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Self-expanding, metal stents for malignant colonic obstruction
Clinical Radiology (1998) 53, 237-238
Editorial Self-expanding, Metal Stents for Malignant Colonic Obstruction Self-expanding metal stents are now established treatment for palliation in malignant obstruction of the oesophagus [ 1] and biliary tree [21. Although more expensive than plastic stents, they have proved effective and easy to insert with low morbidity. Wider diameter high radial force stents are now available, and being used to relieve malignant obstruction of the small [3] and large intestine [4-12]. In this issue of Clinical Radiology Wallis et al. [13] describe their experience in stenting obstructing colorectal cancer. The seven patients reported had either advanced disease or associated medical conditions preventing immediate surgery. All were stented successfully without complication and with resolution of obstructive symptoms. Stent insertion proved adequate for long-term palliation in four patients. Definitive surgery was eventually possible in two patients after treatment of concomitant diseases. Stenting failed to provide long-term relief in one patient with a rectal carcinoma in whom the stent was passed at defaecation 7 days after insertion. Where a diagnosis of inoperable colorectal cancer has been established, few would argue against palliative, minimally invasive treatments for acute/subacute obstruction such as laser ablation, alcohol injection or stent insertion. More controversial is the role of stent insertion at the time of initial presentation with acute malignant obstruction, where the resectability of the tumour has not been established. Such patients usually present as an emergency, are in poor physical condition, and are operated upon out of necessity, so that surgery occurs during the period of resuscitation, and before there has been an opportunity to stage the tumour. In this context, surgery carries a high mortality and morbidity [14]. When advanced disease is found at laparotomy, a defunctioning colostomy will be formed, which will then remain with the patient for the rest of their life. Should complete resection of the tumour with primary anastomosis be possible, many surgeons would still choose to fashion a temporary covering stoma, so that definitive surgery will remain a two-stage procedure. Stent insertion for acute malignant obstruction has several advantages. First, it allows immediate bowel decompression with rapid resolution of patient symptoms and restoration of normal intestinal transit. Second, it buys time to allow full resuscitation and to use imaging techniques to assess disease extent. In those patients who are then found to have advanced disease, the stent may provide adequate long-term palliation, avoiding the need for any surgery and an inevitable defunctioning colostomy. On the other hand those with potentially curable disease can be operated on electively, after full oral bowel preparation and with a higher probability for a successful primary resection. Also the proximal colon can be imaged pre-operatively, either endoscopically or radiologically, to exclude any synchronous lesion and to help plan the most appropriate surgical approach. These are cogent arguments in favour of stenting as the primary treatment for acute malignant obstruction. However, some questions remain. Does stent insertion for malignant obstruction reduce surgical complications and improve patient outcome? Is stenting in the acute phase a 9 1998 The Royal College of Radiologists.
cost-effective strategy; particularly given the high initial outlay to cover the cost of the stents themselves? Is stent insertion technically feasible and safe in an unselected population presenting with malignant obstruction? Several recent publications have described the technique of stent insertion using either purely radiological or combined endoscopic/radiologic techniques. These early case series [9,11,12], describing the stenting of mainly left-sided tumours, suggest that although a stent may be inserted successfully, there remains a risk of major complication, such as perforation or stent migration [11]. Which lesions require a combined endoscopic/radiologic approach remains unclear. It seems likely that lesions proximal to the sigmoid colon should be approached endoscopically, as the endoscope can be passed atraumatfcally through any convoluted sigmoid loops, and the stent delivered through the scope over a guidewire under direct endoscopic and radiologic control. Indeed if facilities and expertise were available, this combination would seem optimal for all lesions throughout the colon. One restriction on 'throughthe-scope' endoscopic delivery has been stent size. Recently 10F delivery systems have been developed that can be inserted via standard 3.6mm endoscope instrument channels, allowing placement of stents that expand to 22-mm diameter. Other technical issues include: which type of guide wire to use, how to best define the proximal extent of the stricture, whether lesions should be dilated prior to stent insertion, which size and type of stent and delivery system to use in certain situations, and whether or not prophylactic antibiotics will help to prevent stent-associated infection/inflammation. The latter is of concern to surgeons. If stents are inserted to buy time (usually only a few days) prior to definitive surgery does inflammation and or infection occur around the stent that may make surgery more difficult? This is particularly relevant in low rectal tumours where a colo-anal anastomosis is planned. It is possible that stent insertion may not be recommended in this situation. Provided the stent delivery system can pass through the stricture, dilatation does not appear to be necessary, and is best avoided as it increases the risk of perforation [6]. Self-expanding metal stents may yet prove to be a major advance in the treatment of acute obstruction in colorectal cancer. There is also the potential for coating the stent in anti-tumour agent to deliver chemotherapy directly whilst relieving obstruction. However, before stenting is widely accepted and changes current surgical practice, there must be definitive, prospective, randomized studies showing clear benefits in terms of quality of life, complications, costeffectiveness and mortality. Until these studies are available the high cost and unproved benefit of stenting is likely to restrict its use to palliation only.
REFERENCES 1 Vermeijden JR, Bartelsman JWM, Fockens P, Meijer RCA, Tytgat GNJ. Self-expanding metal stents for palliation of esophagocardial malignancies. Gastrointestinal Endoscopy 1995;41:58-63. 2 Davids PHP, Groen AK, Rauws EAJ, Tytgat GNJ, Huibregtse K. A prospective randomised trial of self-expanding stent versus
238
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4
5
6
7
8
9
CLINICAL RADIOLOGY
polyethylene stents for distal malignant biliary obstruction. Lancet 1992;340:1488-1492. Maetani L, Inoue H, Sato M, Ohashi S, Igarashi Y. Peroral insertion techniques of self-expanding metal stents for malignant gastric outlet and duodenal stenoses. Gastrointestinal Endoscopy 1996;44:468-471. Dohomoto M. New method-endoscopic implantation of rectal stent in palliative treatment of malignant stenosis. Endoscopia Digestiva 1991;3:1507-1512. Spinelli P, Dal Fante M, Mancini A. Self-expanding mesh stent for endoscopic palliation of rectal obstructing tumours: a preliminary report. Surgical Endoscopy 1992;6:72-74. Itabasbi M, Hamano K, Kameoka S, Ashina K. Self-expanding stainless steel stent application in rectosigmoid stricture. Diseases of the Colon and Rectum 1993;36:508-511. Tejero E, Mainar A, Fernandez L, Tobit R, DeGregorio MA. New procedure for the treatment of colorectal neoplastic obstructions. Diseases of the Colon and Rectum 1994;37:1158-1159. Rey JF, Romanczyk T, Greff M. Metal stents for palliation of rectal carcinoma: a preliminary report on 12 patients. Endoscopy 1995;27:501-504. Saida Y, Sumiyama Y, Nagao J, Takase M. Stent endoprosthesis for obstructing colorectal cancers. Diseases of the Colon and Rectum 1996;39:552-555.
10 Mainar A, Tejero E, Maynar M, Ferral H, Casteneda-Zuniga W. Colorectal obstruction: treatment with metal stents. Radiology 1996;198:761-764. 11 Canon CL, Baron TH, Morgan DE, Dean PA, Koehler RE. Treatment of colonic obstruction with expandable metal stents: Radiologic features. American Journal of Roentg enology 1997;168:199-205. 12 Tejero E, Fernandez-Lobato R, Mainar A et al. Initial results of a new procedure for treatment of malignant obstruction of the left colon. Diseases of the Colon and Rectum 1997;40:432-436. 13 Wallis F, Campbell KL, Eremin O, Hussey JK. Self-expanding metal stents in the management of colorectal carcinoma - a preliminary report. Clinical Radiology 1998;53:251-254. 14 Barillari P, Aurello P, DeAngelis R, Valabrega S, Ramacciato G, D'Angelo F. Management and survival of patients affected with obstructive colorectal cancer. International Surgery 1992;7:251-255.
B. P. SAUNDERS* C. BARTRAM*
Wolfson Unit for Endoscopy and *Intestinal Imaging, St. Mark's Hospital, Harrow, Middlesex HA1 3UJ, UK
9 1998 The Royal College of Radiologists, ClinicalRadiology, 53, 237-238.
Editorial Self-expanding, Metal Stents for Malignant Colonic Obstruction Self-expanding metal stents are now established treatment for palliation in malignant obstruction of the oesophagus [ 1] and biliary tree [21. Although more expensive than plastic stents, they have proved effective and easy to insert with low morbidity. Wider diameter high radial force stents are now available, and being used to relieve malignant obstruction of the small [3] and large intestine [4-12]. In this issue of Clinical Radiology Wallis et al. [13] describe their experience in stenting obstructing colorectal cancer. The seven patients reported had either advanced disease or associated medical conditions preventing immediate surgery. All were stented successfully without complication and with resolution of obstructive symptoms. Stent insertion proved adequate for long-term palliation in four patients. Definitive surgery was eventually possible in two patients after treatment of concomitant diseases. Stenting failed to provide long-term relief in one patient with a rectal carcinoma in whom the stent was passed at defaecation 7 days after insertion. Where a diagnosis of inoperable colorectal cancer has been established, few would argue against palliative, minimally invasive treatments for acute/subacute obstruction such as laser ablation, alcohol injection or stent insertion. More controversial is the role of stent insertion at the time of initial presentation with acute malignant obstruction, where the resectability of the tumour has not been established. Such patients usually present as an emergency, are in poor physical condition, and are operated upon out of necessity, so that surgery occurs during the period of resuscitation, and before there has been an opportunity to stage the tumour. In this context, surgery carries a high mortality and morbidity [14]. When advanced disease is found at laparotomy, a defunctioning colostomy will be formed, which will then remain with the patient for the rest of their life. Should complete resection of the tumour with primary anastomosis be possible, many surgeons would still choose to fashion a temporary covering stoma, so that definitive surgery will remain a two-stage procedure. Stent insertion for acute malignant obstruction has several advantages. First, it allows immediate bowel decompression with rapid resolution of patient symptoms and restoration of normal intestinal transit. Second, it buys time to allow full resuscitation and to use imaging techniques to assess disease extent. In those patients who are then found to have advanced disease, the stent may provide adequate long-term palliation, avoiding the need for any surgery and an inevitable defunctioning colostomy. On the other hand those with potentially curable disease can be operated on electively, after full oral bowel preparation and with a higher probability for a successful primary resection. Also the proximal colon can be imaged pre-operatively, either endoscopically or radiologically, to exclude any synchronous lesion and to help plan the most appropriate surgical approach. These are cogent arguments in favour of stenting as the primary treatment for acute malignant obstruction. However, some questions remain. Does stent insertion for malignant obstruction reduce surgical complications and improve patient outcome? Is stenting in the acute phase a 9 1998 The Royal College of Radiologists.
cost-effective strategy; particularly given the high initial outlay to cover the cost of the stents themselves? Is stent insertion technically feasible and safe in an unselected population presenting with malignant obstruction? Several recent publications have described the technique of stent insertion using either purely radiological or combined endoscopic/radiologic techniques. These early case series [9,11,12], describing the stenting of mainly left-sided tumours, suggest that although a stent may be inserted successfully, there remains a risk of major complication, such as perforation or stent migration [11]. Which lesions require a combined endoscopic/radiologic approach remains unclear. It seems likely that lesions proximal to the sigmoid colon should be approached endoscopically, as the endoscope can be passed atraumatfcally through any convoluted sigmoid loops, and the stent delivered through the scope over a guidewire under direct endoscopic and radiologic control. Indeed if facilities and expertise were available, this combination would seem optimal for all lesions throughout the colon. One restriction on 'throughthe-scope' endoscopic delivery has been stent size. Recently 10F delivery systems have been developed that can be inserted via standard 3.6mm endoscope instrument channels, allowing placement of stents that expand to 22-mm diameter. Other technical issues include: which type of guide wire to use, how to best define the proximal extent of the stricture, whether lesions should be dilated prior to stent insertion, which size and type of stent and delivery system to use in certain situations, and whether or not prophylactic antibiotics will help to prevent stent-associated infection/inflammation. The latter is of concern to surgeons. If stents are inserted to buy time (usually only a few days) prior to definitive surgery does inflammation and or infection occur around the stent that may make surgery more difficult? This is particularly relevant in low rectal tumours where a colo-anal anastomosis is planned. It is possible that stent insertion may not be recommended in this situation. Provided the stent delivery system can pass through the stricture, dilatation does not appear to be necessary, and is best avoided as it increases the risk of perforation [6]. Self-expanding metal stents may yet prove to be a major advance in the treatment of acute obstruction in colorectal cancer. There is also the potential for coating the stent in anti-tumour agent to deliver chemotherapy directly whilst relieving obstruction. However, before stenting is widely accepted and changes current surgical practice, there must be definitive, prospective, randomized studies showing clear benefits in terms of quality of life, complications, costeffectiveness and mortality. Until these studies are available the high cost and unproved benefit of stenting is likely to restrict its use to palliation only.
REFERENCES 1 Vermeijden JR, Bartelsman JWM, Fockens P, Meijer RCA, Tytgat GNJ. Self-expanding metal stents for palliation of esophagocardial malignancies. Gastrointestinal Endoscopy 1995;41:58-63. 2 Davids PHP, Groen AK, Rauws EAJ, Tytgat GNJ, Huibregtse K. A prospective randomised trial of self-expanding stent versus
238
3
4
5
6
7
8
9
CLINICAL RADIOLOGY
polyethylene stents for distal malignant biliary obstruction. Lancet 1992;340:1488-1492. Maetani L, Inoue H, Sato M, Ohashi S, Igarashi Y. Peroral insertion techniques of self-expanding metal stents for malignant gastric outlet and duodenal stenoses. Gastrointestinal Endoscopy 1996;44:468-471. Dohomoto M. New method-endoscopic implantation of rectal stent in palliative treatment of malignant stenosis. Endoscopia Digestiva 1991;3:1507-1512. Spinelli P, Dal Fante M, Mancini A. Self-expanding mesh stent for endoscopic palliation of rectal obstructing tumours: a preliminary report. Surgical Endoscopy 1992;6:72-74. Itabasbi M, Hamano K, Kameoka S, Ashina K. Self-expanding stainless steel stent application in rectosigmoid stricture. Diseases of the Colon and Rectum 1993;36:508-511. Tejero E, Mainar A, Fernandez L, Tobit R, DeGregorio MA. New procedure for the treatment of colorectal neoplastic obstructions. Diseases of the Colon and Rectum 1994;37:1158-1159. Rey JF, Romanczyk T, Greff M. Metal stents for palliation of rectal carcinoma: a preliminary report on 12 patients. Endoscopy 1995;27:501-504. Saida Y, Sumiyama Y, Nagao J, Takase M. Stent endoprosthesis for obstructing colorectal cancers. Diseases of the Colon and Rectum 1996;39:552-555.
10 Mainar A, Tejero E, Maynar M, Ferral H, Casteneda-Zuniga W. Colorectal obstruction: treatment with metal stents. Radiology 1996;198:761-764. 11 Canon CL, Baron TH, Morgan DE, Dean PA, Koehler RE. Treatment of colonic obstruction with expandable metal stents: Radiologic features. American Journal of Roentg enology 1997;168:199-205. 12 Tejero E, Fernandez-Lobato R, Mainar A et al. Initial results of a new procedure for treatment of malignant obstruction of the left colon. Diseases of the Colon and Rectum 1997;40:432-436. 13 Wallis F, Campbell KL, Eremin O, Hussey JK. Self-expanding metal stents in the management of colorectal carcinoma - a preliminary report. Clinical Radiology 1998;53:251-254. 14 Barillari P, Aurello P, DeAngelis R, Valabrega S, Ramacciato G, D'Angelo F. Management and survival of patients affected with obstructive colorectal cancer. International Surgery 1992;7:251-255.
B. P. SAUNDERS* C. BARTRAM*
Wolfson Unit for Endoscopy and *Intestinal Imaging, St. Mark's Hospital, Harrow, Middlesex HA1 3UJ, UK
9 1998 The Royal College of Radiologists, ClinicalRadiology, 53, 237-238.