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Airway complication of expandable stents
Letters to the Editor
cutaneous low molecular weight heparin as an outpatient as suggested by Dr. Rutgeerts, rather than hospitalization for intravenous heparin, is intriguing. Low molecular weight heparin in appropriate doses has been shown to be an effective treatment for acute deep venous thrombosis and pulmonary embolism. Therefore it may be reasonable to assume that its use in this case would satisfactorily prevent complications related to the mechanical valve. The third case deals with use of aspirin or NSAIDs before colonoscopy. These agents affect thromboxane A2-dependent platelet aggregation by means of inhibition of platelet cyclooxygenase. There are no control/ed data documenting a risk of increased bleeding after polypectomy. If the patient has taken aspirin up until 2 days before the colonoscopy, I agree with Dr. Wang and would perform the procedure as planned. There are practical problems with an absolute proscription against the use of aspirin or other anti-plateletlanti-inflammatory agents before colonoscopy. Some patients may absolutely require these agents for prophylaxis against stroke, treatment of severe arthritis, etc. Also, many prescription and over-the-counter products contain these compounds so it may not be possible always to provide patients with a complete list of medications to avoid. Furthermore, what is a colonoscopist to do with the patient with a pedunculated polyp in the descending colon who has already ingested a preparation solution, taken a day off work, come with a driver, and then is found to have taken aspirin 2 days before the procedure for a sporadic headache or back sprain? If desired by the individual colonoscopist, it is reasonable to make a good faith effort to ask patients to refrain from the use of these agents for several days before and after colonoscopy. However, if they are unable to do so for medical reasons or otherwise do not comply with the request, colonoscopy and polypectomy should be performed for the 1.5 cm polyp in the descending colon. For the fourth question, I agree that in the general population routine performances of blood tests (CSC, PT/PTT) before polypectomy to detect a potential coagulation defect are unnecessary. However, Dr. Llorens is correct in stating that a good clinical history before polypectomy is essential. Patients with known or suspected chronic liver disease or a personal or family history of excessive bleeding after surgery, tooth extraction, lacerations, or other trauma should undergo screening laboratory tests including CSC with platelet count, PT/PTI, bleeding time, and fibrinogen levels before endoscopic polypectomy. The American Society for Gastrointestinal Endoscopy will soon distribute a document from its Standards of
136
GASTROINTESTINAL ENDOSCOPY
Practice Committee entitled "Guideline on the Management of Anticoagulation and Antiplatelet Therapy for Endoscopic Procedures" (published in the December 1998 issue of Gastrointestinal Endoscopy). The reader is referred to this document for further discussion and references related to this topic. MD Cleveland, Ohio
GREGORY ZUCCARO, JR.,
Editor's comment. The patient with a primary coagulation disorder may begin bleeding several days after polypectomy, as can the patient who is re-started on Coumadin. A warning must be given to the patient as to this possibility. I suggest that they remain close to the medical center for at least 1 week post-polypectomy. The use of low molecular weight heparin for anticoagulation substitution for warfarin has not been published, but Dr. Rutgeerts, who is always a cautious and careful investigator, raises an interesting point. I do ask that aspirin be discontinued 1 week before colonoscopy, but still remove polyps if they have not complied with that request. Routine screening blood tests are unnecessary before polypectomy unless there is a historic suspicion of a bleeding tendency. f use endoclips to further ensure hemostasis postpolypectomy in patients with a known hematologic bleeding diathesis.
Airway complication of expandable stents To the Editor: Dasgupta et al. l report 2 cases in which placement of an expandable stent in the esophagus was complicated by respiratory compromise. Diagnosis was confirmed by bronchoscopy, but because these particular stents (Wallstent; Schneider, Plymouth, Minn.l could not be removed after placement, the patients required tracheobronchial stenting or laser therapy to maintain airway patency. The authors recommend performing bronchoscopy to detect airway compromise during stent deployment; alternatively they suggest passage of a large dilator with observation before stent placement. We recently experienced a similar airway problem while stenting a malignant stricture of the upper esophagus. The patient was an SO-year-old woman with severe dysphagia as a result of squamous cell carcinoma. Because of the proximal location of her tumor, we were concerned about airway compromise from stent place-
VOLUME 49, NO. 1, 1999
Letters to the Editor
r
Figure 1. View of carina demonstrates total occlusion of right mainstem bronchus (RMB) from posterior compression. Left mainstem bronchus (LMB) is partially compressed.
ment. Immediately before stenting, we placed a 20 mm diameter TTS balloon across the stricture. Despite maintenance of full dilating pressure for several minutes, the patient showed no sign of respiratory compromise. Thus, we deployed an 18 mm diameter stent (Covered Ultraflex; Microvasive, Watertown, Mass.) using endoscopic and fluoroscopic guidance, with good positioning of the entire stent below the upper esophageal sphincter. The patient initially showed no sign of respiratory impairment. However, shortly after the endoscope was removed, she developed stridor with drop in oxygen saturation. Auscultation disclosed absence of breath sounds in the right hemithorax. Bronchoscopy showed compression of the lower trachea with complete occlusion of the right mainstem bronchus (Fig. 1). The endoscope was reintroduced into the esophagus and the stent grasped at the proximal edge with alligator forceps (Fig. 2). By applying firm traction, the stent was removed through the mouth without significant trauma. The patient's stridor resolved and oxygen saturation normalized. She underwent radiation therapy with improvement in her dysphagia. We agree with the authors' recommendation that bronchoscopy be readily available at the time of stenting to detect airway compromise. Their timely suggestion helped us to identify tracheobronchial obstruction rapidly and avert a potentially life-threatening complication. However, we question the reliability of the response to dilator passage as a predictor of subsequent respiratory compromise. In our patient, tolerance to passage of a large-diameter dilator failed to predict airway obstruction induced by stent expansion. This test has been recommended by others,2 but its sensitivity remains unknown. We were able to remove the fully expanded Ultraflex stent once airway compromise was confirmed, thus avoiding the need for tracheobronchial intervention. The Wallstents used by the authors had sharp wire ends that
VOLUME 49, NO. 1, 1999
Figure 2. Proximal edge of expanded metal stent grasped with alligator forceps.
prevented such extraction. Because the Ultraflex stent can be removed soon after placement,3 it may be a more suitable choice for cases in which airway obstruction is likely to be a factor. Eric D. Libby, MD Rhody Fawaz, MD Ann M. Leana, MD Paul M. Hassoun, MD New England Medical Center Boston, Massachusetts REFERENCES 1. Dasgupta A, Jain P, Sandur S, Dolmatch BL, Geisinger MA,
Mehta AC. Airway complications of esophageal self-expandable metallic stent. Gastrointest Endosc 1998;47:532-5. 2. Nelson DB, Axelrad AM, Fleischer DE, Kozarek RA, Silvis SE, Freeman ML, et al. Silicone-covered Wallstent prototypes for palliation of malignant esophageal obstructions and digestive-respiratory fistulas. Gastrointest Endosc 1997;45:31-7. 3. Mallery S, Freeman ML. Removal of an incompletely expanded ultraflex esophageal stent. Gastrointest Endosc 1996;43:163-5.
Risk of self-expanding metal stents in patients with prior radiation or chemotherapy To the Editor: We read with interest the recent article by Siersema et aLl that compared self-expanding metal stents (SEMS) and latex prostheses for palliation of esophagogastric cancer. The authors are to be congratulated for a thoughtful study that again confirms the superiority of SEMS over rigid esophageal prostheses with regard to complications. However, we are concerned about the conclusion regarding the risk of these devices in patients previously treated with radiation and/or chemotherapy.
GASTROINTESTINAL ENDOSCOPY 137
cutaneous low molecular weight heparin as an outpatient as suggested by Dr. Rutgeerts, rather than hospitalization for intravenous heparin, is intriguing. Low molecular weight heparin in appropriate doses has been shown to be an effective treatment for acute deep venous thrombosis and pulmonary embolism. Therefore it may be reasonable to assume that its use in this case would satisfactorily prevent complications related to the mechanical valve. The third case deals with use of aspirin or NSAIDs before colonoscopy. These agents affect thromboxane A2-dependent platelet aggregation by means of inhibition of platelet cyclooxygenase. There are no control/ed data documenting a risk of increased bleeding after polypectomy. If the patient has taken aspirin up until 2 days before the colonoscopy, I agree with Dr. Wang and would perform the procedure as planned. There are practical problems with an absolute proscription against the use of aspirin or other anti-plateletlanti-inflammatory agents before colonoscopy. Some patients may absolutely require these agents for prophylaxis against stroke, treatment of severe arthritis, etc. Also, many prescription and over-the-counter products contain these compounds so it may not be possible always to provide patients with a complete list of medications to avoid. Furthermore, what is a colonoscopist to do with the patient with a pedunculated polyp in the descending colon who has already ingested a preparation solution, taken a day off work, come with a driver, and then is found to have taken aspirin 2 days before the procedure for a sporadic headache or back sprain? If desired by the individual colonoscopist, it is reasonable to make a good faith effort to ask patients to refrain from the use of these agents for several days before and after colonoscopy. However, if they are unable to do so for medical reasons or otherwise do not comply with the request, colonoscopy and polypectomy should be performed for the 1.5 cm polyp in the descending colon. For the fourth question, I agree that in the general population routine performances of blood tests (CSC, PT/PTT) before polypectomy to detect a potential coagulation defect are unnecessary. However, Dr. Llorens is correct in stating that a good clinical history before polypectomy is essential. Patients with known or suspected chronic liver disease or a personal or family history of excessive bleeding after surgery, tooth extraction, lacerations, or other trauma should undergo screening laboratory tests including CSC with platelet count, PT/PTI, bleeding time, and fibrinogen levels before endoscopic polypectomy. The American Society for Gastrointestinal Endoscopy will soon distribute a document from its Standards of
136
GASTROINTESTINAL ENDOSCOPY
Practice Committee entitled "Guideline on the Management of Anticoagulation and Antiplatelet Therapy for Endoscopic Procedures" (published in the December 1998 issue of Gastrointestinal Endoscopy). The reader is referred to this document for further discussion and references related to this topic. MD Cleveland, Ohio
GREGORY ZUCCARO, JR.,
Editor's comment. The patient with a primary coagulation disorder may begin bleeding several days after polypectomy, as can the patient who is re-started on Coumadin. A warning must be given to the patient as to this possibility. I suggest that they remain close to the medical center for at least 1 week post-polypectomy. The use of low molecular weight heparin for anticoagulation substitution for warfarin has not been published, but Dr. Rutgeerts, who is always a cautious and careful investigator, raises an interesting point. I do ask that aspirin be discontinued 1 week before colonoscopy, but still remove polyps if they have not complied with that request. Routine screening blood tests are unnecessary before polypectomy unless there is a historic suspicion of a bleeding tendency. f use endoclips to further ensure hemostasis postpolypectomy in patients with a known hematologic bleeding diathesis.
Airway complication of expandable stents To the Editor: Dasgupta et al. l report 2 cases in which placement of an expandable stent in the esophagus was complicated by respiratory compromise. Diagnosis was confirmed by bronchoscopy, but because these particular stents (Wallstent; Schneider, Plymouth, Minn.l could not be removed after placement, the patients required tracheobronchial stenting or laser therapy to maintain airway patency. The authors recommend performing bronchoscopy to detect airway compromise during stent deployment; alternatively they suggest passage of a large dilator with observation before stent placement. We recently experienced a similar airway problem while stenting a malignant stricture of the upper esophagus. The patient was an SO-year-old woman with severe dysphagia as a result of squamous cell carcinoma. Because of the proximal location of her tumor, we were concerned about airway compromise from stent place-
VOLUME 49, NO. 1, 1999
Letters to the Editor
r
Figure 1. View of carina demonstrates total occlusion of right mainstem bronchus (RMB) from posterior compression. Left mainstem bronchus (LMB) is partially compressed.
ment. Immediately before stenting, we placed a 20 mm diameter TTS balloon across the stricture. Despite maintenance of full dilating pressure for several minutes, the patient showed no sign of respiratory compromise. Thus, we deployed an 18 mm diameter stent (Covered Ultraflex; Microvasive, Watertown, Mass.) using endoscopic and fluoroscopic guidance, with good positioning of the entire stent below the upper esophageal sphincter. The patient initially showed no sign of respiratory impairment. However, shortly after the endoscope was removed, she developed stridor with drop in oxygen saturation. Auscultation disclosed absence of breath sounds in the right hemithorax. Bronchoscopy showed compression of the lower trachea with complete occlusion of the right mainstem bronchus (Fig. 1). The endoscope was reintroduced into the esophagus and the stent grasped at the proximal edge with alligator forceps (Fig. 2). By applying firm traction, the stent was removed through the mouth without significant trauma. The patient's stridor resolved and oxygen saturation normalized. She underwent radiation therapy with improvement in her dysphagia. We agree with the authors' recommendation that bronchoscopy be readily available at the time of stenting to detect airway compromise. Their timely suggestion helped us to identify tracheobronchial obstruction rapidly and avert a potentially life-threatening complication. However, we question the reliability of the response to dilator passage as a predictor of subsequent respiratory compromise. In our patient, tolerance to passage of a large-diameter dilator failed to predict airway obstruction induced by stent expansion. This test has been recommended by others,2 but its sensitivity remains unknown. We were able to remove the fully expanded Ultraflex stent once airway compromise was confirmed, thus avoiding the need for tracheobronchial intervention. The Wallstents used by the authors had sharp wire ends that
VOLUME 49, NO. 1, 1999
Figure 2. Proximal edge of expanded metal stent grasped with alligator forceps.
prevented such extraction. Because the Ultraflex stent can be removed soon after placement,3 it may be a more suitable choice for cases in which airway obstruction is likely to be a factor. Eric D. Libby, MD Rhody Fawaz, MD Ann M. Leana, MD Paul M. Hassoun, MD New England Medical Center Boston, Massachusetts REFERENCES 1. Dasgupta A, Jain P, Sandur S, Dolmatch BL, Geisinger MA,
Mehta AC. Airway complications of esophageal self-expandable metallic stent. Gastrointest Endosc 1998;47:532-5. 2. Nelson DB, Axelrad AM, Fleischer DE, Kozarek RA, Silvis SE, Freeman ML, et al. Silicone-covered Wallstent prototypes for palliation of malignant esophageal obstructions and digestive-respiratory fistulas. Gastrointest Endosc 1997;45:31-7. 3. Mallery S, Freeman ML. Removal of an incompletely expanded ultraflex esophageal stent. Gastrointest Endosc 1996;43:163-5.
Risk of self-expanding metal stents in patients with prior radiation or chemotherapy To the Editor: We read with interest the recent article by Siersema et aLl that compared self-expanding metal stents (SEMS) and latex prostheses for palliation of esophagogastric cancer. The authors are to be congratulated for a thoughtful study that again confirms the superiority of SEMS over rigid esophageal prostheses with regard to complications. However, we are concerned about the conclusion regarding the risk of these devices in patients previously treated with radiation and/or chemotherapy.
GASTROINTESTINAL ENDOSCOPY 137