Iatrogenic Acute Aortic Dissection During Cardioplegic Cannula Insertion Detected by Transesophageal Echocardiography

LETTERS TO THE EDITOR

A Word of Caution Regarding Transesophageal Echocardiography and Penetrating Chest Trauma

Neal Stuart Gerstein, MD Department of Anesthesiology and Critical Care Medicine University of New Mexico School of Medicine Albuquerque, NM

To the Editor: REFERENCES

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In their recent Case Conferenence, Stein et described the use of transesophageal echocardiography (TEE) to assist in the diagnosis and management of a stab wound to the left chest. I would like to proffer a word of caution regarding the use of TEE in a patient who recently had sustained a penetrating chest injury. A victim of multiple gunshot wounds to the chest was brought to our trauma center and immediately to the operating room. The patient was hemodynamically unstable on presentation and had not had any emergency room ultrasound evaluation. Hence, the decision was made to perform a comprehensive TEE examination after anesthesia induction. The TEE probe was inserted without difficulty, and a complete TEE examination was performed. The patient had large bilateral hemopneumothoraces and various abdominal injuries but no cardiac or pericardial injuries. However, the trauma surgeon noted that he visualized the TEE probe through a significant ragged-appearing esophageal laceration. It was hypothesized that one of the bullets had created an esophageal injury and that TEE probe insertion had turned a small injury into a more extensive linear laceration. The patient’s injuries were all managed successfully, but he required temporary division of his esophagus with the creation of a “spit” fistula. He later returned for reconnection of the proximal and distal esophageal segments. The literature is replete with cases and descriptions of esophageal injury secondary to the TEE probe.2-7 It has been reported that the greatest number of injuries to the esophagus caused by the TEE probe are in patients with occult esophageal pathology,8 as was certainly the issue in our patient. In a recent review of 154 patients with penetrating chest injuries because of terrorist-related explosions containing heavy shrapnel, there was only a single esophageal injury.9 A similar review of 207 patients with mediastinal penetrating injuries had no cases of esophageal injury.10 In a case series of 10 patients over an 11-year span with traumatic esophageal perforations, 7 were caused by gunshot wounds.11 However, it is unclear in this series whether the esophageal injury location was in the neck or chest. Although esophageal injury after penetrating chest trauma is uncommon, our case shows prudence should be exercised when using TEE during the management of penetrating chest injuries. The risk versus benefit of a comprehensive TEE examination should be considered carefully in the context of these trauma cases.

1. Stein E, Daigle S, Weiss SJ, et al: CASE 3—2011: Successful management of a complicated traumatic ventricular septal defect. J Cardiothorac Vasc Anesth 25:547-552, 2011 2. Omorphos S, Kotoulas C, Homer JJ, et al: Delayed repair of esophageal perforation due to transoesophageal echocardiography. Monaldi Arch Chest Dis 68:239-240, 2007 3. Nana AM, Stefanidis C, Chami JP, et al: Esophageal perforation by echoprobe during cardiac surgery: Treatment by endoscopic stenting. Ann Thorac Surg 75:1955-1957, 2003 4. Bossert T, Paxian M, Heise M, et al: Cervical esophageal perforation by transesophageal echocardiography probe detected during coronary artery bypass grafting. Clin Res Cardiol 98:278-279, 2009 5. Kallmeyer IJ, Collard CD, Fox JA, et al: The safety of intraoperative transesophageal echocardiography: A case series of 7200 cardiac surgical patients. Anesth Analg 92:1126-1130, 2001 6. Urbanowicz JH, Kernoff RS, Oppenheim G, et al: Transesophageal echocardiography and its potential for esophageal damage. Anesthesiology 72:40-43, 1990 7. Pong MW, Lin SM, Kao SC, et al: Unusual cause of esophageal perforation during intraoperative transesophageal echocardiography monitoring for cardiac surgery—A case report. Acta Anaesthesiol Sin 41:155-158, 2003 8. Kharasch ED, Sivarajan M: Gastroesophageal perforation after intraoperative transesophageal echocardiography. Anesthesiology 85: 426-428, 1996 9. Bala M, Shussman N, Rivkind AI, et al: The pattern of thoracic trauma after suicide terrorist bombing attacks. J Trauma 69:1022-1028, 2010 10. Burack JH, Kandil E, Sawas A, et al: Triage and outcome of patients with mediastinal penetrating trauma. Ann Thorac Surg 83:377382, 2007 11. Andrade-Alegre R: Surgical treatment of traumatic esophageal perforations: Analysis of 10 cases. Clinics (Sao Paulo) 60:375-380, 2005 doi:10.1053/j.jvca.2011.07.025

Iatrogenic Acute Aortic Dissection During Cardioplegic Cannula Insertion Detected by Transesophageal Echocardiography To the Editor: Iatrogenic acute aortic dissection (IAAD) is a rare but potentially lethal complication. Fortunately, the reported incidence of IAAD is low (approximately 0.16% to 0.35%),1 perhaps because of underreporting or underdetection (small or posteriorly located, precluding visual detection). The authors report a case of IAAD

Journal of Cardiothoracic and Vascular Anesthesia, Vol 26, No 1 (February), 2012: pp e3-e7

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Fig 1. Transesophageal echocardiograms. (A) Aortic short-axis view. A dissection flap (arrow) is seen in the ascending aorta. The small lumen is the false lumen and the larger lumen is the true lumen. (B) Midesophageal aortic long-axis view. Color Doppler comparison image shows a dissection flap (arrow) in the posterior wall of the ascending aorta. (Color version of figure is available online.)

with an intimal tear in the posterior wall of the ascending aorta during cardioplegic cannula insertion detected intraoperatively by transesophageal echocardiography (TEE). A 25-year-old man presented with complaints of cyanosis and dyspnea on exertion since childhood and was diagnosed to have tetralogy of Fallot. After providing consent, the patient was scheduled for an intracardiac repair. Anesthesia induction and intubation were uneventful. The baseline TEE confirmed the preoperative diagnosis. No other cardiac abnormalities were detected. After heparinization, cardiopulmonary bypass (CPB) was established. While on partial CPB, multiple attempts for cardioplegic cannula insertion were required. After cold cardioplegic arrest, intracardiac repair was performed and the patient came off CPB with normal hemodynamic parameters. The postoperative TEE (with the aortobicaval cannulae still in situ) showed a dissection flap in the posterior wall of the ascending aorta (Fig 1A, B). Its extension into the distal ascending aorta and the proximal arch could not be appreciated. A decision was made to locate the injury site, repair the defect, and examine any distal extension. CPB was reestablished and deep hypothermic circula-

LETTERS TO THE EDITOR

tory arrest was instituted at a nasopharyngeal temperature of 20°C. Thereafter, the cardioplegia cannula and the aortic cross-clamp were removed. After aortotomy, an intimal tear on the posterior wall of the ascending aorta opposite the cardioplegia cannula insertion site was observed. This tear was repaired with polytetrafluoroethylene (Bard Peripheral Vascular, Inc, Tempe, AZ), pledgeted, interrupted, polypropylene monofilament (Prolene; Ethicon, Inc, Somerville, NJ) sutures. The patient gradually was rewarmed, adequate hemostasis was achieved, and the patient was weaned successfully from CPB. The patient subsequently was transferred to the intensive care unit with an uneventful postoperative course. A postoperative magnetic resonance scan demonstrated a dissection flap extending from the ascending aorta to the distal arch, with all major branch arteries arising from the true lumen. No blood flow was noted through the false lumen. A follow-up scan showed the decreasing size of the false lumen with the presence of thrombus inside it. The patient was discharged from the hospital and is undergoing regular follow-up at the authors’ outpatient clinic. IAAD has a high morbidity and mortality. Still et al,1 in their review of 14,877 patients, detected IAAD in 24 patients, with a mortality of 20% when diagnosed intraoperatively and 50% when the diagnosis was delayed. Hwang et al2 reported IAAD in 0.29% of 3,421 adult patients undergoing cardiac surgery, with a mortality rate of 40%. Mortality rate was lower when routine intraoperative TEE was used and if the dissection did not extend beyond the aortic arch. The predisposing factors increasing the risk of IAAD include atherosclerotic aorta, longstanding hypertension, dilated thin-walled aorta, congenital connective tissue disorders, and cystic medial necrosis.1 However, nearly half of patients who developed IAAD were observed to have clinically normal aortas.1 The present patient was young and had no aortic disease as seen on baseline TEE. Asian race3 and tetralogy of Fallot4 were the only predisposing factors. IAAD can arise from the sites of aortic or antegrade cardioplegic cannulation, cross-clamp application, aortotomy, or a proximal venous anastomosis site.5,6 In the present case, the cardioplegic cannula insertion required multiple attempts on partial CPB, when systolic pressures were low and the aorta was supple in nature. During 1 of these attempts, the stylet of the cannula might have hit the posterior wall of the ascending aorta, resulting in an intimal injury that became apparent only after coming off CPB. The surgical management of IAAD depends on its location and extent. A tube graft interposition is required for extensive dissection.1,5 A conservative surgical approach with a pledgeted primary suture to reapproximate the injured intima is sufficient if the dissection is localized.7 Because the intimal tear was small and appeared to be localized, the authors repaired it from within the lumen using interrupted pledgeted sutures. The authors decided to perform deep hypothermic circulatory arrest, considering the possibility of the involvement of the arch of aorta because the TEE information was incomplete. Although TEE has good sensitivity of 98% and specificity of 95% in detecting aortic dissection,8 it has certain limitations. The TEE echocardiographic window becomes blind when interrogating the distal portion of the ascending aorta and the proximal aortic arch. These regions can be interrogated best by an epiaortic echocardiographic probe.9

LETTERS TO THE EDITOR

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To conclude, not only high systemic pressures but also low aortic pressure can be a risk factor for dissection during aortic cannulation. Cardioplegic cannula insertion ideally should be performed before going on partial CPB to decrease the risk of IAAD. Although a very simple and basic measure, it can prevent a disaster of major proportions. The postoperative interrogation of the aortic cannulation site should be performed as routine practice in every case. Parag Gharde, DM* Vikram Aggarwal, MD* Sandeep Chauhan, MD* Usha Kiran, MD* V. Devagourou, MCh† Departments of *Cardiac Anesthesia and †Cardiothoracic Surgery All India Institute of Medical Sciences New Delhi, India REFERENCES 1. Still RJ, Hilgenberg AD, Akins CW, et al: Intraoperative aortic dissection. Ann Thorac Surg 53:374-380, 1992 2. Hwang HY, Jeong DS, Kim KH, et al: Iatrogenic type A aortic dissection during cardiac surgery. Interact Cardiovasc Thorac Surg 10:896-899, 2010 3. Williams ML, Sheng S, Gammie JS, et al: Richard E. Clark Award. Aortic dissection as a complication of cardiac surgery: Report from the Society of Thoracic Surgeons database. Ann Thorac Surg 90:1812-1816, 2010 4. Niwa K: Aortic root dilatation in tetralogy of Fallot long-term after repair—Histology of the aorta in tetralogy of Fallot: Evidence of intrinsic aortopathy. Int J Cardiol 103:117-119, 2005 5. Türköz R, Gulcan O, Oguzkurt L, et al: Successful repair of iatrogenic acute aortic dissection with cerebral malperfusion. Ann Thorac Surg 81:345-347, 2006 6. Fleck T, Ehrlich M, Czerny M, et al: Intraoperative iatrogenic type A aortic dissection and perioperative outcome. Interact Cardiovasc Thorac Surg 5:11-14, 2006 7. Varghese D, Riedel BJ, Fletcher SN, et al: Successful repair of intraoperative aortic dissection detected by transesophageal echocardiography. Ann Thorac Surg 73:953-955, 2002 8. Keren A, Kim CB, Hu BS, et al: Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma. J Am Coll Cardiol 28:627-636, 1996 9. Demertzis S, Casso G, Torre T, et al: Direct epiaortic ultrasound scanning for the rapid confirmation of intraoperative aortic dissection. Interact Cardiovasc Thorac Surg 7:725-726, 2008 doi:10.1053/j.jvca.2011.07.032

Sudden Intraoperative Hypertension During Endovascular Abdominal Aortic Repair as a First Sign of Massive Fatal Atheroembolism

tage in early mortality with respect to the open procedure.1 EVAR is offered to patients with limited life expectancy or considered unfit for open repair. However, endovascular aortic procedures are not devoid of complications, with endoleaks being the most frequently observed complication.2 Atheroembolism is another known EVAR complication, but it has been described rarely as an event with fatal consequences.3,4 We report here the case of an 80-year-old man who, while undergoing EVAR, developed unexplained severe hypertension and died of multiple-organ failure on the second postoperative day. The patient was referred to the vascular surgery service because of the incidental finding of a 9-cm abdominal aortic aneurysm. His past medical history included asymptomatic hypertension. Urgent EVAR was scheduled, and general anesthesia with remifentanil and desflurane was chosen because of the high probability of a long and complicated procedure. Guidewire insertion via the femoral artery route was difficult because of a kinked aneurysmal neck, and when the endograft was advanced, sudden hypertension with a preserved heart rate was observed. Blood pressure measured through a right radial artery catheter remained at 220/110 mmHg despite the administration of urapidil, clonidine, labetalol, and elevated desflurane and remifentanil concentrations. After 15 minutes and after repeated intravenous nitroglycerin boluses, the pressure started slowly to decrease, whereas the heart rate rose to 100 beats/min. The patient developed anuria and hyperlactatemia, but was extubated in the operating room at the end of the procedure. Persistent paraplegia was documented in the intensive care unit. On postoperative day 1, he became confused, and overt renal failure and severe metabolic acidosis were present. Livedo reticularis of the lower abdomen, genitalia, and lower limbs became evident, and an abdominal Doppler ultrasound examination documented widespread peripheral arterial occlusion with patent, large arterial vessels. A diagnosis of atheromatous microembolization to all the arterial branches distal to the aneurysmal neck (ie, renal, mesenteric, testicular, external iliac, hypogastric, and probably spinal) was made. Hypotension and hyperkalemia developed, renal replacement therapy was deemed futile, and the patient died on the morning of postoperative day 2. Retrospectively, we attributed the intraoperative hypertension to a sudden increase in systemic vascular resistance because of widespread peripheral arterial occlusion by atheromatous debris. In patients with complex aneurysmal anatomy, atheroembolism should be considered as a potentially fatal complication of EVAR. Unexplained sudden intraoperative hypertension should induce a high degree of suspicion of a catastrophic atheroembolic event. Paolo Grassi, MD Filomena Capone, MD Department of Anesthesia and Intensive Care Ospedale di Cattinara Trieste, Italy REFERENCES

To the Editor: Endovascular aortic repair (EVAR) is considered a relatively safe treatment of abdominal aortic aneurysms, with an advan-

1. United Kingdom EVAR Trial Investigators, Greenhalgh RM, Brown LC, et al: The Unitied Kingdom EVAR Trial Investigators: Endovascular versus open repair of abdominal aortic aneurysm. N Engl J Med 362:1863-1871, 2010