Small intestine capsule endoscopy in magnetic suspended axial left ventricular assist device patient
http://www.100md.com
《血管的通路杂志》
a Department of Cardio-Thoracic Surgery ‘A. De Gasperis’, Niguarda Ca' Granda Hospital, Piazza Ospedale Maggiore 3, 20162 Milan, Italy
b Department of Gastroenterology and Digestive Endoscopy, Busto Arsizio Hospital, Milan, Italy
Abstract
A 45-year-old male with dilatative cardiomyopathy was supported with an Incor (Berlin-Heart AG) axial flow magnetically levitated bearings pump. Due to constant anemization in late follow-up, gastrointestinal bleeding was suspected and a PillCamTM Capsule Endoscopy (Given Imaging) was performed. No interference between the devices was detected and full small bowel visualization was achieved.
Key Words: Left ventricular assist device; Gastrointestinal bleeding; Capsule endoscopy
1. Introduction
Gastrointestinal bleeding is not uncommon in critically ill patients requiring intensive support and LVAD therapy, and seems to happen more frequently when continuous axial flow pumps are implanted. In a recent paper Letsou and co-workers [1] reported obscure GI bleeding in patients supported with the Jarvik 2000 LVAD. They suggest that hypoperfusion of the bowel which results from the lowered pulse pressure leads to vascular dilation and angiodysplasia. This is consistent with other observations in literature [2,3]. As obscure GI bleeding in such patients is difficult to manage and often requires laparotomy and blind bowel resection, aggressive localisation of the bleeding source by endoscopic and radiologic means is mandatory. Capsule endoscopy (CE) is a new promising technology particularly useful in evaluating small bowel diseases. We report our experience with CE in a patient supported with the Incor LVAD.
2. Berlin Heart Incor LVAD
The Incor (Berlin Heart AG, Berlin) is a new axial flow pump that differs considerably from other available systems (Fig. 1A). The impeller is held by a magnetic bearing and has no physical contact with other parts, and can rotate at speeds of up to 10,000 rpm. This corresponds to a potential blood flow of 7 l/min (against 150 mmHg). Silicone inflow and outflow cannulas are attached to the pump chamber with connector systems that are easy to re-open. The drive-line of the device is connected to an externally wearable controller and to two battery packs.
3. Capsule endoscopy
Wireless video capsule endoscopy (CE) is a new advanced technology that enables endoscopic evaluation of the entire small intestinal mucosa [4,5]. The capsule endoscope is ingested after an 8-h fast and is propelled through the small intestine by peristalsis. The capsule is composed of a lens, a light source, a complementary metal-oxide semiconductor (CMOS) chip, a battery, and a transmitter (Fig. 1B). The capsule endoscope transmits acquired images via a digital radiofrequency communication channel to the data recorder unit located outside the body.
4. Case report
A 45-year-old man was admitted to our department for congestive heart failure, low output syndrome and pulmonary oedema. He suffered from dilatative cardiomyopathy established in 1998, with EF of 21%. He had no history of gastrointestinal (GI) bleeding. In early 2004 he was implanted with biventricular pacing and an implantable cardiac defibrillator (ICD) without clinical improvement after cardiac resynchronisation therapy. During the same year he suffered from several heart failure episodes, and was admitted for a period of inotropic support, with partial clinical response. After admission the patient was supported with inotrops and IABP with clinical stabilization, and after clinical screening he was listed for heart transplant. As clinical status worsened rapidly with initial signs of hepatic dysfunction, he was implanted with the Incor (Berlin-Heart AG) axial flow magnetically levitated bearings LVAD. The device was implanted via a median sternotomy with cardiopulmonary bypass. Blood loss was minimal. After weaning from cardiopulmonary bypass, LVAD support was initiated at a flow rate of 4.8 l/min. Extubation was performed expeditiously, and the immediate postoperative recovery was otherwise uneventful. However, during the subsequent course of LVAD support, multiple episodes of GI bleeding developed. Bleeding was first diagnosed on postoperative day (POD) 45 on the basis of heme-positive stools and a drop in haemoglobin concentration. On POD 60 melena developed and the haemoglobin concentration fell to 7.2 g/dl. Numerous blood transfusions were necessary as well as selective intra-arterial vasopressin infusion. Extensive evaluation with endoscopy showed no active bleeding lesions in the upper digestive tract nor in the colon. Nuclear RBC imaging revealed poussè bleeding origin in the small intestine. Otherwise, catheterisation of superior and inferior mesenteric artery failed to reveal active bleeding lesions or arteriovenous malformations of the small bowel (Fig. 2A–B). Low haemoglobin concentrations, ranging from 8.2 g/dl to 10.9 g/dl, necessitated multiple blood transfusions. On POD 77 haemoglobin concentration fell again to 6.8 g/dl and capsule endoscopy of the entire digestive tract was then performed on POD 108, failing to reveal any active bleeding lesions (Fig. 2C–D). According to the Berlin heart experience, antiplatelet therapy was then stopped, and anticoagulation regimen was managed in order to reach a target INR of 2; bleeding seemed to be solved and haemoglobin concentration increased to 11 g/dl. No GI bleeding occurred during the remaining period of LVAD support. After 185 days of support, successful orthotopic cardiac transplantation was performed. There has been no recurrence of GI bleeding after cardiac transplantation.
5. Discussion
Capsule endoscopy is a new technology that is used in the evaluation of certain GI disorders, especially obscure GI bleeding (OGIB) [6]. Electromagnetic devices may interfere with the function of implanted cardiac devices. The potential for radiofrequency ablation to interfere with the function of pacemakers has been previously established [7]. In that study, 12 out of 23 (52%) pacemakers malfunctioned and five of them had circuitry failure. Electromagnetic interference may also occur even when the source is not in direct contact with the device, such as is the case with digital cellular phones, electronic surveillance systems, and electrocautery devices [8]. There is a concern that CE may interfere with certain electromechanical devices. Previously, Leighton and co-workers evaluated the safety of CE in patients with cardiac pacemakers [9] and implantable cardiac defibrillators (ICD) [10]. CE appeared to be safe and was not associated with any significant adverse cardiac events. This is, to our knowledge, the first time in which CE was used in a patient supported with an LVAD. Besides, the magnetic-based technology of Incor LVAD may raise concerns about the potential interferences with the electromagnetic source generated by the CE. The international standard for the radiofrequency immunity of medical devices is guided by the 1993 revision of the International Electro-technical Commission (IEC) Standard IEC 60601-1-2. This standard sets a minimum immunity level of 3 volts per meter (V/m) in the 26–1,000 MHz frequency range. At the CE frequency range (434.09 MHz), LVADs require this degree of immunity. The lack of detectable alteration in the programmed parameters suggests that the ‘immunity threshold’ of the Incor LVAD was not breached by CE. We measured pump parameters such as the bearing power (0.4 W), the motor current (0.5 A) and the pump speed (7400 rpm) before and after the CE and found them unchanged. Besides, no alterations in haemodynamic were found during and after the procedure. Differential pressure signal and pump flow, which are calculated indirectly from the variations in the pump magnetic field, were unchanged during and after the procedure, suggesting that no interference between the two electromagnetic fields existed during endoscopy. The vector of radiofrequency transmission with CE is mostly within the abdomen and therefore away from the location of the LVAD, which is another important factor in reducing interference. Nevertheless, during oesophageal and gastric transit time, during which CE passes potentially closer to Incor LVAD, no interference in the pump and CE signals was detected.
6. Conclusion
CE in this experience resulted in usefully evaluating obscure GI bleeding. In particular we didn't find any interferences between the endoscope and the Incor LVAD. As obscure GI bleeding in such patients is difficult to manage and often requires laparotomy and blind bowel resection, aggressive localisation of the bleeding source by endoscopic and radiologic means is mandatory.
References
Letsou GV, Shah N, Gregoric ID, Mayers TJ, Delgado R, Frazier OH. Gastrointestinal bleeding from arteriovenous malformations in patients supported by the Jarvik 2000 axial-flow left ventricular assist device. J Heart Lung Transplant 2005; 24:105–109.
Boley SJ, Sammartano R, Adams A, DiBiase A, Kleinhaus S, Sprayregen S. On the nature and etiology of vascular ectasias of the colon. Gastroenterology 1977; 72:650–660.
Cappell MS, Lebwohl O. Cessation of recurrent bleeding from gastrointestinal angiodysplasias after aortic valve replacement. Ann Intern Med 1986; 105:55–57.
Iddan G, Meron G, Glukhovsky A, Swain P. Wireless capsule endoscopy. Nature 2000; 405:417.
Appleyard M, Glukhovsky A, Swain P. Wireless-capsule diagnostic endoscopy for recurrent small-bowel bleeding. N Engl J Med 2001; 344:232–233.
Yousfi M, Sharma VK, Leighton JA, Fleischer DE. Video capsule endoscopy for obscure gastrointestinal bleeding and iron deficiency anemia. Gastroenterology 2002; 122:4A18.
Hayes DL, Wang PJ, Reynolds DW, Estes M 3rd, Griffith JL, Steffens RA, Carlo GL, Findlay GK, Johnson CM. Interference with cardiac pacemakers by cellular telephones. N Engl J Med 1997; 336:1473–1479.
Dodinot B, Godenir JP, Costa AB. Electronic article surveillance: a possible danger for pacemaker patients. Pacing Clin Electrophysiol 1993; 16:46–53.
Leighton JA, Sharma VK, Srivathsan K, Heigh RI, McWane TL, Post JK, Robinson SR, Bazzell JL. Safety of capsule endoscopy in patients with pacemakers. Gastrointest Endosc 2004; 59:4567–569.
Leighton JA, Srivathsan K, Carey EJ, Sharma VK, Heigh RI, Post JK, Erickson PJ, Robinson SR, Bazzell JL, Fleischer DE. Safety of wireless capsule endoscopy in patients with implantable cardiac defibrillators. Am J Gastroenterol 2005; 100:1728–1731.(Andrea Garatti, Giuseppe )
b Department of Gastroenterology and Digestive Endoscopy, Busto Arsizio Hospital, Milan, Italy
Abstract
A 45-year-old male with dilatative cardiomyopathy was supported with an Incor (Berlin-Heart AG) axial flow magnetically levitated bearings pump. Due to constant anemization in late follow-up, gastrointestinal bleeding was suspected and a PillCamTM Capsule Endoscopy (Given Imaging) was performed. No interference between the devices was detected and full small bowel visualization was achieved.
Key Words: Left ventricular assist device; Gastrointestinal bleeding; Capsule endoscopy
1. Introduction
Gastrointestinal bleeding is not uncommon in critically ill patients requiring intensive support and LVAD therapy, and seems to happen more frequently when continuous axial flow pumps are implanted. In a recent paper Letsou and co-workers [1] reported obscure GI bleeding in patients supported with the Jarvik 2000 LVAD. They suggest that hypoperfusion of the bowel which results from the lowered pulse pressure leads to vascular dilation and angiodysplasia. This is consistent with other observations in literature [2,3]. As obscure GI bleeding in such patients is difficult to manage and often requires laparotomy and blind bowel resection, aggressive localisation of the bleeding source by endoscopic and radiologic means is mandatory. Capsule endoscopy (CE) is a new promising technology particularly useful in evaluating small bowel diseases. We report our experience with CE in a patient supported with the Incor LVAD.
2. Berlin Heart Incor LVAD
The Incor (Berlin Heart AG, Berlin) is a new axial flow pump that differs considerably from other available systems (Fig. 1A). The impeller is held by a magnetic bearing and has no physical contact with other parts, and can rotate at speeds of up to 10,000 rpm. This corresponds to a potential blood flow of 7 l/min (against 150 mmHg). Silicone inflow and outflow cannulas are attached to the pump chamber with connector systems that are easy to re-open. The drive-line of the device is connected to an externally wearable controller and to two battery packs.
3. Capsule endoscopy
Wireless video capsule endoscopy (CE) is a new advanced technology that enables endoscopic evaluation of the entire small intestinal mucosa [4,5]. The capsule endoscope is ingested after an 8-h fast and is propelled through the small intestine by peristalsis. The capsule is composed of a lens, a light source, a complementary metal-oxide semiconductor (CMOS) chip, a battery, and a transmitter (Fig. 1B). The capsule endoscope transmits acquired images via a digital radiofrequency communication channel to the data recorder unit located outside the body.
4. Case report
A 45-year-old man was admitted to our department for congestive heart failure, low output syndrome and pulmonary oedema. He suffered from dilatative cardiomyopathy established in 1998, with EF of 21%. He had no history of gastrointestinal (GI) bleeding. In early 2004 he was implanted with biventricular pacing and an implantable cardiac defibrillator (ICD) without clinical improvement after cardiac resynchronisation therapy. During the same year he suffered from several heart failure episodes, and was admitted for a period of inotropic support, with partial clinical response. After admission the patient was supported with inotrops and IABP with clinical stabilization, and after clinical screening he was listed for heart transplant. As clinical status worsened rapidly with initial signs of hepatic dysfunction, he was implanted with the Incor (Berlin-Heart AG) axial flow magnetically levitated bearings LVAD. The device was implanted via a median sternotomy with cardiopulmonary bypass. Blood loss was minimal. After weaning from cardiopulmonary bypass, LVAD support was initiated at a flow rate of 4.8 l/min. Extubation was performed expeditiously, and the immediate postoperative recovery was otherwise uneventful. However, during the subsequent course of LVAD support, multiple episodes of GI bleeding developed. Bleeding was first diagnosed on postoperative day (POD) 45 on the basis of heme-positive stools and a drop in haemoglobin concentration. On POD 60 melena developed and the haemoglobin concentration fell to 7.2 g/dl. Numerous blood transfusions were necessary as well as selective intra-arterial vasopressin infusion. Extensive evaluation with endoscopy showed no active bleeding lesions in the upper digestive tract nor in the colon. Nuclear RBC imaging revealed poussè bleeding origin in the small intestine. Otherwise, catheterisation of superior and inferior mesenteric artery failed to reveal active bleeding lesions or arteriovenous malformations of the small bowel (Fig. 2A–B). Low haemoglobin concentrations, ranging from 8.2 g/dl to 10.9 g/dl, necessitated multiple blood transfusions. On POD 77 haemoglobin concentration fell again to 6.8 g/dl and capsule endoscopy of the entire digestive tract was then performed on POD 108, failing to reveal any active bleeding lesions (Fig. 2C–D). According to the Berlin heart experience, antiplatelet therapy was then stopped, and anticoagulation regimen was managed in order to reach a target INR of 2; bleeding seemed to be solved and haemoglobin concentration increased to 11 g/dl. No GI bleeding occurred during the remaining period of LVAD support. After 185 days of support, successful orthotopic cardiac transplantation was performed. There has been no recurrence of GI bleeding after cardiac transplantation.
5. Discussion
Capsule endoscopy is a new technology that is used in the evaluation of certain GI disorders, especially obscure GI bleeding (OGIB) [6]. Electromagnetic devices may interfere with the function of implanted cardiac devices. The potential for radiofrequency ablation to interfere with the function of pacemakers has been previously established [7]. In that study, 12 out of 23 (52%) pacemakers malfunctioned and five of them had circuitry failure. Electromagnetic interference may also occur even when the source is not in direct contact with the device, such as is the case with digital cellular phones, electronic surveillance systems, and electrocautery devices [8]. There is a concern that CE may interfere with certain electromechanical devices. Previously, Leighton and co-workers evaluated the safety of CE in patients with cardiac pacemakers [9] and implantable cardiac defibrillators (ICD) [10]. CE appeared to be safe and was not associated with any significant adverse cardiac events. This is, to our knowledge, the first time in which CE was used in a patient supported with an LVAD. Besides, the magnetic-based technology of Incor LVAD may raise concerns about the potential interferences with the electromagnetic source generated by the CE. The international standard for the radiofrequency immunity of medical devices is guided by the 1993 revision of the International Electro-technical Commission (IEC) Standard IEC 60601-1-2. This standard sets a minimum immunity level of 3 volts per meter (V/m) in the 26–1,000 MHz frequency range. At the CE frequency range (434.09 MHz), LVADs require this degree of immunity. The lack of detectable alteration in the programmed parameters suggests that the ‘immunity threshold’ of the Incor LVAD was not breached by CE. We measured pump parameters such as the bearing power (0.4 W), the motor current (0.5 A) and the pump speed (7400 rpm) before and after the CE and found them unchanged. Besides, no alterations in haemodynamic were found during and after the procedure. Differential pressure signal and pump flow, which are calculated indirectly from the variations in the pump magnetic field, were unchanged during and after the procedure, suggesting that no interference between the two electromagnetic fields existed during endoscopy. The vector of radiofrequency transmission with CE is mostly within the abdomen and therefore away from the location of the LVAD, which is another important factor in reducing interference. Nevertheless, during oesophageal and gastric transit time, during which CE passes potentially closer to Incor LVAD, no interference in the pump and CE signals was detected.
6. Conclusion
CE in this experience resulted in usefully evaluating obscure GI bleeding. In particular we didn't find any interferences between the endoscope and the Incor LVAD. As obscure GI bleeding in such patients is difficult to manage and often requires laparotomy and blind bowel resection, aggressive localisation of the bleeding source by endoscopic and radiologic means is mandatory.
References
Letsou GV, Shah N, Gregoric ID, Mayers TJ, Delgado R, Frazier OH. Gastrointestinal bleeding from arteriovenous malformations in patients supported by the Jarvik 2000 axial-flow left ventricular assist device. J Heart Lung Transplant 2005; 24:105–109.
Boley SJ, Sammartano R, Adams A, DiBiase A, Kleinhaus S, Sprayregen S. On the nature and etiology of vascular ectasias of the colon. Gastroenterology 1977; 72:650–660.
Cappell MS, Lebwohl O. Cessation of recurrent bleeding from gastrointestinal angiodysplasias after aortic valve replacement. Ann Intern Med 1986; 105:55–57.
Iddan G, Meron G, Glukhovsky A, Swain P. Wireless capsule endoscopy. Nature 2000; 405:417.
Appleyard M, Glukhovsky A, Swain P. Wireless-capsule diagnostic endoscopy for recurrent small-bowel bleeding. N Engl J Med 2001; 344:232–233.
Yousfi M, Sharma VK, Leighton JA, Fleischer DE. Video capsule endoscopy for obscure gastrointestinal bleeding and iron deficiency anemia. Gastroenterology 2002; 122:4A18.
Hayes DL, Wang PJ, Reynolds DW, Estes M 3rd, Griffith JL, Steffens RA, Carlo GL, Findlay GK, Johnson CM. Interference with cardiac pacemakers by cellular telephones. N Engl J Med 1997; 336:1473–1479.
Dodinot B, Godenir JP, Costa AB. Electronic article surveillance: a possible danger for pacemaker patients. Pacing Clin Electrophysiol 1993; 16:46–53.
Leighton JA, Sharma VK, Srivathsan K, Heigh RI, McWane TL, Post JK, Robinson SR, Bazzell JL. Safety of capsule endoscopy in patients with pacemakers. Gastrointest Endosc 2004; 59:4567–569.
Leighton JA, Srivathsan K, Carey EJ, Sharma VK, Heigh RI, Post JK, Erickson PJ, Robinson SR, Bazzell JL, Fleischer DE. Safety of wireless capsule endoscopy in patients with implantable cardiac defibrillators. Am J Gastroenterol 2005; 100:1728–1731.(Andrea Garatti, Giuseppe )