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Mitrofanoff channel survival after pedicle ligation
CASE REPORT
MITROFANOFF CHANNEL SURVIVAL AFTER PEDICLE LIGATION P. D. METCALFE, M. P. CAIN,
AND
R. C. RINK
ABSTRACT In patients who have undergone complex genitourinary reconstruction, additional abdominal surgery is often required. We report 2 cases in which the blood supply to an existing Mitrofanoff channel was divided. In both cases, the conduits appeared to remain well perfused, presumably based on collateral blood supply. Both conduits remained healthy and functioning at more than 1 year of follow-up. UROLOGY 66: 657.e11–657.e12, 2005. © 2005 Elsevier Inc.
T
he pediatric patient who undergoes lower urinary tract reconstruction often requires a continent cutaneous channel to the bladder or cecum, or both. The complex nature of both the reconstruction and the patient may necessitate additional intraabdominal surgery. The subsequent surgery can be very challenging because of the reconfigured anatomy and adhesions. Although experimental evidence has shown that an enterocystoplasty segment can survive after delayed ligation,1 no cases of the viability of Mitrofanoff channels after obliteration of the vascular pedicle have been reported. We have encountered 2 cases in which these difficult conditions have resulted in obliteration of the primary blood supply to the Mitrofanoff channels during the reoperative procedure. The intraoperative evaluation, however, was consistent with an adequate collateral blood supply, and no additional measures were taken. Both stomas appeared to be healthy, well perfused, and viable with more than 1 year of follow-up. CASE REPORT CASE 1 A 10-year-old boy presented with a past history of appendicovesicostomy, ileocystoplasty, bladder neck reconstruction, and bilateral ureteral reimFrom the Department of Pediatric Urology, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana Address for correspondence: Mark Cain, M.D., Department of Pediatric Urology, James Whitcomb Riley Hospital for Children, 702 North Barnhill Drive, Suite 4230, Indianapolis, IN 46202. E-mail: [email protected] Submitted: December 29, 2004, accepted (with revisions): March 2, 2005 © 2005 ELSEVIER INC. ALL RIGHTS RESERVED
plants 6 years before for a neuropathic bladder due to caudal regression syndrome. Because of ongoing difficulties with constipation and fecal soiling, the decision was made to pursue an antegrade cecostomy (Malone antegrade continence enema, or MACE procedure) with a cecal flap. At surgery, the adhesions were dense and diffuse, necessitating extensive adhesiolysis. This resulted in the transection of a prominent arterial vessel, which was controlled. Additional dissection revealed that this was definitely the mesoappendix with its appendicular artery. Intraoperative endoscopy was performed and demonstrated healthy mucosa. After more than 1 hour of observation, it was determined that the appendix remained viable. Therefore, no intervention was undertaken, and the stoma remained in use. The appendicovesicostomy channel remained healthy and patent 2 years later, and no problems with its catheterization have developed. CASE 2 A 10-year-old girl with a history of a lipomeningocele and two tethered cord releases was undergoing a right ureteral reimplant. Her previous surgical history included an ileocystoplasty and tapered ileovesicostomy 18 months prior that had appeared, and had functioned, well up to the time of surgery. At laparotomy, the ileum proximal to the previous bowel anastomosis was found to be incarcerated through a very stretched and attenuated ileovesicostomy pedicle. No significant vessels were visible through the very thin mesentery, and no pulse was detectable by palpation or by Doppler ultrasonography. Again, a diligent search for signs of ischemia was undertaken, but the stoma appeared well perfused. The obliterated 0090-4295/05/$30.00 doi:10.1016/j.urology.2005.03.013 657.e11
mesenteric band was divided to prevent recurrent internal hernia. Her stoma remained viable and the catheterizable channel functioned well 1 year after surgery. COMMENT As the number of patients undergoing bowel and bladder reconstruction has increased, so has the incidence of secondary operations, and, hence, the potential for complications. We were unable to find any information in published reports regarding outcomes after ligation of a Mitrofanoff vascular pedicle at the time of a reoperative procedure, but believe that it is a situation that will not be unique. The blood supply to the appendix is well known, as is its inherent variability. The superior mesenteric artery supplies the entire midgut, with its ileocecal branch supplying the ileocecal complex.2 The appendicular artery arises from the iliac ramus in 35% of cases, a division of the ileocecal in 28%, the anterior cecal in 20%, posterior cecal in 12%, ileocecal in 3%, and ascending colic ramus in 2%.3 It runs along the free border of its mesenteriolum and, because no arcades are within this structure, it is believed to be an end artery.4 This accounts for the appendix’s predilection for ischemia. However, the base of the appendix receives a separate blood supply from the anterior and posterior cecal arteries.3 The plasticity of the gastrointestinal microcirculation has been well described in animal models. Ligated rabbit appendicular arteries result in the rapid recruitment of collateral vessels by way of numerous complicated intervascular connec-
657.e12
tions.5 St. Clair et al.1 demonstrated that ligation of the mesenteric pedicle of an ileocystoplasty in a 4-month-old canine model did not result in ischemic complications. Although a long-term decrease in capacity resulted,6 the neocollateral vessels were able to prevent ischemia and tissue death.1,6 These cases highlight the clinical application with both acute and chronic arterial occlusion to an established intestinal graft. Although the chronically stretched pedicle would have had sufficient time to develop an adequate secondary blood supply, even the acute arterial interruption was able to recruit sufficient collaterals to maintain viability. We believe that a mature Mitrofanoff channel can survive both chronic and acute occlusion of its mesenteric pedicle and does not appear to require replacement in this clinical setting. REFERENCES 1. St. Clair SR, Ritchey ML, Hansberry K, et al: Viability and functional characteristics of enterocystoplasty after ligation of the vascular pedicle. J Urol 146: 554 –557, 1991. 2. Schumpelick V, Dreuw B, Ophoff K, et al: Appendix and cecum: embryology, anatomy, and surgical applications. Surg Clin North Am 80: 295–318, 2000. 3. Stelzner F: Die Appendizitis: Handbuch der Inneren Medizin. Berlin, Springer, 1982. 4. Stelzner F, and Lierse W: Etiology of appendicitis. Langenbecks Arch Chir 330(4): 273–284, 1972. 5. Il’in VE: Plasticity of the circulatory bed of the vermiform appendix in the presence of circulatory disorders within it. Arkh Anat Gistol Embriol 70: 70 –76, 1976. 6. Kearse WS Jr, St. Clair SR, Hixson CJ, et al: Functional characteristics of enterocystoplasty after interruption of the mesenteric blood supply. J Urol 150: 593–596, 1993.
UROLOGY 66 (3), 2005
MITROFANOFF CHANNEL SURVIVAL AFTER PEDICLE LIGATION P. D. METCALFE, M. P. CAIN,
AND
R. C. RINK
ABSTRACT In patients who have undergone complex genitourinary reconstruction, additional abdominal surgery is often required. We report 2 cases in which the blood supply to an existing Mitrofanoff channel was divided. In both cases, the conduits appeared to remain well perfused, presumably based on collateral blood supply. Both conduits remained healthy and functioning at more than 1 year of follow-up. UROLOGY 66: 657.e11–657.e12, 2005. © 2005 Elsevier Inc.
T
he pediatric patient who undergoes lower urinary tract reconstruction often requires a continent cutaneous channel to the bladder or cecum, or both. The complex nature of both the reconstruction and the patient may necessitate additional intraabdominal surgery. The subsequent surgery can be very challenging because of the reconfigured anatomy and adhesions. Although experimental evidence has shown that an enterocystoplasty segment can survive after delayed ligation,1 no cases of the viability of Mitrofanoff channels after obliteration of the vascular pedicle have been reported. We have encountered 2 cases in which these difficult conditions have resulted in obliteration of the primary blood supply to the Mitrofanoff channels during the reoperative procedure. The intraoperative evaluation, however, was consistent with an adequate collateral blood supply, and no additional measures were taken. Both stomas appeared to be healthy, well perfused, and viable with more than 1 year of follow-up. CASE REPORT CASE 1 A 10-year-old boy presented with a past history of appendicovesicostomy, ileocystoplasty, bladder neck reconstruction, and bilateral ureteral reimFrom the Department of Pediatric Urology, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana Address for correspondence: Mark Cain, M.D., Department of Pediatric Urology, James Whitcomb Riley Hospital for Children, 702 North Barnhill Drive, Suite 4230, Indianapolis, IN 46202. E-mail: [email protected] Submitted: December 29, 2004, accepted (with revisions): March 2, 2005 © 2005 ELSEVIER INC. ALL RIGHTS RESERVED
plants 6 years before for a neuropathic bladder due to caudal regression syndrome. Because of ongoing difficulties with constipation and fecal soiling, the decision was made to pursue an antegrade cecostomy (Malone antegrade continence enema, or MACE procedure) with a cecal flap. At surgery, the adhesions were dense and diffuse, necessitating extensive adhesiolysis. This resulted in the transection of a prominent arterial vessel, which was controlled. Additional dissection revealed that this was definitely the mesoappendix with its appendicular artery. Intraoperative endoscopy was performed and demonstrated healthy mucosa. After more than 1 hour of observation, it was determined that the appendix remained viable. Therefore, no intervention was undertaken, and the stoma remained in use. The appendicovesicostomy channel remained healthy and patent 2 years later, and no problems with its catheterization have developed. CASE 2 A 10-year-old girl with a history of a lipomeningocele and two tethered cord releases was undergoing a right ureteral reimplant. Her previous surgical history included an ileocystoplasty and tapered ileovesicostomy 18 months prior that had appeared, and had functioned, well up to the time of surgery. At laparotomy, the ileum proximal to the previous bowel anastomosis was found to be incarcerated through a very stretched and attenuated ileovesicostomy pedicle. No significant vessels were visible through the very thin mesentery, and no pulse was detectable by palpation or by Doppler ultrasonography. Again, a diligent search for signs of ischemia was undertaken, but the stoma appeared well perfused. The obliterated 0090-4295/05/$30.00 doi:10.1016/j.urology.2005.03.013 657.e11
mesenteric band was divided to prevent recurrent internal hernia. Her stoma remained viable and the catheterizable channel functioned well 1 year after surgery. COMMENT As the number of patients undergoing bowel and bladder reconstruction has increased, so has the incidence of secondary operations, and, hence, the potential for complications. We were unable to find any information in published reports regarding outcomes after ligation of a Mitrofanoff vascular pedicle at the time of a reoperative procedure, but believe that it is a situation that will not be unique. The blood supply to the appendix is well known, as is its inherent variability. The superior mesenteric artery supplies the entire midgut, with its ileocecal branch supplying the ileocecal complex.2 The appendicular artery arises from the iliac ramus in 35% of cases, a division of the ileocecal in 28%, the anterior cecal in 20%, posterior cecal in 12%, ileocecal in 3%, and ascending colic ramus in 2%.3 It runs along the free border of its mesenteriolum and, because no arcades are within this structure, it is believed to be an end artery.4 This accounts for the appendix’s predilection for ischemia. However, the base of the appendix receives a separate blood supply from the anterior and posterior cecal arteries.3 The plasticity of the gastrointestinal microcirculation has been well described in animal models. Ligated rabbit appendicular arteries result in the rapid recruitment of collateral vessels by way of numerous complicated intervascular connec-
657.e12
tions.5 St. Clair et al.1 demonstrated that ligation of the mesenteric pedicle of an ileocystoplasty in a 4-month-old canine model did not result in ischemic complications. Although a long-term decrease in capacity resulted,6 the neocollateral vessels were able to prevent ischemia and tissue death.1,6 These cases highlight the clinical application with both acute and chronic arterial occlusion to an established intestinal graft. Although the chronically stretched pedicle would have had sufficient time to develop an adequate secondary blood supply, even the acute arterial interruption was able to recruit sufficient collaterals to maintain viability. We believe that a mature Mitrofanoff channel can survive both chronic and acute occlusion of its mesenteric pedicle and does not appear to require replacement in this clinical setting. REFERENCES 1. St. Clair SR, Ritchey ML, Hansberry K, et al: Viability and functional characteristics of enterocystoplasty after ligation of the vascular pedicle. J Urol 146: 554 –557, 1991. 2. Schumpelick V, Dreuw B, Ophoff K, et al: Appendix and cecum: embryology, anatomy, and surgical applications. Surg Clin North Am 80: 295–318, 2000. 3. Stelzner F: Die Appendizitis: Handbuch der Inneren Medizin. Berlin, Springer, 1982. 4. Stelzner F, and Lierse W: Etiology of appendicitis. Langenbecks Arch Chir 330(4): 273–284, 1972. 5. Il’in VE: Plasticity of the circulatory bed of the vermiform appendix in the presence of circulatory disorders within it. Arkh Anat Gistol Embriol 70: 70 –76, 1976. 6. Kearse WS Jr, St. Clair SR, Hixson CJ, et al: Functional characteristics of enterocystoplasty after interruption of the mesenteric blood supply. J Urol 150: 593–596, 1993.
UROLOGY 66 (3), 2005