeries, in terms of the recurrence of SUI, is already established and has been confirmed again in a recent large scale study published in 2017 [29]. However, the safety issues, mainly a healing abnormality (mesh erosion) related with the use of mesh has become problematic and some synthetic meshes that reported a high rate of mesh-related complications have been removed from the market.

However, in terms of POP surgery, a review article on graft and mesh use in transvaginal prolapse repair included 70 articles, with 38 randomized trials that were reported recently [27]. The authors concluded that synthetic mesh, not biologic grafts, in augmentation of anterior wall prolapse repair improves anatomic outcomes and bulge symptoms when compared with native tissue repairs [27]. Mesh erosions requiring reoperation were 3%–8%, therefore, the authors favored the use of mesh in transvaginal prolapse repair for anterior compartment POPs, the most common form of POP [27]. Also, in a recent study including data from 524 patients who underwent a transvaginal Prolift^® mesh repair by an experienced surgeon in a single institution reported that the global reoperation rate was 11.6% and most of those were for urinary incontinence (6.9%) [30]. Reoperation for mesh-related complications (3.6%) and prolapse recurrence (3.0%) were relatively low, therefore, the authors emphasized the importance of an experienced surgical team and concluded that vaginal mesh kits for POP are a safe and effective option in a 3-year median FU period [30].

In addition to this, we have to consider not only the mesh related issues but also their lower recurrence rate and relatively shorter operation time when compared with traditional surgical options for POPs. The need of reoperation for POP recurrence can be more harmful in women of an older age than a healing abnormality, which can usually be managed with excision of the exposed mesh and a primary vaginal repair under local anesthesia. POP surgeries require longer surgical times when compared with anti-incontinence surgeries and reoperation for POP recurrence could cause older aged women to suffer more surgical and anesthesia related risks as well as additional medical costs.

The most important things to prevent healing abnormalities after vaginal surgery with mesh are the use of the right mesh and the identification and placement of the mesh on the right surgical plane; the avascular space between the bladder and anterior vagina for anterior prolapse repair. Therefore, the experience level of the surgeons (all 3 surgeons in this study have over 10 years of surgical experience in the area of urogynecology) is especially important for low complication rates, same as the previous study [31,32].

Although there are only a few reports on the clinical outcomes of surgeries using a PAM, in a recent study that included 250 patients, with a median FU duration of 20 months, the rate of reoperation was 8% [33]. Moreover, the rate of mesh exposure requiring operation was only 2%. The recurrence of prolapse was low (1.2%), so the authors concluded that a PAM is efficient and reliable with relatively low rates of re-intervention [33]. Herein, the majority of erosion reported to be high in previous reports, which is associated with the use of mesh, can be interpreted as minor complications not requiring surgery. We have to remember that the majority of cases requiring reoperation after POP surgery using mesh were for the correction of SUI and not mesh-related complications nor POP recurrence.

There being no cases of reoperation for SUI in this study could be partly explained with our practice pattern. As we know, the preoperative evaluation of SUI is advised for patients with symptoms or advanced stage of POP. We performed urodynamic studies preoperatively for these patients, and if urodynamic stress incontinence was noted, anti-incontinence surgery was performed at the time of POP surgery concomitantly.

The relatively short surgical time (73.4 minutes), including posterior colporrhaphy, is good for the older aged POP patients, and should be considered as an important factor in surgical decision making. Vaginal surgery, including vaginal repair with synthetic mesh, has an additional advantage in that it is possible to undertake with spinal anesthesia or local anesthesia, which are especially important for decreasing the risk of postoperative respiratory complications, such as atelectasis or sore throat that are commonly related with general anesthesia and endotracheal intubation. Although the findings are meaningful, the relatively short FU period limits the ability to assess long-term outcomes.

In this study, a pelvic reconstructive surgery for POP with a newly developed, large pore polypropylene PAM in an experienced surgical team can be a good surgical option, especially in older aged women or women with medical comorbidities who need a surgical option both with a short operation and anesthesia time and with a low recurrence rate. In conclusion, transvaginal POP surgery with a PAM is an effective and safe surgical option for POP and detailed counseling about the advantages and disadvantages of surgical options with patients is needed.