Generalised peritonitis from strangulated small bowel obstruction secondary to mesh erosion: a rare long-term complication of laparoscopic mesh sacrohysteropexy

Abstract

A 77-year-old woman who underwent an uncomplicated laparoscopic mesh sacrohysteropexy (LMH) in 2009 for uterovaginal prolapse, presented with features of small bowel obstruction (SBO) 9 years later. She underwent laparotomy which revealed that the sacrohysteropexy mesh had eroded into the small bowel causing complete obstruction, complicated by ischaemia and perforation. Small bowel resection and primary anastomosis was performed, and the patient had an uneventful postoperative recovery. Although rare, cases of SBO occurring secondary to the use of a synthetic mesh in LMH have been reported. This is the first reported case of SBO directly attributable to erosion of mesh into the small bowel itself. Given the increasing frequency of women undergoing surgical management of pelvic organ prolapse which involves techniques using synthetic mesh, it is important to consent patients appropriately for such life-threatening risks and to focus on the development of surgical techniques and mesh materials to minimise such complications.

Background

Rare cases of small bowel obstruction (SBO)occurring secondary to the use of a synthetic mesh in sacrohysteropexy have been reported.^1–5 However, to our knowledge, we report the first case of small bowel volvulus directly attributable to the erosion of the mesh into the small bowel itself. Women are increasingly undergoing uterine-preserving operations that involve the use of synthetic mesh for the treatment of uterovaginal or pelvic organ prolapse (POP). Since this case report was originally written, significant concerns have been expressed following an investigation into the complications associated with vaginal mesh repairs for uterovaginal prolapse. Subsequently, a moratorium, on the use of vaginal mesh in the entire UK, was announced in July 2018 after the recommendations of the Independent Medicines and Medical Devices Safety Review were accepted by the U.K. Department of Health and Social Care and National Health Service (NHS) England. On 29 March 2019, NHS Improvement and NHS England issued a letter to all acute trusts to extend the moratorium on the use of vaginal mesh until a set of conditions had been met.⁶ This makes the case described here particularly topical and means it is important to consider complications associated with mesh repairs, and focus on the development of surgical techniques and mesh materials which minimise such complications.

Case presentation

A 77-year-old woman was admitted to the emergency department with a 7-day history of generalised abdominal distension, absolute constipation and vomiting. On presentation, she was haemodynamically stable. Her abdomen was distended with hyperactive bowel sounds. A reducible right inguinal hernia was present, with no signs of strangulation. Her medical history included hypertension, atrial fibrillation and a tissue mitral valve replacement in 2008, complicated by a mitral valve thrombus in 2015 for which she was started on warfarin therapy. Her surgical history included a left inguinal hernia repair and laparoscopic mesh sacrohysteropexy (LMH) using a polypropylene mesh for uterine prolapse in 2009. The LMH had been an uncomplicated laparoscopic procedure with no associated subtotal or full hysterectomy at the time. Peritonization, that is, closure of the peritoneum over the mesh, was not performed at the time of the initial surgery.

Investigations

Initial blood tests were in keeping with vomiting and dehydration, with an alkalosis (pH 7.48) and acute kidney injury. International normalised ratio was raised at 9, secondary to prolonged vomiting and poor nutrition. However, there was no evidence of bruising or bleeding.

An initial chest X-ray showed an aspiration pneumonia, in keeping with her delayed presentation to hospital despite prolonged vomiting. A plain abdominal X-ray showed multiple, mildly prominent, proximal-mid small bowel loops within the upper abdomen. She was kept nil by mouth, a nasogastric tube was inserted, and gastric contents were aspirated. Intravenous fluids and intravenous antibiotics were administered, and a urinary catheter was inserted to monitor the urine output. An abdominopelvic CT scan was performed urgently with no contrast due to her poor renal function. This showed numerous fluid-filled and dilated loops of proximal and mid small bowel up to 4 cm in diameter due to SBO (figure 1A), with a bowel transition point in close proximity to the sacrohysteropexy mesh (figure 1B).

Figure 1.

(A) Coronal abdominopelvic CT demonstrating multiple fluid-filled small bowel loops with wall thickening, consistent with ischaemia. (B) Sagittal abdominopelvic CT demonstrating the presence of tacs used to attach the mesh to the sacral promontory.

Treatment

The patient was taken to the theatre for emergency laparotomy immediately after resuscitation, within few hours of hospital admission, under the care of a consultant surgeon and a consultant anaesthetist. The laparotomy revealed erosion of the polypropylene mesh from the previous LMH into the small bowel which caused the small bowel to ‘kink’ with associated twisting of the bowel, resulting in total obstruction with complete collapse of the bowel distally. Proximal to the level of obstruction was the significantly distended and ischaemic small bowel, with perforations causing the contents to leak intraperitoneally. Crucially, no adhesions were noted between the bowel and the mesh. A section of 30 cm of the ischaemic small bowel was resected and a primary, side-to-side anastomosis was made. As much of the mesh as possible was excised from around the uterus and sacrum. The abdomen was irrigated, and a pelvic Robinson drain was inserted. Of additional note, the sacrosacrohysteropexy was functioning well still and there was no evidence of prolapse. Histological analysis of the resected small bowel showed evidence of extensive fibrosis, scarring and foreign body giant cell reaction around birefrengent foreign material on the serosal surface, secondary to mesh eroding into the small bowel itself. There was additional intense congestion and haemorrhage, in keeping with SBO with vascular compromise.

Outcome and follow-up

Postoperatively, the patient was transferred to the intensive care unit. A postoperative abdominopelvic CT with contrast was performed which demonstrated that the small bowel loops had decompressed with no obstruction and no anastomotic leak. The patient had an uneventful postoperative recovery and was eventually stepped down to the surgical ward from where she was discharged a few days later. She was followed up in the surgical outpatient’s clinic a few weeks later, where she was found to be in good health and was thankful for the care she received.

Discussion

POP is a prominent public health issue, with recent estimates suggesting that women have a 12.6% lifetime risk of undergoing surgery for prolapse.⁷ A variety of surgical approaches exist, one of which is the LMH. It aims to reinforce uterine support by suspending the uterus from the sacral promontory using a polypropylene mesh.¹ The procedure has become increasingly popular as it preserves the uterus. The laparoscopic approach has been favoured over the abdominal one due to its minimally invasive nature and reduced recovery time.

Current literature focusing on the safety of uterine suspension techniques using mesh (including LMH) to repair uterine prolapse reports life-threatening but well-recognised complications. It is important to note that the complication rates associated with the use of synthetic meshes in LMH are substantially lower than those associated with vaginal mesh implants. LMH was generally considered a safe surgical technique for treating uterine prolapse, with low complication rates. A decade-long case series of 507 women who underwent LMH found the main major complications were pulmonary embolus (0.4%), bladder injury (0.2%), haemorrhage (0.6%) and adhesions to mesh (0.6%).² In this same case series, only three patients developed colicky abdominal pain at 4–8 months postoperatively, secondary to bowel adhesions. Another retrospective cohort study of 159 women who underwent LMH between April 2010 and December 2014, included two patients who developed bowel obstruction within 16 days postoperatively.³ The first was due to umbilical port-site herniation and, the second, due to small bowel volvulus around the barbed suture used for peritoneal closure. In another multicentre, prospective parallel cohort study which looked at 74 women who underwent LMH, only one developed SBO; however, there was no mention of the mechanism.⁴

Barbed sutures are a popular choice in laparoscopic surgery because they reduce operative times as there is no need for tying a knot. In LMH they can be used to close the peritoneum to stop the entrapment of bowel by the mesh. However, there is little data on the use of barbed sutures and their safety/efficacy and there are rising concerns that they may be associated with adverse outcomes. A 2015 literature review found 13 cases of SBO following laparoscopic pelvic surgery using barbed sutures.⁵ Such complications have been shown specifically in LMH with a case report describing a female patient presenting on day-2 post LMH with SBO; diagnostic laparotomy revealed a volvulus where the mesentry was hooked by the end of the barbed suture.⁸

In our case there was no associated peritonization of the mesh during LMH, meaning that the peritoneum was not closed over the mesh. It is thought that peritonization can reduce the complications associated with mesh repair; however there is minimal evidence to support this and no direct comparison of associated complications between methods.⁹ Studies performed show that, generally, there is systematic use of peritonization during sacral colpopexy.⁹ It is important to consider whether variations in specific techniques used during LMH are associated with increased risk of SBO/mesh erosion, particularly, lack of peritonization and the use of barbed sutures. Further research is required to establish guidelines on the use of both these methods in LMH. Furthermore, further research on the use of different types of meshesis required. Studies have suggested that the use of a xenogenic or a biologic barrier, such as a collagen-coated biosynthetic mesh with interposition of collagen to act as a buffer/barrier between the synthetic mesh and tissue, can prevent mesh erosion into the surrounding tissues.^{10 11}

Synthetic meshes have come under great scrutiny in recent years, with campaigns against their use. Since this case report was originally written, an independent review (July 2018) of surgical mesh procedures chaired by Baroness Cumberlege recommended that there should be a pause in England on vaginally inserted mesh and tape to treat stress urinary incontinence and POP due to safety concerns. It has been recommended that a register of these operations be kept to ensure complications, particularly like the one we have reported here many years after the surgery, are recorded. This makes our reported case important in highlighting the potential for the mesh from LMH to directly erode into the bowel, leading to SBO; this is not previously (to our knowledge) documented in literature and has the potential to support future research and regulations on mesh repair.

Patient’s perspective.

I am very happy with all the care I have received since being in here but it is upsetting to think that this (small bowel obstruction secondary to laparoscopic mesh sacrohysteropexy) can happen, and I had no idea.

Learning points.

• Life-threatening small bowel obstruction can occur as a result of mesh erosion, even several years after laparoscopic mesh sacrohysteropexy.

• Patients should be adequately consented on the risks associated with the use of synthetic mesh pelvic organ prolapse surgeries.

• Publishing cases such as this will support research into the development of safe surgical techniques with novel mesh materials, which will establish their future in urogynaecological surgery.