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Peripheral Cardiopulmonary Bypass–Assisted Thymoma Resection
Peripheral Cardiopulmonary Bypass–Assisted Thymoma Resection Jia-Lin Soon, MRCS,* Ruban Poopalalingam, MMed (Anaes),† Chong-Hee Lim, FRCS,* Heng-Nung Koong, FRCS,‡ and Thirugnanam Agasthian, FRCS*
T
HYMOMA IS THE most common tumor of the anterosuperior mediastinum. They vary greatly in size, with most measuring 5 to 10 cm as reported by Lewis et al.1 Smith et al2 reported the largest measuring 34 ⫻ 28 ⫻ 26 cm and weighing 5,700 g. Large thymomas may present with compressive symptoms. A patient with a large thymoma producing severe tracheobronchial compression, superior vena cava (SVC) compression, and pericardial effusion is presented. Her management and the use of peripheral venoarterial bypass under local anesthesia followed by an inhalation anesthetic induction while maintaining spontaneous respiration are described. CASE REPORT
A 52-year-old woman presented with progressive shortness of breath on exertion associated with cough. She had lost 7 to 10 kg over a period of 2 years. Chest radiography revealed a large mediastinal mass (Fig 1). Computed tomography (CT) confirmed tracheal and SVC compression (Fig 2). Two-dimensional echocardiography revealed a large circumferential pericardial effusion with right atrial and ventricular collapse. Open biopsy of the mass under local anesthesia was performed, and percutaneous pericardial drainage yielded 300 mL of serous fluid. Neoadjuvant chemotherapy was completed with partial response for the suspected thymoma. She chose to defer surgery but relapsed 11 months later with the tumor growing from 12.6 ⫻ 9.5 cm to 15.5 ⫻ 9.4 cm (over a 6-month period). The tumor had further compressed the lower trachea and both bronchi, with posterolateral deviation of the trachea and great vessels. The SVC was likewise compressed and displaced to the right. New right-sided pleural nodules were also evident. She had just begun radiotherapy when she decided to risk surgery because she felt more symptomatic with dyspnea on exertion. Clinical signs of a SVC syndrome were absent, and she could lie supine. Palliative resection was performed after venous access was placed in a lower extremity, in view of the SVC compression, and a radial arterial catheter was inserted. Peripheral cardiopulmonary bypass was instituted under local anesthesia with light sedation by using fentanyl and midazolam. Arterial inflow was via the common femoral artery (17F cannula; Medtronic Inc, Anaheim, CA), whereas a 19F (Medtronic Inc) venous cannula was directed up the femoral vein to the right atrium. In brief, the circuit was based on a centrifugal pump, using a membrane oxygenator (Capiox SX18; Terumo Ltd, Tokyo, Japan) with the EBS X-coated circuit (CX ESL002; Terumo Ltd, Tokyo, Japan). The activated coagulation time was maintained at 400 to 600 seconds. Anesthesia was then induced with sevoflurane via spontaneous respiration supported by the PSVPro (Pressure Support with Apnea backup) mode on the ventilator (Datex Ohmeda Aestiva/5; DatexOhmeda Inc, Madison, WI). Pressure support ventilation of 15 cmH2O was delivered to overcome the resistance to breathing and decrease the work of breathing. Endotracheal intubation (regular size 7.5 tube) was then performed without muscle relaxation before sternotomy. On exposure and decompression of the large cystic component of the tumor, muscle relaxant was administered to facilitate surgery and positive pressure ventilation was commenced. The patient was then weaned from CPB once the anesthesiologist was satisfied with the adequacy of mechanical ventilation. Total CPB time was 48 minutes; the heparin was reversed with protamine. The tumor had invaded the pericardium and was encasing both phrenic nerves, the SVC, and the azygos vein. It was compressing the trachea, heart, and main pulmonary artery. Subsequent surgery pro-
ceeded uneventfully with en bloc tumor resection with margins except at both phrenic nerves and the SVC that was marked for subsequent radiotherapy. The oxygen saturation and hemodynamic parameters of the patient were stable throughout surgery. Intraoperatively, 4 units of packed red blood cells, 1 unit of fresh frozen plasma, and 1 unit of platelets were transfused. Parenteral opioids were used for postoperative analgesia. The patient was extubated on the third postoperative day and discharged home on the seventh day with an unremarkable recovery. Histopathology confirmed a World Health Organization type AB/B1 thymoma with changes from neoadjuvant therapy. Focal extracapsular penetration into adjacent fat and resection margin was evident as anticipated. She completed adjuvant radiotherapy with an interval decrease in size of the right pleural nodules on CT scan 4 months later (Fig 3), but these nodules enlarged at 10 months after surgery, although she remained asymptomatic. DISCUSSION
Surgery remains the treatment of choice for thymomas. In the presence of severe central airway compression, anesthetic management can be a challenge. Numerous case reports of life-threatening hypoxia during anesthesia requiring emergent cardiopulmonary support have served as warnings, but the high-risk patient remains loosely defined.3,4 Various techniques have been proposed to deal with distal (eg, tracheobronchial) airway obstruction including spontaneous ventilation; proximal tracheal intubation with distal jet ventilation; rigid bronchoscopy; and prone, semierect, or lateral positioning. However, Narang et al5 emphasized that no ideal technique exists. In a review by Béchard et al,6 anesthetic and postoperative respiratory complications were reported between 7% and 20% and 18%, respectively, in pediatric patients with airway compromise. They reported 0% intraoperative complications (ie, inability to ventilate or peak airway pressure in excess of 40 cmH2O, severe pulmonary shunt, or hemodynamic instability) in their series of 98 adults undergoing 105 anesthetic procedures, having varied their anesthetic techniques in higher-risk patients. They defined the higher-risk patients as those with preoperative cardiorespiratory signs and symptoms (as per Azizkhan et al,7 with orthopnea, stridor, cyanosis, jugular venous distension, or SVC syndrome being severe findings), combined obstructive and restrictive patterns on pulmonary
From the Departments of *Cardiothoracic Surgery and ‡Surgical Oncology, National Heart Center, Singapore; and †Department of Anaesthesia, Singapore General Hospital, Singapore. Address reprint requests to Jia-Lin Soon, MRCS, Department of Cardiothoracic Surgery, National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore, Singapore 168752. E-mail: soon.jia.lin@ singhealth.com.sg © 2007 Elsevier Inc. All rights reserved. 1053-0770/07/2106-0018$32.00/0 doi:10.1053/j.jvca.2006.10.012 Key words: cardiopulmonary bypass, airway obstruction, thoracic surgery
Journal of Cardiothoracic and Vascular Anesthesia, Vol 21, No 6 (December), 2007: pp 867-869
867
868
Fig 1. Chest radiograph showing a large mediastinal tumor with tracheal narrowing and deviation to the left.
spirometry, and CT evidence of tracheal compression ⬎50% or pericardial effusion. Shamberger et al8 suggested that general anesthesia be avoided in children with ⬎50% tracheal area obstruction. Interestingly, 8 adults with tracheal compression ⬎50%, among 97 cases in Béchard’s series, had no intraoperative airway obstruction.6 They postulated that adults may tolerate severe tracheal compression better than children. Nevertheless, they did find a sevenfold increased risk of postoperative respiratory complications in the same cohort. Based on these criteria, the present patient was high risk, with tracheobronchial and SVC compression and pericardial effusion on presentation. Loss of airway control with ventilatory failure often occurs on induction of general anesthesia with muscle paralysis, for the following reasons9: (1) reduction of lung volumes to as little as 500 to 1,500 mL; (2) bronchial smooth muscle relaxation leading to greater airway compression by tumor; and (3) spontaneous diaphragmatic excursions lost, reducing normal transpleural pressure gradient (which keeps the airway open), thereby further aggravating airway compressive effects of the tumor. To preserve a normal transpulmonary pressure and maintain airway tone/patency (especially of the airway distal to the endotracheal tube), the authors chose to maintain spontaneous respiration avoiding muscle paralysis, even after tracheal intubation. This had the further advantage of allowing for assessment of the adequacy of the patient’s ventilation, which gave the confidence to remove CPB-support and reverse anticoagulation before proceeding to complete resection. CPB-assisted resections of advanced thoracic malignancies (especially sarcomas) were limited to case reports until Park et al10 reviewed a series of 10 patients who did not have excessive bleeding. Median packed red blood cell transfusion was 6 units (range, 3-12 units) with 1 re-exploration for postoperative bleeding and coagulopathy. In this selected
SOON ET AL
group of patients, they reported no perioperative mortality and 20% morbidity with significant palliation and some prolonged survivors. Based on this report, the authors have lowered their threshold for instituting CPB since acute airway obstruction puts the patient at unnecessary risk.11-13 Peripheral venoarterial CPB has the benefit of technical simplicity and quick setup.3,4 Insertion by either percutaneous (Seldinger method) or open cannulation can be performed under local anesthesia and can be continued into the postoperative period as extracorporeal membrane oxygenation when necessary until combination chemotherapy and radiotherapy shrinks the tumor.14 In this patient, it was decided to use peripheral CPB for 2 reasons: (1) the imaging evidence of significant major airway obstruction with significant symptoms during her earlier biopsy, and (2) the suspicion of tumor invasion into adjacent great vessels and the heart. Femoral CPB under local anesthesia in a lightly sedated, but spontaneously ventilating patient, gave the added security of ensured oxygenation in the event of failure to ventilate. Induction with the inhalation anesthetic while maintaining spontaneous respiration was achieved by using the PSVPro mode on the Datex Ohmeda ventilator. Once the anesthesiologist was satisfied with the adequacy of mechanical ventilation, muscle paralysis and positive pressure ventila-
Fig 2. CT scan of mediastinal mass with gross tracheal displacement and bronchial narrowing. Aortic arch and arch vessels posteriorly displaced. SVC displaced laterally.
CPB-ASSISTED THYOMA RESECTION
869
Fig 3. Radiograph postresection with corresponding CT images showing widely patent central airway. Postadjuvant radiotherapy changes evident in mediastinum.
tion was commenced with weaning off CPB, protamine reversal, and decannulation. This approach proved to be safe and
effective with close communication between the anesthesiologist and surgeon.
REFERENCES 1. Lewis JE, Wick MR, Scheithaneuer BW, et al: Thymoma: A clinicopathologic review. Cancer 60:2727-2743, 1987 2. Smith WF, DeWall RA, Krumholy RA: Giant thymoma. Chest 58:383-385, 1970 3. Takeda S, Miyoshi S, Omori K, et al: Surgical rescue for lifethreatening hypoxemia caused by mediastinal tumor. Ann Thorac Surg 68:2324-2326, 1999 4. Chao VT, Lim DW, Tao M, et al: Tracheobronchial obstruction as a result of mediastinal mass. Asian Cardiovasc Thorac Ann 14:e17-e18, 2006 5. Narang S, Harte BH, Body SC: Anesthesiol Clin North America 19:559-579, 2001 6. Béchard P, Létourneau L, Lacasse Y, et al: Perioperative cardiorespiratory complications in adults with mediastinal mass. Anesthesiology 100:826-834, 2004 7. Azizkhan RG, Dudgeon DL, Buck JR, et al: Life-threatening airway obstruction as a complication to the management of mediastinal masses in children. J Pediatr Surg 20:816-822, 1985 8. Shamberger RC, Holzman RS, Griscom NT, et al: Prospective evaluation of computed tomography and pulmonary function tests in children with mediastinal masses. Surgery 118:468-471, 1995
9. Neuman GG, Weingarten AE, Abramowitz RM, et al: The anesthetic management of the patient with an anterior mediastinal mass. Anesthesiology 60:144-147, 1984 10. Park BJ, Bacchetta M, Bains MS, et al: Surgical management of thoracic malignancies invading the heart or great vessels. Ann Thorac Surg 78:1024-1030, 2004 11. Goh MH, Liu XY, Goh YS: Anterior mediastinal masses: An anaesthetic challenge. Anaesthesia 54:670-682, 1999 12. Tempe DK, Arya R, Dubey S, et al: Mediastinal mass resection: Femorofemoral cardiopulmonary bypass before induction of anesthesia in the management of airway obstruction. J Cardiothorac Vasc Anesth 15:233-236, 2001 13. Sakuragi T, Rikitake K, Nastuaki M, et al: Complete resection of recurrent thymic carcinoid using cardiopulmonary bypass. Eur J Cardiothorac Surg 21:152-154, 2002 14. Stewart AS, Smythe WR, Aukburg S, et al: Severe acute extrinsic airway compression by mediastinal tumor successfully managed with extracorporeal membrane oxygenation. ASAIO J 44:219-221, 1998
T
HYMOMA IS THE most common tumor of the anterosuperior mediastinum. They vary greatly in size, with most measuring 5 to 10 cm as reported by Lewis et al.1 Smith et al2 reported the largest measuring 34 ⫻ 28 ⫻ 26 cm and weighing 5,700 g. Large thymomas may present with compressive symptoms. A patient with a large thymoma producing severe tracheobronchial compression, superior vena cava (SVC) compression, and pericardial effusion is presented. Her management and the use of peripheral venoarterial bypass under local anesthesia followed by an inhalation anesthetic induction while maintaining spontaneous respiration are described. CASE REPORT
A 52-year-old woman presented with progressive shortness of breath on exertion associated with cough. She had lost 7 to 10 kg over a period of 2 years. Chest radiography revealed a large mediastinal mass (Fig 1). Computed tomography (CT) confirmed tracheal and SVC compression (Fig 2). Two-dimensional echocardiography revealed a large circumferential pericardial effusion with right atrial and ventricular collapse. Open biopsy of the mass under local anesthesia was performed, and percutaneous pericardial drainage yielded 300 mL of serous fluid. Neoadjuvant chemotherapy was completed with partial response for the suspected thymoma. She chose to defer surgery but relapsed 11 months later with the tumor growing from 12.6 ⫻ 9.5 cm to 15.5 ⫻ 9.4 cm (over a 6-month period). The tumor had further compressed the lower trachea and both bronchi, with posterolateral deviation of the trachea and great vessels. The SVC was likewise compressed and displaced to the right. New right-sided pleural nodules were also evident. She had just begun radiotherapy when she decided to risk surgery because she felt more symptomatic with dyspnea on exertion. Clinical signs of a SVC syndrome were absent, and she could lie supine. Palliative resection was performed after venous access was placed in a lower extremity, in view of the SVC compression, and a radial arterial catheter was inserted. Peripheral cardiopulmonary bypass was instituted under local anesthesia with light sedation by using fentanyl and midazolam. Arterial inflow was via the common femoral artery (17F cannula; Medtronic Inc, Anaheim, CA), whereas a 19F (Medtronic Inc) venous cannula was directed up the femoral vein to the right atrium. In brief, the circuit was based on a centrifugal pump, using a membrane oxygenator (Capiox SX18; Terumo Ltd, Tokyo, Japan) with the EBS X-coated circuit (CX ESL002; Terumo Ltd, Tokyo, Japan). The activated coagulation time was maintained at 400 to 600 seconds. Anesthesia was then induced with sevoflurane via spontaneous respiration supported by the PSVPro (Pressure Support with Apnea backup) mode on the ventilator (Datex Ohmeda Aestiva/5; DatexOhmeda Inc, Madison, WI). Pressure support ventilation of 15 cmH2O was delivered to overcome the resistance to breathing and decrease the work of breathing. Endotracheal intubation (regular size 7.5 tube) was then performed without muscle relaxation before sternotomy. On exposure and decompression of the large cystic component of the tumor, muscle relaxant was administered to facilitate surgery and positive pressure ventilation was commenced. The patient was then weaned from CPB once the anesthesiologist was satisfied with the adequacy of mechanical ventilation. Total CPB time was 48 minutes; the heparin was reversed with protamine. The tumor had invaded the pericardium and was encasing both phrenic nerves, the SVC, and the azygos vein. It was compressing the trachea, heart, and main pulmonary artery. Subsequent surgery pro-
ceeded uneventfully with en bloc tumor resection with margins except at both phrenic nerves and the SVC that was marked for subsequent radiotherapy. The oxygen saturation and hemodynamic parameters of the patient were stable throughout surgery. Intraoperatively, 4 units of packed red blood cells, 1 unit of fresh frozen plasma, and 1 unit of platelets were transfused. Parenteral opioids were used for postoperative analgesia. The patient was extubated on the third postoperative day and discharged home on the seventh day with an unremarkable recovery. Histopathology confirmed a World Health Organization type AB/B1 thymoma with changes from neoadjuvant therapy. Focal extracapsular penetration into adjacent fat and resection margin was evident as anticipated. She completed adjuvant radiotherapy with an interval decrease in size of the right pleural nodules on CT scan 4 months later (Fig 3), but these nodules enlarged at 10 months after surgery, although she remained asymptomatic. DISCUSSION
Surgery remains the treatment of choice for thymomas. In the presence of severe central airway compression, anesthetic management can be a challenge. Numerous case reports of life-threatening hypoxia during anesthesia requiring emergent cardiopulmonary support have served as warnings, but the high-risk patient remains loosely defined.3,4 Various techniques have been proposed to deal with distal (eg, tracheobronchial) airway obstruction including spontaneous ventilation; proximal tracheal intubation with distal jet ventilation; rigid bronchoscopy; and prone, semierect, or lateral positioning. However, Narang et al5 emphasized that no ideal technique exists. In a review by Béchard et al,6 anesthetic and postoperative respiratory complications were reported between 7% and 20% and 18%, respectively, in pediatric patients with airway compromise. They reported 0% intraoperative complications (ie, inability to ventilate or peak airway pressure in excess of 40 cmH2O, severe pulmonary shunt, or hemodynamic instability) in their series of 98 adults undergoing 105 anesthetic procedures, having varied their anesthetic techniques in higher-risk patients. They defined the higher-risk patients as those with preoperative cardiorespiratory signs and symptoms (as per Azizkhan et al,7 with orthopnea, stridor, cyanosis, jugular venous distension, or SVC syndrome being severe findings), combined obstructive and restrictive patterns on pulmonary
From the Departments of *Cardiothoracic Surgery and ‡Surgical Oncology, National Heart Center, Singapore; and †Department of Anaesthesia, Singapore General Hospital, Singapore. Address reprint requests to Jia-Lin Soon, MRCS, Department of Cardiothoracic Surgery, National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore, Singapore 168752. E-mail: soon.jia.lin@ singhealth.com.sg © 2007 Elsevier Inc. All rights reserved. 1053-0770/07/2106-0018$32.00/0 doi:10.1053/j.jvca.2006.10.012 Key words: cardiopulmonary bypass, airway obstruction, thoracic surgery
Journal of Cardiothoracic and Vascular Anesthesia, Vol 21, No 6 (December), 2007: pp 867-869
867
868
Fig 1. Chest radiograph showing a large mediastinal tumor with tracheal narrowing and deviation to the left.
spirometry, and CT evidence of tracheal compression ⬎50% or pericardial effusion. Shamberger et al8 suggested that general anesthesia be avoided in children with ⬎50% tracheal area obstruction. Interestingly, 8 adults with tracheal compression ⬎50%, among 97 cases in Béchard’s series, had no intraoperative airway obstruction.6 They postulated that adults may tolerate severe tracheal compression better than children. Nevertheless, they did find a sevenfold increased risk of postoperative respiratory complications in the same cohort. Based on these criteria, the present patient was high risk, with tracheobronchial and SVC compression and pericardial effusion on presentation. Loss of airway control with ventilatory failure often occurs on induction of general anesthesia with muscle paralysis, for the following reasons9: (1) reduction of lung volumes to as little as 500 to 1,500 mL; (2) bronchial smooth muscle relaxation leading to greater airway compression by tumor; and (3) spontaneous diaphragmatic excursions lost, reducing normal transpleural pressure gradient (which keeps the airway open), thereby further aggravating airway compressive effects of the tumor. To preserve a normal transpulmonary pressure and maintain airway tone/patency (especially of the airway distal to the endotracheal tube), the authors chose to maintain spontaneous respiration avoiding muscle paralysis, even after tracheal intubation. This had the further advantage of allowing for assessment of the adequacy of the patient’s ventilation, which gave the confidence to remove CPB-support and reverse anticoagulation before proceeding to complete resection. CPB-assisted resections of advanced thoracic malignancies (especially sarcomas) were limited to case reports until Park et al10 reviewed a series of 10 patients who did not have excessive bleeding. Median packed red blood cell transfusion was 6 units (range, 3-12 units) with 1 re-exploration for postoperative bleeding and coagulopathy. In this selected
SOON ET AL
group of patients, they reported no perioperative mortality and 20% morbidity with significant palliation and some prolonged survivors. Based on this report, the authors have lowered their threshold for instituting CPB since acute airway obstruction puts the patient at unnecessary risk.11-13 Peripheral venoarterial CPB has the benefit of technical simplicity and quick setup.3,4 Insertion by either percutaneous (Seldinger method) or open cannulation can be performed under local anesthesia and can be continued into the postoperative period as extracorporeal membrane oxygenation when necessary until combination chemotherapy and radiotherapy shrinks the tumor.14 In this patient, it was decided to use peripheral CPB for 2 reasons: (1) the imaging evidence of significant major airway obstruction with significant symptoms during her earlier biopsy, and (2) the suspicion of tumor invasion into adjacent great vessels and the heart. Femoral CPB under local anesthesia in a lightly sedated, but spontaneously ventilating patient, gave the added security of ensured oxygenation in the event of failure to ventilate. Induction with the inhalation anesthetic while maintaining spontaneous respiration was achieved by using the PSVPro mode on the Datex Ohmeda ventilator. Once the anesthesiologist was satisfied with the adequacy of mechanical ventilation, muscle paralysis and positive pressure ventila-
Fig 2. CT scan of mediastinal mass with gross tracheal displacement and bronchial narrowing. Aortic arch and arch vessels posteriorly displaced. SVC displaced laterally.
CPB-ASSISTED THYOMA RESECTION
869
Fig 3. Radiograph postresection with corresponding CT images showing widely patent central airway. Postadjuvant radiotherapy changes evident in mediastinum.
tion was commenced with weaning off CPB, protamine reversal, and decannulation. This approach proved to be safe and
effective with close communication between the anesthesiologist and surgeon.
REFERENCES 1. Lewis JE, Wick MR, Scheithaneuer BW, et al: Thymoma: A clinicopathologic review. Cancer 60:2727-2743, 1987 2. Smith WF, DeWall RA, Krumholy RA: Giant thymoma. Chest 58:383-385, 1970 3. Takeda S, Miyoshi S, Omori K, et al: Surgical rescue for lifethreatening hypoxemia caused by mediastinal tumor. Ann Thorac Surg 68:2324-2326, 1999 4. Chao VT, Lim DW, Tao M, et al: Tracheobronchial obstruction as a result of mediastinal mass. Asian Cardiovasc Thorac Ann 14:e17-e18, 2006 5. Narang S, Harte BH, Body SC: Anesthesiol Clin North America 19:559-579, 2001 6. Béchard P, Létourneau L, Lacasse Y, et al: Perioperative cardiorespiratory complications in adults with mediastinal mass. Anesthesiology 100:826-834, 2004 7. Azizkhan RG, Dudgeon DL, Buck JR, et al: Life-threatening airway obstruction as a complication to the management of mediastinal masses in children. J Pediatr Surg 20:816-822, 1985 8. Shamberger RC, Holzman RS, Griscom NT, et al: Prospective evaluation of computed tomography and pulmonary function tests in children with mediastinal masses. Surgery 118:468-471, 1995
9. Neuman GG, Weingarten AE, Abramowitz RM, et al: The anesthetic management of the patient with an anterior mediastinal mass. Anesthesiology 60:144-147, 1984 10. Park BJ, Bacchetta M, Bains MS, et al: Surgical management of thoracic malignancies invading the heart or great vessels. Ann Thorac Surg 78:1024-1030, 2004 11. Goh MH, Liu XY, Goh YS: Anterior mediastinal masses: An anaesthetic challenge. Anaesthesia 54:670-682, 1999 12. Tempe DK, Arya R, Dubey S, et al: Mediastinal mass resection: Femorofemoral cardiopulmonary bypass before induction of anesthesia in the management of airway obstruction. J Cardiothorac Vasc Anesth 15:233-236, 2001 13. Sakuragi T, Rikitake K, Nastuaki M, et al: Complete resection of recurrent thymic carcinoid using cardiopulmonary bypass. Eur J Cardiothorac Surg 21:152-154, 2002 14. Stewart AS, Smythe WR, Aukburg S, et al: Severe acute extrinsic airway compression by mediastinal tumor successfully managed with extracorporeal membrane oxygenation. ASAIO J 44:219-221, 1998