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http://www.bioscience.org/2003/v8/b/989/pdf.pdfPAGE 1:[Frontiers in Bioscience 8, b1-5, January 1, 2003]1COLONIC PACING IN THE TREATMENT OF PATIENTS WITH IRRITABLE BOWEL SYNDROME:TECHNIQUE AND RESULTSAhmed Shafik 1, Olfat El-Sibai 2, Ali A. Shafik 3, Ismail Ahmed 31 Professor and Chairman, Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Cairo,2 Professor and Chairman, Department of Surgery, Faculty of Medicine, Menoufia University, Shebin El-Kom, 3Lecturer inSurgery, Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Cairo, EgyptTABLE OF CONTENTS1. Abstract2. Introduction3. Material and methods3.1. Subjects3.2. Methods3.2.1. Pacemaker application3.2.2. Determination of the myoelectric activity: basal and during pacing3.2.3. Home pacing4. Results and Discussion4.1. Effect of colonic pacing on the clinical manifestations of the IBS5. Acknowledgment6. References1. ABSTRACTThe treatment of the irritable bowel syndrome(IBS) is not entirely satisfactory as the exact cause of thecondition has not been revealed. We have demonstrated ina recent study that the IBS exhibited a “tachyarrhythmic”electromyographic pattern; the wave rhythm was irregularand wave variables were higher than those of the healthyvolunteers. We suggested that a disorder of the colonicpacemaker discharges these abnormal waves therebycausing the motor disorders of IBS. In another study, wedetermined the colonic pacing parameters needed tomodulate the disordered pacemaker. In the currentcommunication we investigated the effect of colonicpacing, using these parameters, on the EMG activity of thesigmoid colon (SC) and on the clinical manifestations ofpatients with IBS. A pacemaker was implanted in asubcutaneous pocket in the inguinal area and its two leadswere hooked to the colosigmoid junction. The effect ofcolonic pacing on the SC EMG activity was investigated byinserting two recording electrodes into the SC muscle. Thepatients were then trained for home pacing after removal ofthe 2 recording electrodes. Nine patients (age 42.7±4.2years, 6 women) with IBS were studied. The pre-pacingtachyarrhythmic pattern of EMG was recorded. On colonicpacing, the slow wave rhythm became regular and wavevariables were normalized; the symptoms of the IBSimproved. The optimal parameters used for pacingcomprised an amplitude of 6 mA, a pulse width of 150 msand a frequency of 25% higher than that of the basalcolonic waves. In 7/9 patients the improvement ofsymptoms continued when pacing was ceased after 6months of daily pacing; the pacemaker was removed after 3months of non-pacing. In 2/9 patients, pacing needed to becontinued because the symptoms recurred each time thepacing was ceased. In conclusion, colonic pacingsucceeded in normalizing the tachyarrhythmic pattern andrelieving the symptoms of the IBS. No complications wereencountered and the method was well accepted andtolerated. Further studies on a large group of patients arerequired.2. INTRODUCTIONIrritable bowel syndrome (IBS) is not anuncommon disease. The patients complain of abdominalpain with or without alterations in bowel habits but do notshow any anatomical abnormality on diagnostic testing (1-5). There is a wide variety of complaints; more than 90% ofthe patients present with 2 or more of the following: feelingof abdominal distension, increased frequency of bowelmovements with the onset of abdominal pain, loose stoolswith onset of pain, and relief of pain with defecation (6).The most typical complaint is a crampy diffuse abdominalpain which is associated with alternating constipation anddiarrhea or postprandial urgency (1).The etiology of IBS is hitherto unkown (1-6). Ithas been related to disorders of motility or perception of thelower gut (2-7). Other factors as behavioral, psychological

 

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PAGE 2:WE HAVE POSSIBLY A DISORDER OF THE SIGMOID:Colonic pacing2Figure 1.Incision along the middle one-third of, and 2 cmabove, the inguinal ligament.or mucous membrane disorders and food intolerance maybe also involved in some cases (8-11).We recently studied the electromyographicactivity of IBS (unpublished data). It showed a“tachyarrhythmic pattern”; the frequency, amplitude andconduction velocity of the slow waves were significantlyhigher than in the healthy volunteers and the rhythm wasirregular. Fast activity spikes or action potentials (APs)followed or were superimposed on the slow waves (SWs);they were inconsistent and occurred randomly. The sigmoidcolon pressure was significantly higher in IBS patients ifcompared to that of the healthy volunteers (6,7, andunpublished data). Action potentials were coupled withbouts of pressure increase which was significantly higherthan that recorded in the normal controls. The studysuggested that the cause of the IBS is related to an aberrantfocus in one or more of the colonic pacemakers. Colonicelectric activity seems to regulate the colonic motilitywhich is presumably impaired by a disorder affecting theelectric waves (12,13). This was evident from theelectrosigmoidograms of the various pathologic lesions ofthe SC in which the electric waves with low variables(frequency, amplitude and conduction velocity) wereassociated with diminished colonic motility (13).Further studies have demonstrated that the colonpossesses at least 4 pacemakers which generate the electricactivity to the colon (14). They are located at the cecalpole, the cecocolonic junction, the mid-transverse colonand at the colosigmoid junction (CSJ).The treatment of patients with IBS is problematicand the results are in most cases unsatisfactory (1-5).Actually, there is so far no curative treatment available forIBS. The tachyarrhythmic pattern of the EMG activity ofthe SC seems to be responsible for the disordered motileactivity in the IBS, the associated abdominal pain and thebowel irregularities (unpublished data). Electric waves ofthe SC have been demonstrated to start at the CSJ and tospread caudad along the SC; a CSJ pacemaker is thoughtto initiate and regulate the SC electric and motor activity(12-14). In a recent study (unpublished data), we havedefined the colonic pacing parameters that are required tomodulate the “tachyarrhythmic” pattern of the SC; colonicpacing using these parameters has normalized thetachyarrhythmic waves.In the current communication we studied the effect ofcolonic pacing on the EMG activity of the SC and on theclinical manifestations of patients with IBS.3. MATERIAL and METHODS3.1. SubjectsThe study comprised nine patients with IBS whogave an informed consent before enrolment in the study.The mean age was 42.7±4.2 SD years (range 35-54); 6were women and 3 men. They complained of diffuseabdominal pain which was relieved by defecation. Allpatients had loose stools and a feeling of abdominaldistension or bloating, and 4/9 had in addition the feelingof incomplete evacuation with urgency. The mean durationof the symptoms was 10.6± 4.8 SD years (range 6-14). Thepatients had followed various medical regimens for longperiods with temporary improvement.Physical examination including neurologicassessment was unremarkable. Laboratory work as well asproctoscopy, colonoscopy and barium enema studies werenormal.3.2. Methods3.2.1. Pacemaker applicationAfter the patients had fasted for 12 hours, thecolon was emptied by means of saline enema. Thepacemaker (Prevail, Medtronic, Minneapolis, Minn., USA)was implanted in a subcutaneous pocket in the inguinalarea. Two leads were jointly passed subcutaneously fromthis area to the anal orifice and then through the anal canal,rectum and SC to be hooked to the CSJ. Under generalanesthesia, a 4-cm incision was performed 2 cm above andparallel to the mid one third of the inguinal ligament(Figure 1). We dissected in the subcutaneous space to shapea pocket for the pacemaker. A tunnel was then created bymeans of a dissecting forceps that was passedsubcutaneously from the pocket alongside the scrotum orlabium majus to the anal orifice where a 1-cm incision wasperformed in the painless anal mucosa 5 cm orally to theanal orifice. A long artery forceps was advancedsubcutaneously through the incision until it appeared in thepocket. The tips of the leads were grasped with the forcepsand pulled through the tunnel to emerge from the analincision. The leads, now in the gut lumen, were thendirected orally under sigmoidoscopic and fluoroscopiccontrol until they reached the CSJ where they were hooked;they lay on the mucosal surface of the gut. The patient leftthe hospital 24 hours after surgery. An analgesic was givenon the first post-operative day and a quinolene antibioticfor two days.3.2.2. Determination of the myoelectric activity: basaland during pacingThis experiment was done to test the effect ofcolonic pacing on the EMG activity of the SC. The patientswere allowed 7-10 days to recover from surgery. Afterfasting for 12 hours, the colon was evacuated by salineenemas. The SC EMG was recorded by 2 electrodes similarto that described above. They were introduced per anum

 

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YEP Screamer but regarding Enterra(gastric pacing) it does NOT improve emptying.It dosen't seems to be the case with the Shafik study.He's able to provide motility.