Joop Konsten

Long-term follow-up of dynamic graciloplasty for fecal incontinence

AbstractPURPOSE: Graciloplasty has been used as a treatment for end-stage fecal incontinence since 1946. Electric stimulation with an implantable pulse generator has existed for 15 years. The gracilis muscle is wrapped around the anal canal and stimulated by intramuscular electrodes connected with an implantable pulse generator. Initial reports have been promising, but long-term results have not been presented to date. METHODS: Data of 200 consecutive patients with a follow-up of at least two years were analyzed in a prospective manner from 1986 until 1999. RESULTS: The overall success rate was 72 percent. In patients with fecal incontinence caused by trauma, the rate was 82 percent. Once continent, patients remained continent after a median follow-up of 261 (standard deviation, 132) weeks. Median survival of the implantable pulse generator until battery expiration was 405 weeks. Disturbed evacuation remained a problem in 16 percent of all patients. Complications were frequent but treatable. CONCLUSION: Dynamic graciloplasty is a good, cost-effective treatment for fecal incontinence with results lasting for a median of more than five years.

Morphology of dynamic graciloplasty compared with the anal sphincter.

Dynamic graciloplasty for fecal incontinence includes gracilis muscle transposition around the anal canal as a new sphincter and subsequent electrical stimulation. The aim of electrical stimulation is to transform the gracilis fast-twitch, “fatigue-prone” fibers into slow-twitch, “fatigue-resistant” fibers to achieve a sustained tonic contraction. The latter is considered essential for sphincter function. Therefore, the following features of transposed gracilis muscle morphology were studied in nine patients before and after electrical stimulation: 1) the percentage of Type I fibers, 2) the lesser diameter of these fibers, and 3) the positive collagen staining area. Furthermore, the external anal sphincter and gracilis muscle histology was investigated in six autopsy cases. The mean percentage of Type I, slow-twitch, fatigue-resistant fibers in transposed gracilis muscle increased from 46 percent before electrical stimulation to 64 percent (P<0.01, paired Studentst-test) after electrical stimulation. The mean lesser diameter of these fibers did not change significantly (from 32 to 29 μm), and the mean percentage of collagen increased from 4 percent before electrical stimulation to 7 percent (P<0.01) afterward. The external sphincter in cadavers demonstrated a predominance of Type I fibers (80 percent) with a lesser diameter of 23μm and a high percentage (12 percent) of collagen. Gracilis muscle histology was uniform at six different sample sites in these cadaver dissections. We conclude that electrical stimulation induces histologic changes in transposed gracilis muscle, allowing this muscle to function as an external anal sphincter.

Mri After Chemoradiotherapy of Rectal Cancer: A Useful Tool to Select Patients for Local Excision

PURPOSE: If identification of good responders to neoadjuvant chemoradiotherapy in rectal cancer is possible, there might be opportunities for local excision in selected patients. The aim of this study was to determine whether postchemoradiation MRI in rectal cancer can accurately identify ypT0 to 2/ypN0, because both features are essential for identification of good responders. METHODS: Seventy-nine patients (4 hospitals) underwent postchemoradiation MRI, 62 received a lymph node-specific contrast agent (ultrasmall superparamagnetic iron oxide). An expert and general radiologist prospectively predicted whether the tumor penetrated the mesorectal fat and whether nodes were sterilized after chemoradiation. Histology was the reference standard. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: For prediction of whether a tumor penetrated the bowel wall, there was an negative predictive value of 0.90 and 0.76 for the expert and general radiologist, respectively. The negative predictive value for prediction of nodal status was 0.95 and 0.85 for expert and general radiologist, respectively. CONCLUSION: This prospective multicenter study demonstrates that MRI with a lymph node-specific contrast agent interpreted by an expert radiologist can select ypT0 to 2/ypN0 rectal cancer with low risk of undetected nodal metastases or invasion through the bowel wall. These patients could thus have been selected for local excision. However, future studies will have to prove equal outcome of such a modified surgical approach compared with current practice.

Dynamic graciloplasty for anal atresia

The aim of this study was to assess whether an electrically stimulated graciloplasty (dynamic graciloplasty) can achieve continence in nine patients with anal atresia (median age, 28 years; range, 18 to 40). As the first procedure, a gracilis muscle was transposed. Six weeks later, intramuscular electrodes were implanted and connected to a pulse generator. Eventually, the muscle was gradually trained, by electrical stimulation, to achieve fecal continence. Continence was obtained in five patients (55%). Manometry demonstrated an increase in mean anal pressure, from 36 mm Hg (without stimulation) to 52 mm Hg (with stimulation), after 8 weeks (mean increase, 16 mm Hg, [95% confidence interval, 8, 24 mm Hg; n = 9; P < .01). Failures resulted from a noncontracting distal part of the gracilis muscle (in three patients) and a nondistending rectum (in one patient). We conclude that dynamic graciloplasty can achieve continence in a substantial number of patients with thus-far untreatable incontinence after surgical correction for anal atresia.

Feasibility of stoma continence, using electrically stimulated rectus abdominis muscle in pigs.

To develop surgical techniques to obtain stoma continence with a muscular sphincter, the anatomy (especially innervation and vascularization patterns) of the human abdominal wall muscles was studied in three cadaver dissections. It was found that transposed rectus abdominis muscle might be positioned as a new sphincter (sphincteroplasty). Next, the feasibility was assessed in six pigs, and the rectus muscle was positioned as a sphincter around a Thiry Vella loop. The use of three different surgical procedures has been assessed: 1) a muscular ring of the proximal rectus was constructed and partly denervated the muscle; 2) the distal end of the Thiry Vella loop was pulled through the middle of the rectus muscle, thereby also introducing partial muscle denervation; and 3) a sling was constructed using the distal muscle part. In four of these six pigs, identical procedures were performed also at the left side. These new sphincters were electrically stimulated (with implanted stimulation devices) to study the feasibility of prolonged sphincter contraction independent of will. Stimulation with a frequency of 25 Hz was used at the right and 2 Hz was used at the left sphincters. It was found that electrical stimulation with a frequency of 25 Hz as well as 2 Hz increased the percentage of Type I (relatively fatigue-resistant) muscle fibers significantly from 42 to 65 percent (n = 6) in the right and from 50 to 67 percent (n = 4) in the left rectus muscle into innervated muscle areas of the sphincters. This increase is considered essential for sustained sphincter function. Stoma continence was not achieved because constructing muscular rings (as a sphincter) caused partial atrophy. Construction of a sling using the distal part of the rectus did not cause substantial atrophy, but continence was not achieved because the dorsal side of the Thiry Vella loop was not completely covered with muscle fibers.

Defecographic evaluation of dynamic graciloplasty for fecal incontinence

PURPOSE: A prospective defecographic study was performed to evaluate the anorectal physiology of dynamic graciloplasty (gracilis muscle transposition and subsequent implantation of an electric stimulator) for treatment of fecal incontinence. METHODS: From November 1986 until May 1993, 38 consecutive patients with incapacitating fecal incontinence were treated with “anal dynamic graciloplasty.” Defecography was performed before and after surgical procedures. Defecographic data (anorectal angle, perineal descent, anal canal length, anal canal width, and anal leakage) were correlated with respect to clinical outcome and anal manometry. RESULTS: Fecal continence was achieved in 24 patients, which correlated significantly with no leakage of barium contrast during defecography (P<0.01, Kruskal-Wallis one-way analysis of variance). In addition, minimum anal canal width decreased from 7 mm before surgery to 1 mm after dynamic graciloplasty (P<0.01, paired Studentst-test). CONCLUSION: Defecography is an efficient method to evaluate dynamic graciloplasty for fecal incontinence.

Dynamic myoplasty in growing dogs as a feasibility study for treatment of fecal incontinence

The feasibility of skeletal muscle transposition and electrical stimulation (dynamic myoplasty) for treatment of fecal incontinence has been shown in adults. It might be attractive to use such a technique in pediatric patients. Therefore, the influence of growth on skeletal muscle transposition and stimulation was studied in five puppies. In each dog, two neosphincters were constructed around a Thiry-Vella loop by using a dissected sartorius muscle with the neurovascular supply intact. In each of these five puppies, one of these muscles was electrically stimulated during a mean of 19 weeks (one puppy died during the first postoperative week). Muscle biopsies showed an increase in the percentage type I, fatigue-resistant muscle fibers from 61 to 94 in electrically stimulated sartorius neosphincters, but also an increase from 57 to 67 percent in transposed nonstimulated sartorius muscles. The diameter of these type I fibers during growth increased 36% in eletrically stimulated sartorius neosphincters and 55% in nonstimulated sphincters. Function of the neosphincters was tested with the inflow of saline in the Thiry-Vella loop. It was shown that the stimulated neosphincters were capable of inhibiting flow (which corresponded to manometric pressure registrations), but the nonstimulated sphincters were unable to inhibit flow. The experiments were complicated by infection and necrosis around the implanted stimulators in four puppies (which required reimplantation). We conclude that a dynamic myoplasty for fecal incontinence is feasible in growing puppies but that the technique is unacceptable during rapid growth because of the risks of infection and dislocation of the implanted device.

Dynamic graciloplasty for restoration of continence after traumatic destruction of the rectum and sphincters: report of a case.

A thirteen-year-old girl was run down by a speedboat, which resulted in traumatic destruction of the rectum and anal sphincters. She was treated by using a modified Duhamel procedure for rectal reconstruction and a double gracilis muscle transposition as the sphincter replacement procedure. Eight weeks after the first operation, intramuscular electrodes were implanted in both gracilis muscles and connected with an implanted electrical stimulator. This electrically stimulated gracilis muscle neosphincter restored sphincter function while anorectal sensation was preserved as a result of an intact rectovaginal septum. After closure of the temporary colostomy, the patient has good continence.

Demonstration of the Feasibility of Implantation of a Skeletal Muscle Pulse Generator for Fecal Incontinence in a Patient with an Implanted Unipolar DDD Pacemaker

KONSTEN, J., et al.: Demonstration of the Feasibility of Implantation of a Skeletal Muscle Pulse Genera‐tor for Fecal Incontinence in a Patient with an Implanted Unipolar DDD Pacemaker. Electromagnetic fields and myopotentials from skeletal muscle may interfere with the function of a cardiac pacemaker. A 65‐year‐old woman with a unipolar DDD cardiac pacemaker underwent dynamic graciloplasty (trans‐position of the gracilis muscle around the anal canal and subsequent implantation of a bipolar pulse generator to stimulate the gracilis muscle), for the treatment of fecal incontinence. This gracilis pulse generator is turned “off” with an external magnet to allow defecation. Appropriate functioning of these two pulse generators (the cardiac pacemaker and the gracilis pulse generator) was tested during implantation of the gracilis pulse generator and afterwards. It was demonstrated that the combination could be used safely in this patient.

Constipation after dynamic graciloplasty

To the Edi tor--We read with interest the article by Korsgen et al. (Dis Colon Rectum 1995;38:1331-1333) regarding constipation after dynamic graciloplasty and would like to make some comments. Constipation and incontinence are indeed two items that are closely related. Many patients are incontinent for feces after periods of severe evacuation problems. In treating the incontinence problem, the evacuation problem can emerge again. This switch is not, in particular, related to the dynamic graciloplasty but is known in all surgical procedures for incontinence. The evacuation problem can be worsened, however, when, during graciloplasty, the muscle is ~ransposed around tl~e anal canal under high tension. In dynamic graciloplasty, closure of the anal canal depends on contraction of the muscle and not on tightness of the loop. Resting pressures exceeding 100 c m H20 , as described in this article, might indicate a loop that is too tight. Recently, we published our experiences in dynamic graciloplasty and found much lower resting pressures.1 Defecography showed adequate opening of the anal canal at rest. 2 We encountered constipation in 18 percent of our patients; reasons were a lumpy, bag-shaped rectum or poor straining techniques. If treatment was necessary at all, patients could be treated by conservative methods (suppositories, enemas, or biofeedback). Conversion to a permanent colostomy had to be performed in only one patient with severe constipation (who was incontinent because of a congenital disorder). We agree with Korsgen et al. that dynamic graciloplasty should be reserved for a carefully selected group of patients. We consider dynamic graciloplasty to be a safe and good procedure, provided muscle transposition is not too tight.