Volume 25
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Number 11
’
November
’
2014
2. Hiraki T, Gobara H, Fujiwara H, et al. Lung cancer ablation: complications. Semin Intervent Radiol 2013; 30:169–175. 3. Günther RW. Percutaneous interventions in the thorax. Seventh annual Charles Dotter Memorial Lecture. J Vasc Interv Radiol 1992; 3:379–390. 4. Hiraki T, Gobara H, Shibamoto K, et al. Technique for creation of artificial pneumothorax for pain relief during radiofrequency ablation of peripheral lung tumors: report of seven cases. J Vasc Interv Radiol 2011; 22: 503–536.
Extraluminal Left Brachiocephalic Vein Superior Vena Cava (SVC) Confluence Reconstruction Using a Radiofrequency Wire to Treat SVC Syndrome
1837
targeted via oblique fluoroscopic images (Fig 1). RF wire contact with the bare metal stent was confirmed with the “metal contact alarm” on the RF wire control unit. A combination of a curved RF wire and a modified 4-F mini-pigtail catheter were used to achieve the desired acute angle to direct the RF wire parallel and in close proximity to the stent (Fig 2). Short bursts of RF energy and intermittent oblique fluoroscopic images were used to advance the RF wire parallel but external to the occluded right BCV/SVC stent with use of the “bounce technique.” This technique relies on an initial burst of RF energy, allowing for incremental wire advancement before the generator shuts off as a result of metal contact. Because of the craniocaudal orientation of the
From: Gajan Sivananthan, MD David W. Allen, MD Neil J. Halin, DO Department of Radiology Tufts Medical Center 800 Washington St. Boston, MA 02111
Editor: The technique of intraluminal crossing of a chronic central venous occlusion by using a radiofrequency (RF) wire has been previously described (1,2). In the present report, we describe a variation of this technique that uses an RF wire (Baylis, Montreal, Quebec, Canada) and a VIABAHN stent (W.L. Gore and Associates, Flagstaff, Arizona) to create a channel outside of an existing right brachiocephalic vein (BCV)/ superior vena cava (SVC) stent crossing an occluded left BCV. This report met the criteria for institutional review board exemption. A 42-year-old woman with chronic central venous catheter use as a result of poor peripheral intravenous access was referred to our vascular center for SVC syndrome (evidenced by inability to lie flat and facial and upper-extremity swelling) and a nonfunctioning right internal jugular vein port used for hydration during frequent diabetic ketoacidosis admissions. The port was placed at an outside institution 2 weeks earlier during a right BCV/SVC recanalization procedure that used a bare metal stent that crossed an occluded left BCV. Under general anesthesia, a 7-F, 30-cm Flexor sheath (Cook, Bloomington, Indiana) was advanced through a left basilic vein with the tip positioned in the left subclavian vein. A ZIPwire (Boston Scientific, Natick, Massachusetts) was advanced within 1 cm of the right BCV/SVC stent until it would not advance further. A 301 curved V2 RF wire (Baylis) set to 2 seconds of pulse energy was then advanced through a 4-F, 65-cm straight Slip-Cath catheter (Cook), with the right BCV/SVC stent
None of the authors have identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2014.06.031
Figure 1. A 301 curved V2 RF wire (black arrow) is advanced through a 5-F straight Slip-Cath catheter (white arrow) targeting the right BCV/SVC stent (arrowhead).
Figure 2. The 301 curved V2 RF wire (black arrow) is advanced parallel to the stent (arrowhead) by using the trajectory allowed by the modified pigtail catheter (white arrow).
1838
’
Letters to the Editor
RF wire, it was unlikely to enter the existing stent without contacting metal and shutting off. With a 20mm GooseNeck snare (ev3, Plymouth, Minnesota)— positioned in the SVC through a right common femoral vein access—as a target, the RF wire was directed into the SVC caudal to the occluded stent. The RF wire was then snared, pulled through the right common femoral access, and exchanged for an exchange-length Amplatz extra-stiff guide wire (Cook; Fig 3). The port catheter was exchanged for a 12-F, 40-cm Flexor sheath through a venotomy in the neck. Chemical thrombolysis of the right BCV in-stent thrombosis was performed with 4 mg tissue plasminogen activator administered with a Squirt fluid dispensing system (Merit Medical, South Jordan, Utah) and a SpeedLyser catheter (AngioDynamics, Latham, New York), with a dwell time of approximately 20 minutes. Rheolytic thrombectomy with an AngioJet device (Medrad, Indianola, Pennsylvania) was limited by symptomatic bradycardia. Predilation of the left BCV and SVC was performed with an 8-mm balloon to allow the 12-F, 80-cm Flexor sheath placed via the right common femoral vein to cross the occlusion for subsequent stent-graft placement. VIABAHN stents (10 mm 5 cm and 10 mm 10 cm) were deployed in the right and left BCVs, respectively, and simultaneously dilated to 10 mm. Completion venograms showed patent stents (Fig 4). Anticoagulation therapy with enoxaparin sodium and then warfarin was initiated in view of the patient’s
Figure 3. The RF wire (black arrow) is snared (white arrow) after entering the SVC caudal to the occlusion.
Sivananthan et al
’
JVIR
Figure 4. Completion venograms of right (a) and left (b) BCVs.
history of recurrent SVC thrombosis. Symptoms completely resolved at 1-month follow-up, with no evidence of facial or upper-extremity swelling. There is an increasing body of evidence to support the use of RF wire technology to treat central venous occlusions (1,2). These techniques use fluoroscopic triangulation to maintain an intravascular course. The technique described here differs from those in previous reports by creating an extraluminal conduit for venous flow. Three key stages are required to perform this procedure safely. First, careful triangulation must be used when crossing the mediastinum with the RF wire to avoid perforating arteries or the trachea. In the present case, we passed these structures with a hydrophilic guide wire. Second, the RF wire must be within close proximity to the stent before directing caudally. This is confirmed via the metal contact error message. Finally, the extraluminal tract must be within close proximity to the existing stent by directing the RF wire caudally and slightly toward the stent, allowing a relatively safe path immediately parallel to the stent. Despite careful planning and diligence, risks associated with the use of this technique include pericardial perforation, tamponade, mediastinal hemorrhage, and death. The likelihood of these complications is unknown and should be weighed against the potential benefits. In the present case, given the patient’s young age, long history of diabetes, and chronic vascular access use, the likelihood of her requiring vascular access and having limited options in the future was believed to be high.
Volume 25
’
Number 11
’
November
’
2014
For these reasons, preservation of left arm access was prioritized. Right BCV/SVC thrombolysis alone may have relieved her symptoms, but would have sacrificed left-sided access in the future, especially because we planned to perform salvage on the right side with a covered stent. Recanalization of the left BCV with stent placement through the interstices of the existing 10-mm right BCV/SVC stent would limit the sizes of the right and left BCV stents to 7 mm. The small caliber of the stents and the high likelihood of central venous catheters traversing the stents in the future would limit patency.
REFERENCES 1. Iafrati M, Maloney S, Halin N. Radiofrequency thermal wire is a useful adjunct to treat chronic central venous occlusion. J Vasc Surg 2012; 55:603–606. 2. Guimares M, Schonholz C, Hannegan C, Anderson MB, Shi J, Shelby B Jr. Radiofrequency wire for the recanalization of central vein occlusion that have failed conventional endovascular techniques. J Vasc Interv Radiol 2012; 23:1016–1021.
Re: “Microwave Ablation of Pulmonary Metastases Associated with Perioperative Takotsubo Cardiomyopathy” From: John E. Madias, MD Icahn School of Medicine at Mount Sinai New York, New York; and Division of Cardiology Elmhurst Hospital Center 79-01 Broadway Elmhurst, NY 11373
Editor: The article by Best et al (1) in the July 2014 issue of the Journal of Vascular and Interventional Radiology about a patient who experienced Takotsubo syndrome (TTS) in the setting of the first of two microwave ablations of pulmonary metastases to a previously surgically excised primary retroperitoneal leiomyosarcoma underscores the vagaries of ascribing cause to various potential triggers for the emergence of TTS. Indeed, in this case, one could consider any of the following as triggers: one’s state of mind dealing with cancer, potential paraneoplastic influences, anesthesia, metaraminol (a potent sympathomimetic amine and α1-adrenergic receptor agonist with some β-effects), and possible “remote” stimulation of the cardiac sympathetic nerves by the microwave ablation antenna. Should all patients with cancer be treated perioperatively with β-blockers? The top electrocardiogram (ECG) of figure 2 (1) reveals diffuse low voltage, with some restoration of the QRS amplitude in The author has not identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2014.07.021
1839
the two subsequent ECGs, in keeping with a recently reported diagnostic insight for TTS (2). I wonder whether comparison of this first ECG versus previous ECGs from this patient could have alerted the physicians that they were dealing with TTS, and even obviated an unnecessary urgent coronary angiogram.
REFERENCES 1. Best L, Seddon B, Woldman S, Lyon A, Illing R. Microwave ablation of pulmonary metastases associated with perioperative takotsubo cardiomyopathy. J Vasc Interv Radiol 2014; 25:1139–1141. 2. Madias JE. Transient attenuation of the amplitude of the QRS complexes in the diagnosis of Takotsubo syndrome. Eur Heart J Acute Cardiovasc Care 2014; 3:28–36.
In Reply: We would like to thank the author for his comment on our article (1,2). Takotsubo cardiomyopathy (TCM) has multiple triggers ranging from cancer to bereavement. We agree that it is helpful to differentiate between triggers that may be vaguely ascribed to individual patients because some triggers carry a higher risk for cardiac complications (eg, physical triggers) and because the triggers may provide insights into the underlying mechanism and the likelihood of recurrence. Although the author raises the provocative suggestion that patients with cancer undergoing surgical procedures may benefit from prophylactic beta blockers, the frequency of this type of complication is rare compared with the frequency of cancer and required interventions. To date, there is no evidence to support prophylactic beta-blocker therapy in all patients, but an argument could be made for a patient with a previous history of Takotsubo syndrome having a formal cardiology assessment before any future surgical procedure to discuss the potential use of prophylactic beta blockers during the procedure. The second issue raised is the potential to identify individuals with TCM without the need for invasive coronary angiography. The study by Madias (3) provides a possible diagnostic criterion for TCM, and in our case this may have expedited the diagnosis. Numerous noninvasive parameters, including biomarker profile, findings on electrocardiogram, and segmental distribution of regional wall motion abnormalities, may aid differentiation at initial clinical presentation between acute TCM and acute myocardial infarction secondary to acute coronary artery obstruction. However, none of these parameters provide sufficient specificity to exclude acute coronary occlusion. In the context of new cardiac chest pain, ST-segment elevation, and a stressful trigger, ST-segment elevation myocardial infarction is the most important diagnosis to confirm or exclude, and there is no evidence to date that withholding invasive diagnostic angiography is safe and should be recommended. We support the suggestion that more research is required in this area to identify a more sensitive and specific
’
Number 11
’
November
’
2014
2. Hiraki T, Gobara H, Fujiwara H, et al. Lung cancer ablation: complications. Semin Intervent Radiol 2013; 30:169–175. 3. Günther RW. Percutaneous interventions in the thorax. Seventh annual Charles Dotter Memorial Lecture. J Vasc Interv Radiol 1992; 3:379–390. 4. Hiraki T, Gobara H, Shibamoto K, et al. Technique for creation of artificial pneumothorax for pain relief during radiofrequency ablation of peripheral lung tumors: report of seven cases. J Vasc Interv Radiol 2011; 22: 503–536.
Extraluminal Left Brachiocephalic Vein Superior Vena Cava (SVC) Confluence Reconstruction Using a Radiofrequency Wire to Treat SVC Syndrome
1837
targeted via oblique fluoroscopic images (Fig 1). RF wire contact with the bare metal stent was confirmed with the “metal contact alarm” on the RF wire control unit. A combination of a curved RF wire and a modified 4-F mini-pigtail catheter were used to achieve the desired acute angle to direct the RF wire parallel and in close proximity to the stent (Fig 2). Short bursts of RF energy and intermittent oblique fluoroscopic images were used to advance the RF wire parallel but external to the occluded right BCV/SVC stent with use of the “bounce technique.” This technique relies on an initial burst of RF energy, allowing for incremental wire advancement before the generator shuts off as a result of metal contact. Because of the craniocaudal orientation of the
From: Gajan Sivananthan, MD David W. Allen, MD Neil J. Halin, DO Department of Radiology Tufts Medical Center 800 Washington St. Boston, MA 02111
Editor: The technique of intraluminal crossing of a chronic central venous occlusion by using a radiofrequency (RF) wire has been previously described (1,2). In the present report, we describe a variation of this technique that uses an RF wire (Baylis, Montreal, Quebec, Canada) and a VIABAHN stent (W.L. Gore and Associates, Flagstaff, Arizona) to create a channel outside of an existing right brachiocephalic vein (BCV)/ superior vena cava (SVC) stent crossing an occluded left BCV. This report met the criteria for institutional review board exemption. A 42-year-old woman with chronic central venous catheter use as a result of poor peripheral intravenous access was referred to our vascular center for SVC syndrome (evidenced by inability to lie flat and facial and upper-extremity swelling) and a nonfunctioning right internal jugular vein port used for hydration during frequent diabetic ketoacidosis admissions. The port was placed at an outside institution 2 weeks earlier during a right BCV/SVC recanalization procedure that used a bare metal stent that crossed an occluded left BCV. Under general anesthesia, a 7-F, 30-cm Flexor sheath (Cook, Bloomington, Indiana) was advanced through a left basilic vein with the tip positioned in the left subclavian vein. A ZIPwire (Boston Scientific, Natick, Massachusetts) was advanced within 1 cm of the right BCV/SVC stent until it would not advance further. A 301 curved V2 RF wire (Baylis) set to 2 seconds of pulse energy was then advanced through a 4-F, 65-cm straight Slip-Cath catheter (Cook), with the right BCV/SVC stent
None of the authors have identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2014.06.031
Figure 1. A 301 curved V2 RF wire (black arrow) is advanced through a 5-F straight Slip-Cath catheter (white arrow) targeting the right BCV/SVC stent (arrowhead).
Figure 2. The 301 curved V2 RF wire (black arrow) is advanced parallel to the stent (arrowhead) by using the trajectory allowed by the modified pigtail catheter (white arrow).
1838
’
Letters to the Editor
RF wire, it was unlikely to enter the existing stent without contacting metal and shutting off. With a 20mm GooseNeck snare (ev3, Plymouth, Minnesota)— positioned in the SVC through a right common femoral vein access—as a target, the RF wire was directed into the SVC caudal to the occluded stent. The RF wire was then snared, pulled through the right common femoral access, and exchanged for an exchange-length Amplatz extra-stiff guide wire (Cook; Fig 3). The port catheter was exchanged for a 12-F, 40-cm Flexor sheath through a venotomy in the neck. Chemical thrombolysis of the right BCV in-stent thrombosis was performed with 4 mg tissue plasminogen activator administered with a Squirt fluid dispensing system (Merit Medical, South Jordan, Utah) and a SpeedLyser catheter (AngioDynamics, Latham, New York), with a dwell time of approximately 20 minutes. Rheolytic thrombectomy with an AngioJet device (Medrad, Indianola, Pennsylvania) was limited by symptomatic bradycardia. Predilation of the left BCV and SVC was performed with an 8-mm balloon to allow the 12-F, 80-cm Flexor sheath placed via the right common femoral vein to cross the occlusion for subsequent stent-graft placement. VIABAHN stents (10 mm 5 cm and 10 mm 10 cm) were deployed in the right and left BCVs, respectively, and simultaneously dilated to 10 mm. Completion venograms showed patent stents (Fig 4). Anticoagulation therapy with enoxaparin sodium and then warfarin was initiated in view of the patient’s
Figure 3. The RF wire (black arrow) is snared (white arrow) after entering the SVC caudal to the occlusion.
Sivananthan et al
’
JVIR
Figure 4. Completion venograms of right (a) and left (b) BCVs.
history of recurrent SVC thrombosis. Symptoms completely resolved at 1-month follow-up, with no evidence of facial or upper-extremity swelling. There is an increasing body of evidence to support the use of RF wire technology to treat central venous occlusions (1,2). These techniques use fluoroscopic triangulation to maintain an intravascular course. The technique described here differs from those in previous reports by creating an extraluminal conduit for venous flow. Three key stages are required to perform this procedure safely. First, careful triangulation must be used when crossing the mediastinum with the RF wire to avoid perforating arteries or the trachea. In the present case, we passed these structures with a hydrophilic guide wire. Second, the RF wire must be within close proximity to the stent before directing caudally. This is confirmed via the metal contact error message. Finally, the extraluminal tract must be within close proximity to the existing stent by directing the RF wire caudally and slightly toward the stent, allowing a relatively safe path immediately parallel to the stent. Despite careful planning and diligence, risks associated with the use of this technique include pericardial perforation, tamponade, mediastinal hemorrhage, and death. The likelihood of these complications is unknown and should be weighed against the potential benefits. In the present case, given the patient’s young age, long history of diabetes, and chronic vascular access use, the likelihood of her requiring vascular access and having limited options in the future was believed to be high.
Volume 25
’
Number 11
’
November
’
2014
For these reasons, preservation of left arm access was prioritized. Right BCV/SVC thrombolysis alone may have relieved her symptoms, but would have sacrificed left-sided access in the future, especially because we planned to perform salvage on the right side with a covered stent. Recanalization of the left BCV with stent placement through the interstices of the existing 10-mm right BCV/SVC stent would limit the sizes of the right and left BCV stents to 7 mm. The small caliber of the stents and the high likelihood of central venous catheters traversing the stents in the future would limit patency.
REFERENCES 1. Iafrati M, Maloney S, Halin N. Radiofrequency thermal wire is a useful adjunct to treat chronic central venous occlusion. J Vasc Surg 2012; 55:603–606. 2. Guimares M, Schonholz C, Hannegan C, Anderson MB, Shi J, Shelby B Jr. Radiofrequency wire for the recanalization of central vein occlusion that have failed conventional endovascular techniques. J Vasc Interv Radiol 2012; 23:1016–1021.
Re: “Microwave Ablation of Pulmonary Metastases Associated with Perioperative Takotsubo Cardiomyopathy” From: John E. Madias, MD Icahn School of Medicine at Mount Sinai New York, New York; and Division of Cardiology Elmhurst Hospital Center 79-01 Broadway Elmhurst, NY 11373
Editor: The article by Best et al (1) in the July 2014 issue of the Journal of Vascular and Interventional Radiology about a patient who experienced Takotsubo syndrome (TTS) in the setting of the first of two microwave ablations of pulmonary metastases to a previously surgically excised primary retroperitoneal leiomyosarcoma underscores the vagaries of ascribing cause to various potential triggers for the emergence of TTS. Indeed, in this case, one could consider any of the following as triggers: one’s state of mind dealing with cancer, potential paraneoplastic influences, anesthesia, metaraminol (a potent sympathomimetic amine and α1-adrenergic receptor agonist with some β-effects), and possible “remote” stimulation of the cardiac sympathetic nerves by the microwave ablation antenna. Should all patients with cancer be treated perioperatively with β-blockers? The top electrocardiogram (ECG) of figure 2 (1) reveals diffuse low voltage, with some restoration of the QRS amplitude in The author has not identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2014.07.021
1839
the two subsequent ECGs, in keeping with a recently reported diagnostic insight for TTS (2). I wonder whether comparison of this first ECG versus previous ECGs from this patient could have alerted the physicians that they were dealing with TTS, and even obviated an unnecessary urgent coronary angiogram.
REFERENCES 1. Best L, Seddon B, Woldman S, Lyon A, Illing R. Microwave ablation of pulmonary metastases associated with perioperative takotsubo cardiomyopathy. J Vasc Interv Radiol 2014; 25:1139–1141. 2. Madias JE. Transient attenuation of the amplitude of the QRS complexes in the diagnosis of Takotsubo syndrome. Eur Heart J Acute Cardiovasc Care 2014; 3:28–36.
In Reply: We would like to thank the author for his comment on our article (1,2). Takotsubo cardiomyopathy (TCM) has multiple triggers ranging from cancer to bereavement. We agree that it is helpful to differentiate between triggers that may be vaguely ascribed to individual patients because some triggers carry a higher risk for cardiac complications (eg, physical triggers) and because the triggers may provide insights into the underlying mechanism and the likelihood of recurrence. Although the author raises the provocative suggestion that patients with cancer undergoing surgical procedures may benefit from prophylactic beta blockers, the frequency of this type of complication is rare compared with the frequency of cancer and required interventions. To date, there is no evidence to support prophylactic beta-blocker therapy in all patients, but an argument could be made for a patient with a previous history of Takotsubo syndrome having a formal cardiology assessment before any future surgical procedure to discuss the potential use of prophylactic beta blockers during the procedure. The second issue raised is the potential to identify individuals with TCM without the need for invasive coronary angiography. The study by Madias (3) provides a possible diagnostic criterion for TCM, and in our case this may have expedited the diagnosis. Numerous noninvasive parameters, including biomarker profile, findings on electrocardiogram, and segmental distribution of regional wall motion abnormalities, may aid differentiation at initial clinical presentation between acute TCM and acute myocardial infarction secondary to acute coronary artery obstruction. However, none of these parameters provide sufficient specificity to exclude acute coronary occlusion. In the context of new cardiac chest pain, ST-segment elevation, and a stressful trigger, ST-segment elevation myocardial infarction is the most important diagnosis to confirm or exclude, and there is no evidence to date that withholding invasive diagnostic angiography is safe and should be recommended. We support the suggestion that more research is required in this area to identify a more sensitive and specific
