Mesh safety in pelvic surgery: Our experience and outcome of biological mesh use

INTRODUCTION

The aim of this study was to investigate the outcomes of LVMR using a biologic mesh in a district general hospital in an era where there is concern regarding the placement of pelvic mesh. We assessed the outcome of the procedure in relation to complications, bowel function and recurrences of symptoms following surgery.

Over the last few years there have been concerns about the usage of meshes in pelvic surgery, especially since serious complications have been recorded in urogynaecology procedures where trans-vaginal placement of mesh in women was used to treat pelvic organ prolapse. This led many countries to scrutinise the use of mesh. This was particularly the case in the United Kingdom with the Scottish Government being the first to halt the use of trans-vaginal mesh in 2014[3]. However the incidence of meshrelated complications, and particularly mesh erosion, after LVMRs is low, especially when a biological mesh is used[4]. This was shown by Balla[4] in their review of literature where they demonstrated that the synthetic and the biological mesh-related erosion rates were 1.87% and 0.22%, respectively.

To assess the safety of the mesh and the outcome of the procedure.

Laparoscopic ventral mesh rectopexy (LVMR) has recently become the preferred treatment for full thickness rectal prolapse, and it has been also widely used in the treatment of rectoceles, enteroceles and rectal intussusception with associated symptoms of obstructive defecation with or without faecal incontinence[1]. The procedure has good short term and long term results with minimum morbidity rates and low recurrence rates[2], particularly when compared to the perineal surgical approach used for treatment of rectal prolapse[2]. In addition, due to reduced postoperative complications, a shorter length of hospital stay is an advantage[1,2].

MATERIALS AND METHODS

Laparoscopic ventral mesh rectopexy is becoming one of the leading treatment options for the elective repair of rectal prolapse around the world[6,7]. Perineal procedures are still performed especially for elderly patients and those with associated significant comorbidity who are not candidates for transabdominal laparoscopic procedures[8,9].However, there are recent studies that demonstrate that LVMRs would be safe for selected elderly patients as well[10]. In our series, there were 5 elderly patients over 80 that had a successful procedure with a good outcome.

The functional outcomes for these patients were calculated using the Wexner scoring system for constipation and incontinence before and after surgery. All patients had a follow-up appointment in the clinic 3 mo after surgery and further follow-up 6-12 mo later. We also reviewed the notes on average 18.3 ± 4.2 mo after the procedure.Clinical outcomes of surgery and any complications resulting from surgery were recorded in the Pelvic Floor Society hosted national database.

子程序上电初始化把程序全部复位，其作用在于使系统做好工作准备，降低程序死循环的可能性，增加系统可靠性[4-5]。

Surgical technique

At University Hospital Wishaw all LVMR procedures from June 2012 to August 2018 were performed by the same colorectal surgeon. After creating pneumoperitoneum and inserting the working ports (12 mm port on the right iliac fossa, 5 mm supra umbilical port and a 5 mm port in the right abdomen, the pelvic peritoneum at sacral promontory was opened using hook diathermy and continued distally and anteriorly down to the level of the levator muscles, while preserving the lateral ligaments and the hypogastric and sacral nerves. The biological porcine skin mesh that was used for all cases (permacol 4 × 18 cm long and 1 mm thick) was sutured as distally as possible onto the anterior rectal wall using interrupted seromuscular nonabsorbable sutures (2-0 Ethibond, Ethicon Endosurgery, Raritan, NJ, United States) and the upper part of the mesh was fixated to the sacral promontory using 4-5 spiral attachments (Pro-TackFixation Device, Medtronic, Dublin, Ireland). Also, the gap between vagina and mesh was closed in women using 2.0 PDS (Figure 1).

The peritoneum was closed over the mesh with a continuous suture (V-lock 180, 15 cm). Perioperative care was conducted per the enhanced recovery after surgery protocol. A urinary catheter was inserted after the patient was anesthetised and was removed on the first post-operative day.

Statistical analysis

It is evident that our study demonstrates a significant improvement of patients’symptoms of obstructive defecation. The median post-operative Wexner score for constipation was 3 (IQR: 1-6) compared to the median pre-operative score which was 14.5 (IQR: 10.5-18.5), demonstrating a significant improvement (0.01). These results are comparable to the results of Franceschilli[18] who demonstrated that the mean Wexner score for constipation improved from 18.4 ± 11.6 to 5.4 ± 4.1 (= 0.04).Comparing the average pre-operative Wexner score for incontinence (11, IQR: 7-15) to the median post-operative score for incontinence (2, IQR: 0-5), there was also a significant improvement demonstrated (0.01).

RESULTS

A total of 86 patients underwent LVMR from June 2012 to August 2018. Eighty-two(95%) were female and 4 (5%) were male with a median age of 57 years (IQR: 47-70).The median hospital stay was 1 d (IQR: 1-2). The first follow-up of the patients was at 3 mo, and the second one was 6-12 mo after surgery.

The pre-operative Wexner scores were calculated during the first visit to the clinic,usually 6-9 mo prior to surgery, while the post operative Wexner scores for constipation and incontinence were calculated on forms filled in during the consecutive follow-up appointment with the patient and in some cases over a telephone conversation with the patient by one of the surgical team members. Out of the 86 patients, pre-operative data were obtained for 86 patients, while post-operative Wexner score was obtained for 80 patients, since 6 of them did not return the forms.For these 80 patients the median post-operative Wexner score for constipation was 3(IQR: 1-6), which was significantly improved compared to the median pre-operative score for constipation which was 14.5 (IQR: 10.5-18.5) (0.01). Again, comparing the median pre-operative Wexner score for incontinence, which was 11 (IQR: 7-15), to the median post-operative score for faecal incontinence, which was 2 (IQR: 0-5), there was also a significant improvement demonstrated (0.01) (Table 2).

All the procedures were completed laparoscopically, and there was no surgery related mortality recorded. No mesh related infection or erosion was recorded,although there was 1 case of diskitis that had to be treated with antibiotics after seen in the clinic for a follow-up. One of the patients developed an incarcerated femoral hernia post-surgery, which was seen intraoperatively but not repaired since the patient was not consented for that procedure, and it was repaired on day 2. Out of the 86 patients, 3 (3.4%) had issues with chronic pelvic pain after the procedure. Two of the patients complained of a foreign body sensation/irritation in rectum and were found to have a suture protruding through the rectum that was removed in clinic, which was followed by immediate relief of their symptoms. Out of the 86 patients, 4 (4.6%) of them came back with a recurrence of symptoms, 3 (2.3%) of which had a posterior prolapse recurrence and 2 of which eventually underwent a modified Delorme’s procedure.

Overall recurrence at 12 mo was estimated with the Kaplan-Meier method as 1.4%(95%CI: 0.3%#4.0%), 7% (95%CI: 6.1%#15.5%) at 2 years and 11% (95%CI: 6.7%#16.8%)at 3 years (Figure 2).

DISCUSSION

This is a retrospective study of 86 consecutive patients that underwent LVMR from June 2012 to August 2018 in University Hospital of Wishaw. For 40 of them obstructive defecation was the main symptom, for 38 it was both obstructive defecation and faecal incontinence, 5 (5.8%) presented with pain and bleeding related to full thickness rectal prolapsed and 3 with mainly symptoms of faecal incontinence. All patients had a full history and physical examination, and a lower gastrointestinal endoscopic assessment.All, except those with obvious full thickness rectal prolapse, underwent a defecating proctogram, while 9 of them (10%) had anorectal physiology studies. Seven (0.08%)patients with not so clear symptoms and findings required an examination of the anorectum under general anaesthesia prior to the procedure. A detailed obstetric and pelvic surgery history was taken for women, and following formal development of Pelvic Floor multidisciplinary, all the patients were discussed on a monthly basis at the pelvic floor multidisciplinary team (Table 1).

When LVMRs are compared to resectional and posterior rectopexies, the functional results are better, especially since there is no interference with the sacral nerves and therefore fewer issues with slow transit constipation[11]. Other surgical procedures such as stapled transanal rectal resection can be used for rectal intussusception and obstructive defecation secondary to rectoceles as an alternative surgical approach to laparoscopic ventral mesh rectopexy[12]. However, this procedures has been associated with higher morbidity rates including pain, haemorrhage and sepsis[13].

Over the past years there has been a major concern over the use of mesh in pelvic surgery, but in our series of patients so far there were no mesh related complications,such as mesh erosion or infection. This is likely due to the consistent use of biological mesh in all of our cases, and our findings therefore come in agreement with previous studies’ findings that the mesh related complications are far less when using a biologic mesh instead of a synthetic one[4]. Although our directly obtained data of follow-up were for 1 year after surgery, the fact that there was only one colorectal surgeon that provides such surgery in Lanarkshire combined with the absence of re-referrals of previously operated patients for symptoms related to mesh complication, indirectly suggests that there was no mesh complication over a period of 5 years. Balla[4]have shown after reviewing the literature that using a biological mesh is a safer option than using a synthetic one, especially since the synthetic and the biological meshrelated erosion rates were 1.87% and 0.22%, respectively.

Although there was an initial concern that using biological mesh might be associated with higher recurrence rate, it has been demonstrated that there was no difference in recurrence when using a biological mesh compared to a synthetic one[11]. It has also been suggested that biological mesh should be preferred in patients with a high risk of fistula formation, such as those with diverticular disease, Crohn's disease, previous pelvic irradiation and steroid use[12]. Additionally, in another study,Mercer-Jones[13] suggested it could be prudent to use a biological mesh in young adolescents or women of child-bearing age regardless of the higher cost.

Complications were observed in the current study. Lumbosacral discitis near the site of mesh fixation to the sacral promontory was observed in 1 patient. This is a rare but serious complication with patients typically presenting 1-3 mo after the initial operation with severe lower back pain, fever and malaise[14]. In this case, magnetic resonance imaging confirmed the diagnosis, and broad spectrum antibiotics were given as they are the treatment of choice[14,15]. Although an uncommon complication,it should always be considered for patients that present with lower back pain after an LVMR[14,15]. Two patients presented with rectal symptoms of discharge and discomfort and were found to have ethibond suture erosion into their rectum. This is likely related to the suturing technique or the material itself, although there is no report of this complication in the literature so far[16]. In both patients, symptoms improved dramatically after transanal removal of sutures at outpatient/endoscopy room.

In conclusion, our study adds more evidence to support that LVMR using biological mesh is a safe and effective procedure for the treatment of rectal prolapse and that it significantly improves bowel symptoms of obstructive defecation and faecal incontinence in patients with not only full thickness prolapse but also internal rectal prolapse and rectoceles[6,7,17,19]. In our study there were no mesh related complications, and this result correlates with the low biological mesh complication rate reported in other studies[4,13]. Our recurrence rates are in line with the ones reported in the literature[16], and although we acknowledge that the direct follow-up period was short, the absence of re-referral of those previously operated patients over the period of 5 years would indirectly suggest the safety of the mesh over longer periods.However, our continued effort is to follow this group of patients more directly and continue to assess formally their quality of life in the near future.

此外，对于延伸组分除只按碳数进行归类外(处理方式1)，一般还将苯、甲苯、环己烷、甲基环己烷等组分进行单独定量分析(处理方式2)，两个实际天然气样品按照数据处理方式2获得的结果见表2。

总体思路是推进公共服务领域的供给侧结构性改革，增强基本公共服务供给的均等化程度，增加非基本公共服务供给的多元化水平，更好地解决人民日益增长的美好生活需要与不平衡不充分发展之间的矛盾。结合本文的实证检验结论，对如何推进公共服务领域的供给侧结构性改革，提出以下政策建议：

In our study, we had 4 patients that had a recurrence of their symptoms (4.6%). A systematic review of the literature by Samaranayake[17] has demonstrated that across various studies with median follow-up ranging from 3 to 106 mo the recurrence rates varied from 0%-15.4%. Our Kaplan Meier analysis revealed a 2 year recurrence rate of 7%, which can be compared to other studies like McLean[5] who demonstrated a recurrence rate of 9.74% (95%CI: 6.1%#15.5%) at 2 years.

Pre-operative and post-operative Wexner score values for constipation and incontinence were inserted in tables. The median and interquartile range (IQR) values were calculated, and comparison and analysis between pre-operative and postoperative values were performed using the Wilcoxon signed rank test. Complication and recurrence rates were evaluated and analysed using the Kaplan-Meier method. Avalue < 0.05 was considered as significant. Libreoffice Calc 6.2.8 was used for the calculations (The Document Foundation).

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There was an overall improvement of the daily life activity for the majority of patients, which correlates with the results of other studies[4,17,18]. McLean[5]demonstrated patient satisfaction levels of 93% at 5 years, Consten[19] showed that both rates of faecal incontinence and obstructed defecation decreased significantly after LVR compared to the preoperative incidence.

CONCLUSION

对照组中出现不良事件患者共8例，不良事件发生率为18.18%；再住院患者为10例，再住院率为22.72%；观察组中出现不良事件患者共3例，不良事件发生率为6.82%，再住院患者2例，再住院率为4.55%。观察组患者的不良事件发生率及在住院率均低于对照组，差异有统计学意义（P＜0.05）。

Over the last few years there have been concerns about the usage of meshes in pelvic surgery, especially since serious complications have been recorded in urogynaecology procedures.

To show that the incidence of mesh-related complications, and particularly mesh erosion, after LVMRs is low, especially when a biological mesh is used. We also wanted to investigate whether there is a significant improvement in function and quality of life outcomes.

另一方面，阴离子表面活性剂溶于水能电离出Na+和阴离子基团，其中Na+能够通过煤中原生孔裂隙进入煤体，发生离子交换，置换出煤中Ca2+、 Mg2+，另外，煤表面虽然带负电荷，但由于煤表面存在着或多或少的缺陷，使得煤表面电荷分布不对称，仍存在正电荷，因此煤需要将溶液中电离出的阴离子基团吸附到没有被反离子所占的位点，以使煤表面能趋于稳定，吸附过程示意图如图7所示。从煤样的SEM图谱(图2)可以看出，原煤样结构较为均匀致密，而浸泡后的煤样矿物颗粒的连接处有明显的孔隙产生，表明煤体与有机/酸复合溶液之间不断进行着离子交换、颗粒运移等化学反应。

Questionnaires for the calculation of Wexner scores for constipation and incontinence were completed by 86 patients who underwent LVMR with Permacol (Biological)mesh from 2012 to 2018 at University Hospital Wishaw. The patients were followed up in the clinic 12 mo after surgery. Statistical analysis of the result included the calculation of median and interquartile range (IQR) values and comparison and analysis between pre-operative and post-operative values. Complication and recurrence rates were evaluated and analysed using the Kaplan-Meier method.

The median Wexner scores for constipation pre-operatively and post-operatively were 14.5 (IQR 10.5-18.5) and 3 (IQR: 1-6), respectively, while the median Wexner score for faecal incontinence was 11 (IQR: 7-15) and 2 (IQR: 0-5), respectively (0.01). There were 4 (4.6%) recurrences, 2 cases with erosion of a suture through the rectum and 1 patient that returned with diskitis. There were no mesh complications or mortalities.

从单个功率合成器仿真结果来看,这种新型的径向波导空间功率合成结构工作带宽能够覆盖22 GHz～27 GHz,电磁场沿轴心对称分布,24路输入端口,每路插入损耗均在(14±0.2)dB内,相位本一致,呈现了良好幅度及相位一致性;从背靠背功率分配/合成器仿真结果来看,电场结构规律分布,在22 GHz～27 GHz范围内,相位具有良好周期性变化规律,最大插入损耗约为0.25 dB,回波损耗小于15 dB,整体损耗较小,驻波特性优良。

In our results, it is demonstrated that LVMR using a biological mesh is both safe and effective for the treatment of rectal prolapse and that it fundamentally improves bowel symptoms of obstructive defecation and faecal incontinence in patients with internal rectal prolapse and symptomatic rectoceles.

Since we acknowledge that the direct follow-up period was short, we will continue our efforts to follow up our patients and formally assess their quality of life again in the near future.