A Continent Colostomy: The Magnetic Stoma Cap Joel J. Bauer, MD, New York, New York Martin G. Wertkin, MD, New York, New York Irwin M. Gelernt, MD, New York, New York lsadore Kreel, MD, New York, New York
Approximately 50,000 permanent colostomies are performed in the United States each year [I]. Most American surgeons attempt to teach patients to irrigate their colostomies every other day. There are no published statistics on the number of patients who are unable to irrigate their colostomies properly; however, a significant proportion of patients with colostomies must wear a colostomy bag. Even among patients able to irrigate daily or every other day, an appliance is often necessary. Mazier et al [1] surveyed 105 patients who irrigated their colostomies on a regular basis. Nine patients (8.6 per cent) wore a bag at all times and another fifty-nine patients (55 per cent) wore a bag when going out socially. In England, most surgeons believe in “natural evacuation” rather than irrigation. Although the English diet is somewhat more uniform and bowel habits are generally more regular, 50 to 70 per cent of British patients with colostomies are not regular enough to avoid wearing a permanent colostomy bag [WI. Feustel and Hennig [4] in 1974 at the University of Erlangen, Germany, developed a device designed to make colostomy care easier and more convenient, eliminating the need for a colostomy bag. The device consists of a samarium-cobalt magnetic ring encased in Palaces@ (methyl methacrylate). (Figure 1.) The core of the cap provides a constant force of 4 to 5 newtons over a distance of 10 to 30 mm. This ring is implanted subcutaneously in the abdominal wall surrounding the colostomy. Four to six weeks after surgery, the stoma is obturated by the magnetic plug. The magnetic force between the ring and the plug is sufficient to keep the stoma occluded, hence, achieving continence. Feustel and Hennig [5] recently reported the successful use of this system in sixteen patients. The present experiment was designed to test the effectiveness and study possible side effects of the magFrom the Department of Surgery, Mount Sinai School of Medicine of the Cii University of New York, New York, New York. Reprint requests should be addressed to Joel J. Bauer, MD, Department of Surgery, Mount Sinai School of Medicine 01 the City University of New York, Fifth Avenue and 100th Street, New York, New York 10029.
334
netic colostomy device in laboratory animals. Possible toxicity to uncoated cobalt magnets was also studied. Material and Methods Twenty-five female mongrel dogs, weighing 6 to 22 kg, were divided into three groups. Group 1. Group I consisted of ten dogs, all weighing 8 to 10 kg. Each dog had a standard weight of samarium-cobalt magnet (without the methyl methacrylate coating) implanted under the muscle fascia in the left flank. The weight of the implanted magnet per kilogram body weight was equivalent to that used in humans. In one dog the magnet was removed after four days because of erythema surrounding the wound. The skin and fascial pocket containing the magnet was excised. In three dogs the magnets were removed after six weeks, in three after two months, and in three after eight months. During the experiment the following studies were performed: serum cobalt, serum electrolytes, complete blood counts, and weekly prothrombin time determinations. At the end of the experimental period the magnet and the surrounding tissue pocket were excised in each animal and the animal sacrificed. Each pocket was studied histologically, and postmortem and histopathologic examinations of the liver, pancreas, heart, spleen, kidney, and thyroid were performed. Tissue cobalt levels in these organs were measured by aspiration-atomic absorption spectrophotometry. Group II. Group II consisted of twelve dogs. Six of these dogs weighed 6 to 10 kg and six weighed 16 to 22 kg. Each
Figure 1. Methyl mefhacryiafe-encased samarium-cobali magnetic ring and plastic-coated magnetic plug.
The American Journal of Surgery
Magnetic Stoma Cap
dog underwent laparotomy and end colostomy in the descending colon. The distal end of the colon was oversewn and returned into the peritoneal cavity. The magnetic ring was implanted intramuscularly on the left side of the abdomen and the fascia was closed around the ring using interrupted absorbable sutures. The proximal end of the divided colon was delivered through the magnetic ring and matured to the skin. (Figure 2.) Before the skin was closed, 1 gm of ampicillin powder was placed into the main incision and into the pocket containing the magnetic ring. After four weeks, the magnetic stoma caps were inserted into the stoma of each dog (Figure 3), and continence was assessed daily. The stoma caps were inserted in the morning and removed in the evening, permitting the dogs to evacuate feces during the night. Complete blood counts and serum cobalt levels were determined weekly. Three dogs were sacrificed three months and three were sacrificed eight months after implantation. The remaining six dogs are being maintained for ongoing long-term study. Postmortem studies similar to those performed in group I were repeated in each animal. Group III. End colostomies were performed in three dogs. The technic was exactly the same as in group II, but the magnetic rings were not implanted. Serum cobalt levels and complete blood counts were determined weekly. The animals were sacrificed three months postoperatively, and histopathologic examination and tissue cobalt determinations were performed on the organs studied in groups I and II.
Results Group I. All dogs tolerated implantation of raw cobalt well. There were transient elevations of the white cell count, which returned to normal within two to three weeks after implantation. There were no clinical wound infections. Wound cultures grew Staphylococcus albus from all dogs and beta-hemolytic streptococcus from one dog. Serum cobalt levels were within normal limits. Several of the dogs had isolated minimal elevations in serum cobalt levels, but in all cases the cobalt levels returned to within normal limits by the next determination and remained within the normal range. (Figure 4.) Results of histopathologic examination and tissue cobalt levels of liver, pancreas, spleen, heart, kidney, and thyroid were within normal limits. Group II. All dogs in this group tolerated surgery
well. Eleven of the twelve were completely continent of stool while the stoma caps were in place. In one dog the colostomy was placed too caudad and hence was too close to the left hind leg. Movement of the leg prevented a proper fit between the plug and the stoma, and the cap had a tendency to fall out when the dog ambulated. This stoma was therefore incontinent.
Figure 2. A, preparation of colostomy site. B, development of “pocket” between external and internal oblige muscles. C, insertion of magnetic rtng into pocket. D and E, approximation of internal and external oblique muscles to isolate ring. F, delivery of end of colon through the colostomy site. G, maturation of the colostomy. H, cross section of abdominal wall demonstrating position of the ring.
335
Bauer et al
Figure 3. Magnetic ring implanted In abdominal wall with magnetic stoma cap in place.
Two dogs developed strictures of the colostomy at the skin level. Both of these dogs were small (8 to 10 kg in weight), and because of a laboratory oversight both dogs went without their stomas being capped for three weeks. In both animals the strictures were dilated digitally, and no further stoma1 problems were encountered. One dog developed a peristomal dehiscence of the skin and subcutaneous tissue. This was the first dog in group II to be studied, and the magnetic ring was implanted subcutaneously. In all subsequent dogs, the ring was implanted between the external and internal oblique muscles, and this complication was not observed again. There were no other significant complications. There were no wound or peristomal infections and no erosion of the colon or fistula. Serum cobalt levels in this group were within normal limits. Pathologic features of tissue from sacrificed dogs was unremarkable except in two cases. One dog was found to have extramedullary hematopoiesis in the liver, and the other had very mild myofibrillar degeneration in DOG SERUM COBALT LEVELS 1.8 _________________________________.____________.____-: : LIpperhml dn0rmo/ 5 15VI o--o GROUP I z 14“Uncoated”
: ;
~0
1.2-
Sl.O-
4 Unexplotned
CON-0 TAOL
5
IO WEEKS
15
sornor~~m
GROUP II Methyl methmqlote mognetlc ungr
20 AFTER
25
cobalt
A magnetic colostomy system with sustained controlled continence should provide the patient with an opportunity to live free of irrigations and colostomy bags. Personal communication and observation of such patients under treatment at the University of Erlangen, Germany, tends to confirm these conclusions. This study was designed to create an appropriate experimental model on which toxicity
magnets
35
II
1
40
45
IMPLANTATION
Figure 4. Median serum cobalt levels in groups I and II.
336
Comments
coated
high level-group
30
the heart, which was not believed by the pathologist to be of significance. Histopathologic examination of the soft tissue surrounding the magnetic ring revealed fibrosis and chronic inflammation. (Figure 5.) In the six dogs that were sacrificed, cobalt levels of liver, pancreas, thyroid, spleen, kidney, and heart were within normal limits. (Figure 6.) Group III (Control). There were no significant elevations in tissue or serum cobalt levels. In one dog extramedullary hematopoiesis in the liver was noted.
Figure 5. Histopatho!ogk features of intramuscutar pocket surrounding the magnetic ring, demonstrating chronic inf/ammatory and fibrotic react/on.
The
American Journal 04 Suqpry
Magnetic
1
Stoma
Cap
myofibrillar degeneration seen in one dog was believed so slight that it was of questionable significance. The extramedullary hematopoiesis found in the liver of one dog is commonly found in mongrels with parasitic infection and was believed unrelated to cobalt toxicity. Serum and organ cobalt levels remained low on repeated determinations in all dogs. Summary
g
00
LIVER
THYROID
PANCREAS
SPLEEN
KIDNEY
HEART
Figure 6. Compartson of tissue cobatt level between control and group II.
studies could be performed and mechanical and technical problems identified. Our results indicate that these colostomies are continent to fecal material. One dog was occasionally incontinent due to poor placement of the stoma. Colostomy strictures seen in two small dogs whose stomas were left uncapped for three weeks were not present when larger dogs were used and when the stomas were capped daily. The peristomal dehiscence which occurred in one of the early dogs was believed due to subcutaneous placement of the ring. These dogs had very little subcutaneous fat and this complication was not seen when the rings were implanted in an intramuscular position. None of the other dogs showed signs of pressure necrosis of the skin around the stoma. The Erlangen study with 160 patients reported only four patients in whom peristomal dehiscences occurred [4]. Chronic administration of cobalt salts in humans has been shown to produce goiter, with or without evidence of thyroid dysfunction, as well as toxicity to alpha cells of the pancreas [6,7]. No thyroid or pancreatic abnormalities were discovered in any of the dogs in the present experiment. The degree of
Volume 134, September 1977
An apparatus to create continence in an end leftsided colostomy in dogs is assessed. The device consists of a samarium-cobalt magnetic ring encased in methyl methacrylate and a magnetic cap. The ring is implanted in the abdominal wall and the colon delivered through it and matured to the skin. The stoma is later obturated by the magnetic cap to provide continence. Ten dogs exposed to “uncoated” samarium-cobalt magnets for periods of up to eight months showed no elevation of cobalt levels in the serum or tissues and no histopathologic changes on postmortem examination. In twelve dogs, magnetic rings were used to create continent colostomies. Eleven of twelve dogs followed for periods up to eight months were continent and tolerated the appliance well. One ring was extruded after a peristomal skin dehiscence occurred. Two skin strictures appeared and were readily controlled by digital dilatation. Sinus, fistula, or infection were not seen. Clinical application of this device is discussed. References 1. Mazier WP, Dignan RD. Capehart RJ. Smith BG: Effective colostomy irrigation. Surg Gynecol Obsfet 142: 905, 1976. 2. Griffin M: Survey of the incapacity of patients with permanent colostomy Proc R Sot Med 66: 204, 1973. 3. Mendelsson AN: Management of the colonic stoma. Surg Gynecol Obstet 129: 1046, 1969. 4. Feustel H, Hennig G: Personal communication, 1974. 5. Feustel H, Hennig G: Kontinente Kolostomie durch Magnetverschluss Msch Med Wochenschr 100: 1063. 1975. 6. Arena JM: Poisoning, 3rd ed. Springfield, Charles C Thomas, 1974. 7. Thienes CH, Haley TJ: Clinical Toxicology, 5th ed. Philadelphia, Lea & Febiger, 1972.
337
Approximately 50,000 permanent colostomies are performed in the United States each year [I]. Most American surgeons attempt to teach patients to irrigate their colostomies every other day. There are no published statistics on the number of patients who are unable to irrigate their colostomies properly; however, a significant proportion of patients with colostomies must wear a colostomy bag. Even among patients able to irrigate daily or every other day, an appliance is often necessary. Mazier et al [1] surveyed 105 patients who irrigated their colostomies on a regular basis. Nine patients (8.6 per cent) wore a bag at all times and another fifty-nine patients (55 per cent) wore a bag when going out socially. In England, most surgeons believe in “natural evacuation” rather than irrigation. Although the English diet is somewhat more uniform and bowel habits are generally more regular, 50 to 70 per cent of British patients with colostomies are not regular enough to avoid wearing a permanent colostomy bag [WI. Feustel and Hennig [4] in 1974 at the University of Erlangen, Germany, developed a device designed to make colostomy care easier and more convenient, eliminating the need for a colostomy bag. The device consists of a samarium-cobalt magnetic ring encased in Palaces@ (methyl methacrylate). (Figure 1.) The core of the cap provides a constant force of 4 to 5 newtons over a distance of 10 to 30 mm. This ring is implanted subcutaneously in the abdominal wall surrounding the colostomy. Four to six weeks after surgery, the stoma is obturated by the magnetic plug. The magnetic force between the ring and the plug is sufficient to keep the stoma occluded, hence, achieving continence. Feustel and Hennig [5] recently reported the successful use of this system in sixteen patients. The present experiment was designed to test the effectiveness and study possible side effects of the magFrom the Department of Surgery, Mount Sinai School of Medicine of the Cii University of New York, New York, New York. Reprint requests should be addressed to Joel J. Bauer, MD, Department of Surgery, Mount Sinai School of Medicine 01 the City University of New York, Fifth Avenue and 100th Street, New York, New York 10029.
334
netic colostomy device in laboratory animals. Possible toxicity to uncoated cobalt magnets was also studied. Material and Methods Twenty-five female mongrel dogs, weighing 6 to 22 kg, were divided into three groups. Group 1. Group I consisted of ten dogs, all weighing 8 to 10 kg. Each dog had a standard weight of samarium-cobalt magnet (without the methyl methacrylate coating) implanted under the muscle fascia in the left flank. The weight of the implanted magnet per kilogram body weight was equivalent to that used in humans. In one dog the magnet was removed after four days because of erythema surrounding the wound. The skin and fascial pocket containing the magnet was excised. In three dogs the magnets were removed after six weeks, in three after two months, and in three after eight months. During the experiment the following studies were performed: serum cobalt, serum electrolytes, complete blood counts, and weekly prothrombin time determinations. At the end of the experimental period the magnet and the surrounding tissue pocket were excised in each animal and the animal sacrificed. Each pocket was studied histologically, and postmortem and histopathologic examinations of the liver, pancreas, heart, spleen, kidney, and thyroid were performed. Tissue cobalt levels in these organs were measured by aspiration-atomic absorption spectrophotometry. Group II. Group II consisted of twelve dogs. Six of these dogs weighed 6 to 10 kg and six weighed 16 to 22 kg. Each
Figure 1. Methyl mefhacryiafe-encased samarium-cobali magnetic ring and plastic-coated magnetic plug.
The American Journal of Surgery
Magnetic Stoma Cap
dog underwent laparotomy and end colostomy in the descending colon. The distal end of the colon was oversewn and returned into the peritoneal cavity. The magnetic ring was implanted intramuscularly on the left side of the abdomen and the fascia was closed around the ring using interrupted absorbable sutures. The proximal end of the divided colon was delivered through the magnetic ring and matured to the skin. (Figure 2.) Before the skin was closed, 1 gm of ampicillin powder was placed into the main incision and into the pocket containing the magnetic ring. After four weeks, the magnetic stoma caps were inserted into the stoma of each dog (Figure 3), and continence was assessed daily. The stoma caps were inserted in the morning and removed in the evening, permitting the dogs to evacuate feces during the night. Complete blood counts and serum cobalt levels were determined weekly. Three dogs were sacrificed three months and three were sacrificed eight months after implantation. The remaining six dogs are being maintained for ongoing long-term study. Postmortem studies similar to those performed in group I were repeated in each animal. Group III. End colostomies were performed in three dogs. The technic was exactly the same as in group II, but the magnetic rings were not implanted. Serum cobalt levels and complete blood counts were determined weekly. The animals were sacrificed three months postoperatively, and histopathologic examination and tissue cobalt determinations were performed on the organs studied in groups I and II.
Results Group I. All dogs tolerated implantation of raw cobalt well. There were transient elevations of the white cell count, which returned to normal within two to three weeks after implantation. There were no clinical wound infections. Wound cultures grew Staphylococcus albus from all dogs and beta-hemolytic streptococcus from one dog. Serum cobalt levels were within normal limits. Several of the dogs had isolated minimal elevations in serum cobalt levels, but in all cases the cobalt levels returned to within normal limits by the next determination and remained within the normal range. (Figure 4.) Results of histopathologic examination and tissue cobalt levels of liver, pancreas, spleen, heart, kidney, and thyroid were within normal limits. Group II. All dogs in this group tolerated surgery
well. Eleven of the twelve were completely continent of stool while the stoma caps were in place. In one dog the colostomy was placed too caudad and hence was too close to the left hind leg. Movement of the leg prevented a proper fit between the plug and the stoma, and the cap had a tendency to fall out when the dog ambulated. This stoma was therefore incontinent.
Figure 2. A, preparation of colostomy site. B, development of “pocket” between external and internal oblige muscles. C, insertion of magnetic rtng into pocket. D and E, approximation of internal and external oblique muscles to isolate ring. F, delivery of end of colon through the colostomy site. G, maturation of the colostomy. H, cross section of abdominal wall demonstrating position of the ring.
335
Bauer et al
Figure 3. Magnetic ring implanted In abdominal wall with magnetic stoma cap in place.
Two dogs developed strictures of the colostomy at the skin level. Both of these dogs were small (8 to 10 kg in weight), and because of a laboratory oversight both dogs went without their stomas being capped for three weeks. In both animals the strictures were dilated digitally, and no further stoma1 problems were encountered. One dog developed a peristomal dehiscence of the skin and subcutaneous tissue. This was the first dog in group II to be studied, and the magnetic ring was implanted subcutaneously. In all subsequent dogs, the ring was implanted between the external and internal oblique muscles, and this complication was not observed again. There were no other significant complications. There were no wound or peristomal infections and no erosion of the colon or fistula. Serum cobalt levels in this group were within normal limits. Pathologic features of tissue from sacrificed dogs was unremarkable except in two cases. One dog was found to have extramedullary hematopoiesis in the liver, and the other had very mild myofibrillar degeneration in DOG SERUM COBALT LEVELS 1.8 _________________________________.____________.____-: : LIpperhml dn0rmo/ 5 15VI o--o GROUP I z 14“Uncoated”
: ;
~0
1.2-
Sl.O-
4 Unexplotned
CON-0 TAOL
5
IO WEEKS
15
sornor~~m
GROUP II Methyl methmqlote mognetlc ungr
20 AFTER
25
cobalt
A magnetic colostomy system with sustained controlled continence should provide the patient with an opportunity to live free of irrigations and colostomy bags. Personal communication and observation of such patients under treatment at the University of Erlangen, Germany, tends to confirm these conclusions. This study was designed to create an appropriate experimental model on which toxicity
magnets
35
II
1
40
45
IMPLANTATION
Figure 4. Median serum cobalt levels in groups I and II.
336
Comments
coated
high level-group
30
the heart, which was not believed by the pathologist to be of significance. Histopathologic examination of the soft tissue surrounding the magnetic ring revealed fibrosis and chronic inflammation. (Figure 5.) In the six dogs that were sacrificed, cobalt levels of liver, pancreas, thyroid, spleen, kidney, and heart were within normal limits. (Figure 6.) Group III (Control). There were no significant elevations in tissue or serum cobalt levels. In one dog extramedullary hematopoiesis in the liver was noted.
Figure 5. Histopatho!ogk features of intramuscutar pocket surrounding the magnetic ring, demonstrating chronic inf/ammatory and fibrotic react/on.
The
American Journal 04 Suqpry
Magnetic
1
Stoma
Cap
myofibrillar degeneration seen in one dog was believed so slight that it was of questionable significance. The extramedullary hematopoiesis found in the liver of one dog is commonly found in mongrels with parasitic infection and was believed unrelated to cobalt toxicity. Serum and organ cobalt levels remained low on repeated determinations in all dogs. Summary
g
00
LIVER
THYROID
PANCREAS
SPLEEN
KIDNEY
HEART
Figure 6. Compartson of tissue cobatt level between control and group II.
studies could be performed and mechanical and technical problems identified. Our results indicate that these colostomies are continent to fecal material. One dog was occasionally incontinent due to poor placement of the stoma. Colostomy strictures seen in two small dogs whose stomas were left uncapped for three weeks were not present when larger dogs were used and when the stomas were capped daily. The peristomal dehiscence which occurred in one of the early dogs was believed due to subcutaneous placement of the ring. These dogs had very little subcutaneous fat and this complication was not seen when the rings were implanted in an intramuscular position. None of the other dogs showed signs of pressure necrosis of the skin around the stoma. The Erlangen study with 160 patients reported only four patients in whom peristomal dehiscences occurred [4]. Chronic administration of cobalt salts in humans has been shown to produce goiter, with or without evidence of thyroid dysfunction, as well as toxicity to alpha cells of the pancreas [6,7]. No thyroid or pancreatic abnormalities were discovered in any of the dogs in the present experiment. The degree of
Volume 134, September 1977
An apparatus to create continence in an end leftsided colostomy in dogs is assessed. The device consists of a samarium-cobalt magnetic ring encased in methyl methacrylate and a magnetic cap. The ring is implanted in the abdominal wall and the colon delivered through it and matured to the skin. The stoma is later obturated by the magnetic cap to provide continence. Ten dogs exposed to “uncoated” samarium-cobalt magnets for periods of up to eight months showed no elevation of cobalt levels in the serum or tissues and no histopathologic changes on postmortem examination. In twelve dogs, magnetic rings were used to create continent colostomies. Eleven of twelve dogs followed for periods up to eight months were continent and tolerated the appliance well. One ring was extruded after a peristomal skin dehiscence occurred. Two skin strictures appeared and were readily controlled by digital dilatation. Sinus, fistula, or infection were not seen. Clinical application of this device is discussed. References 1. Mazier WP, Dignan RD. Capehart RJ. Smith BG: Effective colostomy irrigation. Surg Gynecol Obsfet 142: 905, 1976. 2. Griffin M: Survey of the incapacity of patients with permanent colostomy Proc R Sot Med 66: 204, 1973. 3. Mendelsson AN: Management of the colonic stoma. Surg Gynecol Obstet 129: 1046, 1969. 4. Feustel H, Hennig G: Personal communication, 1974. 5. Feustel H, Hennig G: Kontinente Kolostomie durch Magnetverschluss Msch Med Wochenschr 100: 1063. 1975. 6. Arena JM: Poisoning, 3rd ed. Springfield, Charles C Thomas, 1974. 7. Thienes CH, Haley TJ: Clinical Toxicology, 5th ed. Philadelphia, Lea & Febiger, 1972.
337
