Keywords

1 Introduction

Fecal incontinence (FI) is a debilitating condition that affects up to 18% of the general population and up to 55% of the elderly [1], and causes frequent hospitalization in nursing homes, worsening the quality of life (QoL) of those affected. Although treatment is difficult and the success rate is often not high, simply attempting to correct it can significantly improve the patients’ QoL [2, 3]. The actual effectiveness of the surgical treatment of FI remains difficult to assess: most studies are retrospective and include only a limited number of patients, the data collection methods are not standardized, and no FI severity score has been universally accepted [4]. Several treatment options have been proposed over the last twenty years, but none of them can be considered the gold standard. The first step in a patient with FI is to rule out organic pathology (e.g., neoplasm); treatment involves the use of medications that reduce bowel motility, correction of the diet, and pelvic floor re-education. These three elements provide a solid basis for the initial treatment of FI, achieving some improvement in symptoms in almost half of the cases, without the need for further investigations or invasive procedures [5]. If medical nutritional therapy is insufficient to ensure improvement in the patient’s QoL, surgical therapy must be considered. The patient being considered for surgical intervention must first be adequately examined by performing clinical-instrumental tests such as anorectal manometry, endoanal and pelviperineal ultrasound, dynamic defecography (or MRI defecography), and electrophysiological tests such as electromyography and pudendal nerve terminal motor latency [6].

This chapter presents the main surgical options that can be used in patients with FI.

2 Dynamic Myoplasty

Pickrell et al. [7] first described the use of transposition of the gracilis as a neosphincter in 1952. The first electrically stimulated graciloplasty was reported in 1968 [8], but the concept of converting fast fibers to slow fibers using an electrical stimulator was not proposed until 1991 by Baeten et al. [9] and Williams et al. [10]. Electrically stimulated graciloplasty (dynamic graciloplasty) was developed in an effort to improve the functional results of simple transposition of the gracilis. The major limitations of unstimulated graciloplasty included the inability of patients to contract the transposed muscle voluntarily and the physiological inability of the muscle to sustain a tonic contraction over a prolonged period of time.

2.1 Technique

The patient is positioned in the lithotomy position with the thighs flexed, to expose the perineal region; intraoperative curarization is not required. Surgery begins with incision and mobilization of the gracilis muscle. The surgeon makes an incision on the medial inner aspect of the thigh, a few centimeters below the origin of the thigh, up to 10 cm before the knee. Mobilization of the gracilis muscle must start from its central part to preserve the main neurovascular pedicle. The left index finger placed under the gracilis pulls the muscle out, allowing dissection of the nearby connective tissue and coagulation of additional secondary vascular pedicles. The middle finger of the surgeon’s left hand penetrates the distal tendon to the pes anserinus (at the level of the internal tibial tuberosity), where a small incision is made. The distal gracilis tendon must be interrupted at this level. The muscle is then tipped over on the perineum, and it is important to avoid twisting or compressing its neurovascular pedicle. At this point, the perineorectal area must be prepared by making two lateral incisions of 4–5 cm each between the anal verge and ischium. To delineate the perineorectal area, a tunnel must be create between the origin of the thigh and the ipsilateral perineal incision. This tunnel must be large enough to allow the muscle to be laid without tension or obstruction, and special care must be taken to not twist the muscle. The gracilis muscle is rotated and passed through the perineorectal area to completely encircle the anal canal. It is important to avoid any contact between the muscle and the anal canal (because of the risk of ulceration) or excessive muscle tension (it must be possible to pass two fingers between the anal canal and the muscle). After checking for correct muscle tension, the distal tendon is fixed to the contralateral (gamma-shaped loop) or ipsilateral (alpha-shaped loop) ischium with an orthopedic tendon clamp. During fixation, the thigh must be positioned in full adduction to achieve adequate tightening and avoid secondary loosening. After hemostasis, the perineal incisions are closed without placing a drain. At this point, two neurostimulation electrodes are positioned and inserted into the muscle, with the anode placed in the distal portion and the cathode in the proximal one. The electrodes are fixed with nonabsorbable 4/0 Prolene sutures. Positioning of the electrodes connected to the external stimulator allows determination of the stimulation threshold and the maximum stimulation value. Placement of the neuromuscular pacemaker requires an incision in the ipsilateral iliac fossa of the harvested muscle to provide subcutaneous access from the origin of the thigh to the anterior abdominal wall. Sheathed electrodes are then passed through this subcutaneous pathway to the rectus sheath and connected to the neuromuscular pacemaker. The pacemaker is placed in the subcutaneous space and secured to the fascia with a nonabsorbable suture. The procedure ends with closure of the thigh and cessation of electrical stimulation. A Redon suction drain is inserted into the thigh and drained through the tibial incision. After hemostasis, the subcutaneous tissue and muscular perimysium are approximated by a continuous suture layer of slowly absorbable material. The cutaneous plane is closed with a continuous non-absorbable suture. The stimulator is synchronized by telemetry with the stimulation parameters determined during electrode placement [11].

2.2 Results

Wexner et al. [12] reported the results of a multicenter study of 115 patients who underwent stimulated graciloplasty between 1993 and 1999. Overall success, defined as a 50% reduction in the frequency of incontinence episodes, was achieved at 1 year in 62% of patients, none of whom had a stoma at the time of graciloplasty. These results were confirmed at 18 and 24 months in 55% and 56% of patients, respectively; 15% of patients in this group reported complete continence; 42% had continence levels of 50% to 99%. The success rate for patients who had a stoma at the time of graciloplasty was 37.5% at 1 year. This result improved significantly to 62% at 18-month follow-up. Significant improvements were also noted in QoL. A systematic review of the literature on dynamic graciloplasty [13] showed that the procedure is associated with a non-negligible morbidity, on average 1.12 events per patient (range, 0.14 to 2.08). These data suggest that either all patients had at least one complication or that some patients experienced multiple complications such as infection (28% of the cases), stimulator or electrode malfunction (15%), and leg pain (13%). Other complications, with a frequency greater than 5%, were constipation or obstructed defecation, anal pain, rectal or gracilis injury, and pacemaker battery depletion. The efficacy of the procedure, as measured by the satisfaction rate with continence, ranged from 42% to 85%. Reasons for stimulator explantation, ranging from 0.14 to 1.07 per patient, included erosion of the anal canal by the gracilis muscle, rectal perforation from use of enemas, rejection of the electrodes or stimulator, constipation, migration of the electrodes, detachment of the gracilis tendon from the ischium, battery malfunction, perianal abscess, pain, fistula, or perineal hernia. Dynamic graciloplasty continues to be performed in Europe and Canada, but the hardware for the procedure is not yet approved in the United States. Currently, its use is largely limited to a small number of centers where sufficient patient volume and surgical experience ensure low morbidity and satisfactory functional outcomes.

3 Artificial Bowel Sphincter

The first implantation of an artificial bowel sphincter (ABS) for FI was reported in 1987 [14]. Currently, there are two types of ABS: the one originally developed to replace the urinary sphincter but then used in patients with anal incontinence (Acticon neosphincter, American Medical Systems, Mn, USA) [15] and the newer magnetic anal sphincter (Fenix, Medical Thorax, Mn, USA) [16].

3.1 Acticon Neosphincter

The Acticon ABS is a fully implantable prosthesis made of a silicone elastomer. It consists of a perianal sphincter ring (cuff), a regulatory reservoir (balloon), and a control pump.

The ring is implanted in the upper anal canal. The three elements are connected by a kink-resistant tube. The pressure-regulating reservoir, which controls the pressure exerted on the anal canal by the closure ring, is implanted in the subperitoneal space of Retzius, lateral to the bladder. The control pump is implanted in the scrotum in males and in the labia majora in females and contains a resistor and a deactivation button in its upper part. The lower part of the pump consists of a piston that the patient squeezes to deliver the fluid inside the implant [15, 17]. The ABS works semiautomatically [15]. The sphincter muscle automatically provides constant anal closure at low pressure approaching physiological levels; the pressure is transmitted to the closure cuff by the pressure-regulating pump. Emptying is actively controlled by the patient: the anus is opened by transferring the fluid from the cuff to the pressure-regulating reservoir. Transfer is achieved by pressing the piston of the regulating pump five to ten times. Reclosure of the anus occurs automatically within minutes by gradually restoring the baseline pressure in the cuff.

3.1.1 Technique

The incision may be made perianally or laterally [17, 18], then a tunnel is created around the upper anal canal, about 5 cm deep, and dissected with the fingers. A long-curved forceps is then inserted along the dissection path around the anal canal to guide a tape (sizer) needed to determine the length of the occlusive cuff to be implanted.

The cuff is closed around the anal canal by passing the tubing through a slit at its end. Once the sphincter cuff is closed, a digital rectal examination can confirm the occlusive effect of the device.

A small suprapubic horizontal abdominal incision is made to create a space lateral to the bladder in the subperitoneal space of Retzius to accommodate the pressure-regulating balloon. The sphincter cuff tube is passed subcutaneously from the perineal incision to the abdominal incision.

The sphincter cuff is then inflated, the empty pressure-regulating balloon is implanted at its subperitoneal site and pressurized with 40 mL of radiopaque isotonic fluid. A Hegar dilator is then used to create a subcutaneous tunnel from the abdominal incision to the scrotum or labia, into which the control pump is inserted.

3.1.2 Results

ABS has shown significant and consistent improvement in the continence of patients. However, in two recent prospective studies [19, 20] surgical revision was required in approximately 50% of patients and explantation of the device was required in 25–35%, but 85% of patients who had a properly functioning ABS were satisfied with the device and its operation [19]. Wong et al. [20] reported a six-year success rate of 67% with satisfactory functional outcomes and QoL. The experience of Darnis et al. [21] was instead less positive: at least one complication occurred in all included patients. Skin infection or ulceration was reported in 76% of patients, perineal pain in 29%, rectal voiding dysfunction in 38% and ABS explantation in 81%. Compared to sacral neurostimulation, Acticon ABS appears to offer better continence outcomes [22]. However, due to a higher incidence of terminal constipation after implantation and the greater invasiveness of the technique, it is suggested as a second-line procedure. It should be noted that the use of this device has recently been limited by the failure of health authorities to extend reimbursement for this device. Currently, the decision to implant an ABS requires prior case-by-case approval by health authorities, limiting the use of Acticon to a few specialized centers [6].

3.2 Fenix Neosphincter

The Fenix magnetic ABS is inspired by the Lynx anti-reflux device recently developed to treat gastroesophageal reflux. The device consists of a series of titanium beads with hermetically sealed neodymium-iron-boron (NdFeB) magnetic cores. The beads are connected by independent titanium threads to form a flexible ring that wraps around the external anal sphincter. The device is manufactured in different lengths depending on the number of beads (14 to 20) needed to accommodate variations in the circumference of the anal canal. A sizing device, very similar to the final device, is used to determine the appropriate configuration. The separation force required to open the adjacent beads is approximately equivalent to 100 g and was chosen based on animal studies and literature data on voiding forces in healthy individuals and individuals with defecation disorders [16, 23]. During defecation, the patient simply strains as in normal defecation. The force generated by the straining determines the number of beads required to facilitate the passage of stool through the device. The device was designed with an excessive diametric capacity and therefore does not restrict defecation or cause excessive strain [16].

3.2.1 Technique

The device is usually implanted under general anesthesia. A single incision is made at the perineal body, carefully cutting the anterior anorectal vaginal septum to a depth of approximately 3–5 cm proximal to the anal verge. A measuring instrument is then inserted to accurately measure the circumference of the anorectal junction. After correct sizing under fluoroscopic control, the measuring tool is removed and the device is selected and implanted according to the number of beads required to encircle the anal canal [16].

3.2.2 Results

The Fenix magnetic ABS shows promising early results. The passive reinforcement of the anal canal by the magnetic “cuff” accounts for the originality and simplicity of this technique. The patient does not have to do anything, other than reproduce the effort of straining to empty the rectum [23]. Lehur et al. [16] reported surgical site infections in 21.4% of cases, requiring device removal in 14.3%. After a median follow-up of six months, 21.4% of patients no longer had the magnetic sphincter in place. Compared with conventional ABS, the duration of surgery and hospital stay were significantly shorter with the magnetic ABS [24]. Short-term functional outcomes were similar for both sphincters in terms of revision and withdrawal rates. Although these results are encouraging, the use of the magnetic sphincter is currently limited to a few centers, where its efficacy is still under investigation [23].

4 Antegrade Colonic Enemas

The antegrade colonic enema (ACE) was first described by Malone et al. [25] in 1990 for the treatment of FI in children. It involves the creation of a continent stoma according to the Mitrofanoff principle [26]. The original procedure involved resection of the appendix and its cuff, while preserving the appendicular artery. A submucosal tunnel was then created, to which the distal end of the appendix was sutured. The appendix was then passed out of the right side of the lower abdominal wall as a stoma. Later, several modifications of this technique were described that used the terminal ileum [27], the cecum, the left colon, or the stomach [28]. In each case, a Foley catheter is placed in the stoma and left in place for 15 days until the antegrade enemas begin. This involves introducing water and/or enema solution antegrade into the colon and emptying the colon of stool, to relieve both constipation and incontinence [29].

4.1 Results

Very few studies have described the results. Chéreau et al. [29] analyzed 75 patients who underwent ACE and observed early complications in 5.3% and late complications (after 3 months) in 16% of patients. The early complications were iatrogenic perforation of the small bowel, ileus, and postoperative pelvic abscess. The main late complication was stoma stenosis, with an incidence that varied from 8% to 50% [29, 30].

At a median follow-up of 48 months, treatment was considered successful in 86% of patients. Both the Wexner score for FI and the QoL score improved in all patients.

5 Colostomy

Colostomy may sometimes be considered as a first-line measure in FI, but traditionally it has been considered as a last therapeutic resort in patients in whom other treatments have failed [31]. Despite its curative potential, colostomy impacts on QoL, particularly because of altered body image and constant feeling of being sick [32]. However, in one study conducted on patients who underwent colostomy, acceptable social function was reported to be associated with higher QoL scores than patients with FI [33]. Norton et al. [34] reported that 84% of patients with a colostomy for FI would choose to have it again. The mortality rate after colostomy is approximately 2% [13], and complications mainly include bleeding and parastomal hernia [35]. Long-term complications include skin rashes, leaks, and edema, but these are mainly due to inadequate management of the ostomy pouching system [36]. In most cases, a sigmoid colostomy is performed, which has the advantage of being easy to perform. The stoma created with the sigmoid colon is indeed easier to manage with stoma devices due to the presence of formed stool. Nowadays, the recent improvements in stoma devices guarantee a better QoL and allow almost normal physical, social and sports activities [6]. As for the correct management of the rectosigmoid segment downstream from the stoma, this is still debated in the literature, with no clear opinions [31].