495 Correspondence

performed to detect any fluid in the pericardial sac. If there is a need for repeated pericardiocentesis, tube pericardiostomy should be done. The medium-chain triglyceride diet should be continued for at least four weeks and then changed to a normal, fat-containing diet. Again, the patient should be closely followed to ensure that no accumulation of pericardial fluid oc- curs. We believe that this regimen will be successful in most cases of postoperative chylopericardium. In the rare patient resistant to this form of therapy, one may have to resort to thoracic duct ligation. How- ever, we do not agree with the recommendation of Rose and colleagues [ 11 for partial pericardiectomy with or without ligation of the thoracic duct in all patients. Repeat thoracotomy for this purpose could be avoided by a medium-chain triglyceride diet.

We also take issue with the claim of Rose’s group that their patient is the fifth reported in the literature. In 1976, Delaney and associates [9] reported 2 infants with chylopericardium: 1 following a Glenn operation for tricuspid atresia and the other following repair of interruption of the aortic arch. In 1981, Pollard and colleagues [ 5 ] reported 4 patients with chylopericar- dium following aortocoronary saphenous vein by- pass (1 patient), surgical repair of valvular pulmonic stenosis (1) and isolated ventricular septa1 defect (l), and myotomy and myomectomy for idiopathic hy- pertrophic subaortic stenosis (1). In 1 of these pa- tients cardiac tamponade developed; the remaining 3 patients still had postoperative pericardial tubes in place at the time of development of chylopericar- dium. Three patients were managed successfully by adequate pericardial drainage, or diet, or both treat- ments, while the fourth patient required ligation of the thoracic duct [5]. In all fairness to Rose‘s group, the paper by Pollard and co-workers [5] might have been published around the time Rose and associates [l] submitted their manuscript for publication.

In conclusion, we believe that postoperative chy- lopericardium can be managed with adequate peri- cardial drainage by pericardiocentesis or tube pericar- diostomy or both methods and by a medium-chain triglyceride diet rather than by resorting to partial pericardiectomy with or without thoracic duct liga- tion. Also, there are other reports than those cited by Rose and associates, so their patient is actually not the fifth reported in the literature.

P. Syamasundar Rao, M . D . Consultant Pediatric Cardiologist Department of Pediatrics Hartwell H . Whisennand, M . D . Senior Cardiac Surgeon

Baylor Heart Team King Fuisal Specialist Hospital and

Research Centre PO Box 3354 Riyadh, Saudi Arabia 11212

References 1. Rose DM, Colvin SB, Danilowicz D, Isom OW:

Cardiac tamponade secondary to chylopericar- dium following cardiac surgery: case report and review of the literature. Ann Thorac Surg 34:333, 1982

2. Feteih W, Rao PS, Whisennand HH, et al: Chy- lopericardium: a new complication of Blalock- Taussig anastomosis. J Thorac Cardiovasc Surg (in press, 1983)

3. Thomas CS Jr, McGoon DC: Isolated massive chy- lopericardium following cardiopulmonary bypass. J Thorac Cardiovasc Surg 61:945, 1971

4. Jacob T, de Leva1 M, Stark J, Waterston DJ: Chy- lopericardium as a complication of aortopulmo- nary shunt. Arch Surg 108:870, 1971

5. Pollard WM, Schuchmann GF, Bowen TE: Isolated chylopericardium after cardiac operations. J Thorac Cardiovasc Surg 81:943, 1981

6. Hashim SA, Roholt HB, Babayan VK, Van Itallie TB: Treatment of chyloria and chylothorax with medium-chain triglycerides. New Engl J Med 270:756, 1964

7. Kosloske AM, Martin LW, Schubert WK: Manage- ment of chylothorax in children by thoracentesis and medium-chain triglyceride feedings. J Pediatr Surg 9:365, 1974

8. Hawker RE, Cartmill TB, Celermajer JM, Bowdler JD: Chylous pericardial effusion complicating aorta-right pulmonary artery anastomosis. J Thorac Cardiovasc Surg 63:491, 1972

9. Delaney A, Diacoff GR, Hess PJ, Victoria B: Chy- lopericardium with cardiac tamponade after car- diovascular surgery in two patients. Chest 69:381, 1976

Reply To the Editor:

We appreciate the remarks by Drs. Rao and Whisen- nand with regard to our article concerning chy- lopericardium [l]. We will respond to their criticisms in somewhat reverse fashion.

First, the report of Pollard and colleagues [2] was published after our manuscript had been submitted to The Annals of Thoracic Surgery. Second, we apol- ogize to the editors of The Annals of Thoracic Surgery and to Delaney and associates for the omission of their article [3]. This was a result of a computer quirk. When we commenced our Medline computer-based literature search for articles on chylopericardium the reference words entered into the computer were ”pericardial effusion,” ”pleural effusion,” “chylus,” “chyle,” and “chylous.“ “Chylopericardium” is not separately referenced in the Index Medicus. With these words referenced, the computer-based litera- ture search obtained all previously published articles

496 The Annals of Thoracic Surgery Vol 36 No 4 October 1983

concerning chylopericardium except for the article by Delaney and associates. On computer cross-check, it was found that this article is referenced under “car- diac tamponade,” ”chyle,” ”heart surgery,” and ”pericardium.” Since two of the reference words are necessary for the article to be listed in the Medline report, the article by Delaney and colleagues was in- advertently omitted from our own search.

Drs. Rao and Whisennand suggest that the primary treatment for chylopericardium should be pericar- diocentesis followed by a medium-chain triglyceride diet. We believe that for pericardial effusions without cardiac tamponade, this may be an accepted method of treatment. However, with life-threatening cardiac tamponade, it may be less than satisfactory.

Although pericardiocentesis has been recom- mended by some for treatment of cardiac tamponade [4], this technique may provide unsatisfactory relief of tamponade, particularly in the postoperative pa- tient. In addition, pericardiocentesis has a complica- tion rate of 5 to 35% and an associated mortality rate of up to 5% in some published series [5]. We [6] and others [7] think that a subxiphoid approach or an an- terior thoracotomy is preferable for relief of life- threatening cardiac tamponade following cardiac pro- cedures.

Also, it is not uncommon for pericardial or cardiac lymphatics to be injured during the course of a car- diac operation. We suggest that a distinction be made between persistent low-grade effusion resulting from an injured cardiac lymphatic and life-threatening car- diac tamponade occurring as a result of obstruction to normal lymphatic flow in addition to a lymphatic injury. This pattern of events was suggested by Thomas and McGoon [8] in 1971. As Rao and Whisennand point out, the use of a medium-chain triglyceride diet can decrease the amount of thoracic duct lymph flow. However, the total flow in the tho- racic duct can range from 14 to 110 ml per hour [9], with an average flow of 1.3 ml/kg/hr [lo]. Thus, de- spite the use of a medium-chain triglyceride diet or even of intravenous hyperalimentation as has been recommended by some authors [ll], patients who have obstruction of lymphatic drainage in addition to lymphatic injury most likely will have recurrent pericardial effusion and tamponade. This is well demonstrated in Case 4 of Pollard and associates [2].

We maintain that with life-threatening cardiac tam- ponade secondary to chylopericardium, a safer treat- ment is partial pericardiectomy with suture ligation of any visible injured lymphatics. We also maintain that in this group of patients, there is a strong likelihood that the effusion will recur; to avoid sudden death secondary to tamponade, a partial pericardiectomy should be performed. If there is still recurrent drain- age despite the use of a medium-chain triglyceride diet or intravenous hyperalimentation, then thoracic duct ligation can be performed.

In conclusion, as Drs. Rao and Whisennand sug- gest, pericardial effusion secondary to chylopericar- dium without lymphatic obstruction can be treated with pericardial drainage and a medium-chain tri- glyceride diet. We prefer a subxiphoid approach rather than pericardiocentesis in a postoperative pa- tient. However, in patients with recurrent pericardial effusion or life-threatening cardiac tamponade sec- ondary to chylopericardium, most likely there is ob- struction to lymphatic flow in addition to lymphatic injury, and in this setting partial pericardiectomy with suture ligation of the injured lymphatic is our recommended treatment. Additionally, thoracic duct ligation may be necessary if there is persistent drainage.

Daniel M . Rose, M . D Department of Thoracic and

Cardiovascular Surgery Maimonides Medical Center 4802 Tenth Ave Brooklyn, NY 11 21 9

Steven B. Colvin, M . D . Director, Department of Thoracic

and Cardiovascular Surgery Bellevue Medical Center First Ave and 27th St New York, NY 10016

0. W. Isom, M.D. Director, Department of Thoracic

and Cardiovascular Surgery New York University Hospital and

Medical Center 550 First Ave New York, NY 10016

References 1. Rose DM, Colvin SB, Danilowicz D, Isom OW:

Cardiac tamponade secondary to chylopericar- dium following cardiac surgery: case report and review of the literature. Ann Thorac Surg 34:333, 1982

2. Pollard WM, Schuchmann GF, Bowen TE: Isolated chylopericardium after cardiac opera- tions. J Thorac Cardiovasc Surg 61:943, 1981

3. Delaney A, Diacoff GR, Hess PJ, Victoria B: Chy- lopericardium with cardiac tamponade after car- diovascular surgery in two patients. Chest 69:381, 1976

4. Darsee JR, Braunwald E: Diseases of the pericar- dium. In Braunwald E (ed): Heart Disease: A Textbook of Cardiovascular Medicine. Philadel- phia, Saunders, 1980, chap 41

5. Wong B, Murphy J, Chang CJ, et al: The risk of cardiocentesis. Am J Cardiol 44:1110, 1979

497 Correspondence

6. Engelman RM, Spencer FC, Reed GE, Tice BA: Cardiac tamponade following open-heart sur- gery. Circulation 41:Suppl 2165, 1970

7. Santos GH, Frater RWM: The subxiphoid ap- proach in the treatment of pericardial effusion. Ann Thorac Surg 23:467, 1977

8. Thomas CS Jr, McGoon DC: Isolated massive chylopericardium following cardiopulmonary by- pass. J Thorac Cardiovasc Surg 61:945, 1971

9. Ross JK: A review of the surgery of the thoracic duct. Thorax 16:12, 1961

10. Bessone LN, Ferguson TB, Burford TH: Chy- lothorax (collective review). Ann Thorac Surg 12527, 1971

11. Wiener S, Owens L, Salzberg AM: Chylothorax after Bochdalek herniorrhaphy in a neonate: treatment with intravenous hyperalimentation. J Thorac Cardiovasc Surg 65:200, 1973