- Email: [email protected]
Bilateral Chylothorax Following Thoracic Duct Ligation: Case Report and Review of the Literature
Case Reports
Bilateral Chylothorax Following Thoracic Duct Ligation: Case Report and Review of the Literature Kevin Robinson, MD, Eric S. Weinstein, MD, and Mark Langsfeld, MD, Albuquerque, New Mexico
Bilateral chylothorax following thoracic duct injury is a rare occurrence. Since 1907 there have been only six reports in the literature of this potentially serious complication. We report a case of bilateral chytothorax following ligation of the cervical thoracic duct during a left subclavian to carotid artery transposition. (Ann Vasc Surg 1996;10:390-395.)
Bilateral c h y l o t h o r a x following injury to or ligation of the cervical p o r t i o n of the thoracic duct is a rare b u t p o t e n t i a l l y serious c o m p l i c a t i o n . Stuart ~ in 1907 r e v i e w e d 42 cases of operative injury to the thoracic d u c t in the n e c k a n d f o u n d t h r e e patients, all of w h o m died, w i t h c h y l o t h o r a x . Since 1907 t h e r e h a v e b e e n only six single case reports of bilateral c h y l o t h o r a x following surgical injury to or ligation of t h e cervical thoracic duct. 2-7 I n c o n t r a s t to the first three p a t i e n t s described, all r e p o r t e d since t h a t t i m e h a v e m a d e full recoveries. W e describe a case of bilateral c h y l o t h o r a x following ligation of the cervical thoracic d u c t d u r i n g a left s u b c l a v i a n to carotid artery t r a n s p o s i t i o n . The literature is r e v i e w e d a n d the a n a t o m y , diagnosis, a n d m a n a g e m e n t of c h y l o t h o r a x are discussed.
CASE REPORT A 68-year-old female smoker with a history of steroiddependent rheumatoid arthritis presented to the general medicine clinic 3 days prior to admission with cyanotic, painful, and cool second through fifth fingers From the Division of Vascular Surgery, University of New Mexico School of Medicine, Albuquerque, N.M. Reprint requests: Eric S. Weinstein, MD, Chief, Division of Vascular Surgery, University of New Mexico Hospital, 2-ACC, 2211 Lomas Blvd. N.E., Albuquerque, NM 87131-5341. 390
of her left hand. Procardia was prescribed for a presumptive diagnosis of Raynaud's syndrome, but her symptoms were not relieved. The patient denied any history of blanching, erythema, or cold intolerance. There was no history of cardiac dysrhythmia, coronary artery disease, or congestive heart failure. On examination she had a cool left hand with pallor and tissue necrosis of the distal third fingertip. Brachial artery pressures were equal bilaterally, and palpable radial and ulnar pulses were noted in the affected extremity. A bruit was auscultated over the left clavicle. An arteriogram of the aortic arch and upper extremity demonstrated an atherosclerotic, ulcerated plaque just distal to the origin of the left subclavian artery with distal occlusions of several digital arteries (Fig. 1 ). The patient was treated with anticoagulants and underwent a left subclavian to common carotid artery transposition. The thoracic duct was identified during the dissection, ligated, and then divided to facilitate exposure. Postoperatively the patient had mild abdominal distention, nausea, and mild tachypnea. These symptoms resolved with an enema. A postoperative chest x-ray film demonstrated blunting of the costophrenic angles bilaterally, although her lung fields remained clear and oxygen saturation was 95% on room air (Fig. 2, A). The patient was discharged on postoperative day 2 but returned the following morning with complaints of nausea, vomiting, and shortness of breath. Physical examination revealed decreased breath sounds bilaterally. She was afebrile with normal vital signs except for mild tachypnea. The operative site was without induration, erythema, or drainage. The patient was placed
VoL 10, No. 4 1996
Case reports
A
B
Fig. 1. A, Digital subtraction arch aortogram. Ulcerated atherosclerotic plaque in the proximal subclavian artery (black arrowhead). 13, Digital subtraction arteriogram of the left hand showing multiple digital artery occlusions (black arrows).
391
392
Annals of Vascular Surgery
Casereports
A
B
C
Fig. 2, A, Immediate postoperative chest x-ray film. Large hemoctip marks ligated subclavian artery (white arrow). Minimal blunting of the bilateral costophrenic angles is noted. Readmission posteroanterior (B) and lateral (C) chest x-ray films demonstrate bilateral pleural effusions.
Vol. lO, No, 4
1996
Case reports
393
Fig. 3. Posteroanterior chest x-ray film 4 weeks postoperatively demonstrating resolution of bilateral pleural effusions.
on oxygen via nasal cannula and readmitted. A chest x-ray film was remarkable for bilateral pteural effusions (Fig. 2, B and C). Consultation wSth a cardiologist confirmed the absence of congestive heart failure. Diagnostic and therapeutic right-sided pleuracentesis was performed with aspiration of 300 ml of milky fluid. Laboratory evaluation of the fluid demonstrated a triglyceride level of 441 mg/dl (serum triglycerides 171 mg/dl), amylase 40 U/L, lactate dehydrogenase 489 U/L, glucose 108 mg/dl, red blood count < 10,000/ram 3, and white blood count 200 mm 3 (25% neutrophils, 60% lymphocytes). A diagnosis of bilateral chylothorax was made. The patient's respiratory symptoms improved following pleuracentesis. She was placed on a fat-free enteral diet and followed for several days with serial chest x-ray films. When it became clear that the effusions were stable, the patient was discharged and followed closely until resolution of the pleural effusions over the next several weeks (Fig. 3). The patient lost the distal phalynx of her left third finger as a result of necrosis and autoamputation but has otherwise made a full recovery.
DISCUSSION Chylothoraces have been described following almost every k n o w n thoracic surgical p r o c e d u r e and complicate b o t h p e n e t r a t i n g a n d blunt tho-
racic t r a u m a , s-H Chylous fistulas after radical neck dissections occur in 1.1% to 4% of cases6"12; however, bilateral c h y l o t h o r a x following ligation or injury of the cervical p o r t i o n of the thoracic duct occurs rarely, w i t h only n i n e cases previously reported a n d o n l y one of these was w i t h o u t a c o n c o m i t a n t chylous fistula. The first a t t e m p t at ligation of the thoracic duct was probably p e r f o r m e d in 1675, 48 years after the discovery of the l y m p h a t i c system. 13 Animal studies over the n e x t 300 years d e m o n strated a wide intraspecies variation w i t h regard to the effects of thoracic duct ligation that appears to be related to the d e v e l o p m e n t a n d ade q u a c y of collateral drainage in individual animals. ~3-15L y m p h pressures in excess of 60 c m H20 have b e e n d o c u m e n t e d in cats following ligation of the thoracic duct in the chest. ~ The thoracic duct originates f r o m the cisterna chyle in the midline at the level of the second l u m b a r vertebra a n d enters the t h o r a x t h r o u g h the aortic hiatus to the right of the midline. It t h e n ascends extrapleurally b e t w e e n the aorta and the azygous vein. ~6 The duct is almost always a single structure at the T8-12 level. ~7 It crosses the m e d i a s t i n u m at the T4-6 level a n d ascends extrapleurally to the left of the esophagus cross-
394
Annals of Vascular Surgery
Casereports
Scolenus anticus m.
Cava
lie
Fig. 4. Anatomy of the thoracic duct.
ing behind the aortic arch and left subclavian artery. The duct then curves anteriorly across the medial edge of the scalenus anticus muscle insertion and empties into the venous circulation in one or more branches near the c o n f u e n c e of the left subclavian and internal jugular veins 1°'~6'~ (Fig. 4). The duct has a muscular wall controlled by the autonomic nervous system and contains valves that prevent backflow. ~° Its route is variable in 40% to 60% of cases, with m a n y collateral vessels communicating with the azygous and intercostal veins) 7'~s Chyle is an opalescent fluid with a characteristic composition) °'~8 Nevertheless, the gross appearance of a pleural effusion is a poor indicator of its composition in cases of possible chylothorax. ~9 In one series less than half of chylous effusions were described as "chylous. ''2° Fat globules, considered diagnostic of chylous effusions, have been identified using Sudan III stains of pleural fluid. However, their absence does not rule out chylothorax and analysis of pleural fluid fat content m a y be misleading. 2°'2' The technique of quantitative analysis of pleural fluid for triglycerides and cholesterol followed by electrophoresis to determine lipoprotein profiles has been used in the examination of
pleural effusions. 2°'22 In a series of 141 patients Staats et al. 2° found that chylous effusions generally had a cholesterol/triglyceride ratio of less than one, whereas nonchylous effusions tended to have ratios greater than one. There was, however, a significant overlap between the two groups. Examination of cholesterol levels alone demonstrated no significant difference between chylous and nonchylous effusions. However, differences in triglyceride concentrations between the two groups were significant (chylous median 249 rag/d1, range 49 to 2270 mg/dl; nonchylous median 33 rag/d1, range 13 to 107 mg/dl). Using gaussian distribution techniques it was estimated that pleural fluid with a triglyceride level > 110 mg/dl has less than a 1% chance of not being chylous, whereas fluid with triglyceride levels < 50 rag/d1 had no more than a 5% chance of being chylous. For intermediate levels of triglycerides the authors recommended the more complex and expensive lipoprotein analysis, which more reliably excludes the presence of chylomicrons.20 Nutritional support is essential in the successful management of chylothorax, especially when there is an associated chylous fistula. Patients may lose in excess of 2000 ml of chyle per day containing 1 to 6 gm/dl of protein, 20% to 30% of their circulating fat, fat-soluble vitamins, important enzymes, clotting factors, and electrolytes. 23~6 In addition, patients may suffer from embarassment of cell-mediated immunity secondary to a loss of T cells. 2729 Ingested fats greatly increase the flow of chyle, although enteral fatfree diets and even water taken by m o u t h may significantly increase thoracic duct flow. 1°'23 The first breakthrough in the nutritional support of patients with chylothorax involved the use of medium-chain triglycerides, which are preferentially absorbed through the portal venous system. 26 Total parenteral nutrition and bowel rest can further minimize chylous output w h e n compared to fat-flee enteral feedings. 23"25 A pathophysiologic basis for chylothorax in cases associated with neck dissection has been postulated. Immediately after ligation of the thoracic duct, there is an increase in the thoracic duct hydrostatic pressure as the chyle volume exceeds the "receiving capacity" of the collateral network. As the pressure increases, nontraumatic extravasation of chyle occurs. The negative inspiratory pressure in the chest leads to extravasation of chyle into the mediastinum and eventually, through the macerated pleura, produces bilateral chylothoraces.3'5'3° This hypothesis is consistent with findings in animal studies ~3'~4and with reports of bilateral
Vol. 10, No. 4 1996
chylothoraces occurring in humans w h o have thrombosis of the bilateral jugulosubclavian confluences and the superior vena cava. 3~'3z All surviving patients reported in the literature, including our own, had spontaneous resolution of chylothoraces with conservative treatment. Thoracentesis and closed thoracostomy tube drainage may be used both to establish the diagnosis and treat the symptoms. Resolution presumably occurs after adequate enlargement of collateral vessels, reduction of lymph pressure, and reabsorbtion of extravasated chyle. REFERENCES 1. Stuart WJ. Operative injury of the thoracic duct in the neck. Edinburgh Med J 1907;22:301-317. 2. Frazell EL, Harrold CC, Rasmussen L. Bilateral chylothorax. Ann Surg 1951;134:135-137. 3. Coates JL, Desanto LW. Bilateral chylothorax as a complication of radical neck dissection, d Laryngol Otolaryngol 1976; 90:967-970. 4. Saraaceno CA, Farrior RT. Bilateral chylothorax, a rare complication of neck dissection. Arch Otolaryngol 1981;107:497499. 5. Har-E1 G, Segal K, Sidi J. Bilateral chylothorax complicating radical neck dissection: Report of a case with no concurrent external chylous leakage. Head Neck Surg 1985;7:225-230. 6. Ng RS, Kerbavaz ILl, Hilsinger RL. Bilateral chylothorax from radical neck dissection. Otolaryngol Head Neck Surg 1985; 93:814-817. 7. Pace-Balzan A, Moriarty B. Bilateral chylothorax following left radical neck dissection. J Laryngol Otolaryngol 1988;102: 288-290. 8. Laaveg SJ, Spraque BL Traumatic chylothorax, a complication of fracture dislocation of the spine. J Bone Joint Surg 1978;60A:708-709. 9. Dulchavsky SA, Ledgerwood AM, Lucas CE. Management of chylothorax after blunt chest trauma. J Trauma 1988;28: 1400-1401. 10. Robinson CLN. The management of chylothorax. Ann Thorac Surg 1985;39:90-95. 11. Birt AB, Connolly NK. Traumatic chylothorax: A report of a case and a survey of the literature. Br J Surg 1951;39:564568. 12. Fitz-Hugh SG, Cowgill R. Chylous fistula: Complication of neck dissection. Arch Otolaryngol 1970;91:543-547. 13. Lee FC. The establishment of collateral circulation following ligation of the thoracic duct. Bull Johns Hopkins Hosp 1922;33:21-31.
Case reports
395
14. Blalock A, Robinson CS, Cunningham RS, et al. Experimental studies on lymphatic blockage. Arch Surg 1937;34:10491071. 15. Lee FC. Permeability of lymph vessels and lymph pressure. Arch Surg 1944;48:35%365. 16. Schuknan A, Fataar MB, Dalrymple R, et al. The lymphographic anatomy of chylothorax. Br J Radiol 1978;5t:420427. 17. Selle JG, Snyder WH, Schreiber JT. Chylothorax: Indications for surgery. Ann Surg 1973;177:245-249. 18, Teba L, Dedhia HV, Bowen R, et al. Chylothorax review. Crit Care Med 1985;13:49-52. 19. Klepser RG, Berry JE. The diagnosis and surgical management of chylothorax with aid of lipophilic dyes. Dis Chest 1954;25:409-426. 20. Staats BA, Ellefson RD, Budahon LL, et al. The lipoprotein profile of chylous and nonchylous pleural effusions. Mayo Clin Proc 1980;55:700-704. 21. Denborough MA, Nestel PJ. Milky effusions. Med J Aust 1964;2:874-876. 22. Seriff NS, Cohen PS, Samuel P, et al. Chylothorax: Diagnosis by llpoprotein electrophoresis of serum and pleural fluid. Thorax 1977;32:98-100. 23. Bozzetti F, Arullani A, Baticci F, et al. Management of lymphatic fistulas by total parenteral nutrition. J Parenteral Nutr 1982;6:526-527. 24. Engevik L. Traumatic chylothorax. Scand J Thorac Cardiovasc Surg 1976;10:77-78. 25. Ramos W, Faintuch J. Nutritional management of thoracic duct fistulas. A comparative study of parenteral versus enteral nutrition. J Parenteral Nutr 1986;10:519-521. 26. Hashim SA, Roholt HD, Babayan VK, et al. Treatment of chyluria and chylothorax with medium-chain triglyceride. N Engl J Med 1964;270:756-761. 27. Breaux J, Marks C. Chylothorax causing reversible T-cell depletion. J Trauma 1988;28:705-707. 28. Milsom JW, Kron IL, Rheuban KS, et al. Chylothorax: An assessment of current surgical management. J Thorac Cardiovasc Surg 1985;89:221-227. 29. Ferguson MK, Little AG, Skinner DB. Current concepts in the management of postoperative chylothorax. Ann Thorac Surg 1985;40:542-545. 30. Cavallo CA, Hirata RM, Jaques DA. Chylothorax complicating radical neck dissection. Ann Surg 1975;41:266-268. 31. Thurer RJ. A complication of subclavian vein catheterization and parenteral hyperalimentation. J Thorac Cardiovasc Surg 1976;71:465-468. 32. Dhande V, Kattwinkel J, Slford B. Recurrent bilateral pleural effusions secondary to superior vena cava obstruction as a complication of central venous catheterization. Pediatrics 1983;72:109-113.
Bilateral Chylothorax Following Thoracic Duct Ligation: Case Report and Review of the Literature Kevin Robinson, MD, Eric S. Weinstein, MD, and Mark Langsfeld, MD, Albuquerque, New Mexico
Bilateral chylothorax following thoracic duct injury is a rare occurrence. Since 1907 there have been only six reports in the literature of this potentially serious complication. We report a case of bilateral chytothorax following ligation of the cervical thoracic duct during a left subclavian to carotid artery transposition. (Ann Vasc Surg 1996;10:390-395.)
Bilateral c h y l o t h o r a x following injury to or ligation of the cervical p o r t i o n of the thoracic duct is a rare b u t p o t e n t i a l l y serious c o m p l i c a t i o n . Stuart ~ in 1907 r e v i e w e d 42 cases of operative injury to the thoracic d u c t in the n e c k a n d f o u n d t h r e e patients, all of w h o m died, w i t h c h y l o t h o r a x . Since 1907 t h e r e h a v e b e e n only six single case reports of bilateral c h y l o t h o r a x following surgical injury to or ligation of t h e cervical thoracic duct. 2-7 I n c o n t r a s t to the first three p a t i e n t s described, all r e p o r t e d since t h a t t i m e h a v e m a d e full recoveries. W e describe a case of bilateral c h y l o t h o r a x following ligation of the cervical thoracic d u c t d u r i n g a left s u b c l a v i a n to carotid artery t r a n s p o s i t i o n . The literature is r e v i e w e d a n d the a n a t o m y , diagnosis, a n d m a n a g e m e n t of c h y l o t h o r a x are discussed.
CASE REPORT A 68-year-old female smoker with a history of steroiddependent rheumatoid arthritis presented to the general medicine clinic 3 days prior to admission with cyanotic, painful, and cool second through fifth fingers From the Division of Vascular Surgery, University of New Mexico School of Medicine, Albuquerque, N.M. Reprint requests: Eric S. Weinstein, MD, Chief, Division of Vascular Surgery, University of New Mexico Hospital, 2-ACC, 2211 Lomas Blvd. N.E., Albuquerque, NM 87131-5341. 390
of her left hand. Procardia was prescribed for a presumptive diagnosis of Raynaud's syndrome, but her symptoms were not relieved. The patient denied any history of blanching, erythema, or cold intolerance. There was no history of cardiac dysrhythmia, coronary artery disease, or congestive heart failure. On examination she had a cool left hand with pallor and tissue necrosis of the distal third fingertip. Brachial artery pressures were equal bilaterally, and palpable radial and ulnar pulses were noted in the affected extremity. A bruit was auscultated over the left clavicle. An arteriogram of the aortic arch and upper extremity demonstrated an atherosclerotic, ulcerated plaque just distal to the origin of the left subclavian artery with distal occlusions of several digital arteries (Fig. 1 ). The patient was treated with anticoagulants and underwent a left subclavian to common carotid artery transposition. The thoracic duct was identified during the dissection, ligated, and then divided to facilitate exposure. Postoperatively the patient had mild abdominal distention, nausea, and mild tachypnea. These symptoms resolved with an enema. A postoperative chest x-ray film demonstrated blunting of the costophrenic angles bilaterally, although her lung fields remained clear and oxygen saturation was 95% on room air (Fig. 2, A). The patient was discharged on postoperative day 2 but returned the following morning with complaints of nausea, vomiting, and shortness of breath. Physical examination revealed decreased breath sounds bilaterally. She was afebrile with normal vital signs except for mild tachypnea. The operative site was without induration, erythema, or drainage. The patient was placed
VoL 10, No. 4 1996
Case reports
A
B
Fig. 1. A, Digital subtraction arch aortogram. Ulcerated atherosclerotic plaque in the proximal subclavian artery (black arrowhead). 13, Digital subtraction arteriogram of the left hand showing multiple digital artery occlusions (black arrows).
391
392
Annals of Vascular Surgery
Casereports
A
B
C
Fig. 2, A, Immediate postoperative chest x-ray film. Large hemoctip marks ligated subclavian artery (white arrow). Minimal blunting of the bilateral costophrenic angles is noted. Readmission posteroanterior (B) and lateral (C) chest x-ray films demonstrate bilateral pleural effusions.
Vol. lO, No, 4
1996
Case reports
393
Fig. 3. Posteroanterior chest x-ray film 4 weeks postoperatively demonstrating resolution of bilateral pleural effusions.
on oxygen via nasal cannula and readmitted. A chest x-ray film was remarkable for bilateral pteural effusions (Fig. 2, B and C). Consultation wSth a cardiologist confirmed the absence of congestive heart failure. Diagnostic and therapeutic right-sided pleuracentesis was performed with aspiration of 300 ml of milky fluid. Laboratory evaluation of the fluid demonstrated a triglyceride level of 441 mg/dl (serum triglycerides 171 mg/dl), amylase 40 U/L, lactate dehydrogenase 489 U/L, glucose 108 mg/dl, red blood count < 10,000/ram 3, and white blood count 200 mm 3 (25% neutrophils, 60% lymphocytes). A diagnosis of bilateral chylothorax was made. The patient's respiratory symptoms improved following pleuracentesis. She was placed on a fat-free enteral diet and followed for several days with serial chest x-ray films. When it became clear that the effusions were stable, the patient was discharged and followed closely until resolution of the pleural effusions over the next several weeks (Fig. 3). The patient lost the distal phalynx of her left third finger as a result of necrosis and autoamputation but has otherwise made a full recovery.
DISCUSSION Chylothoraces have been described following almost every k n o w n thoracic surgical p r o c e d u r e and complicate b o t h p e n e t r a t i n g a n d blunt tho-
racic t r a u m a , s-H Chylous fistulas after radical neck dissections occur in 1.1% to 4% of cases6"12; however, bilateral c h y l o t h o r a x following ligation or injury of the cervical p o r t i o n of the thoracic duct occurs rarely, w i t h only n i n e cases previously reported a n d o n l y one of these was w i t h o u t a c o n c o m i t a n t chylous fistula. The first a t t e m p t at ligation of the thoracic duct was probably p e r f o r m e d in 1675, 48 years after the discovery of the l y m p h a t i c system. 13 Animal studies over the n e x t 300 years d e m o n strated a wide intraspecies variation w i t h regard to the effects of thoracic duct ligation that appears to be related to the d e v e l o p m e n t a n d ade q u a c y of collateral drainage in individual animals. ~3-15L y m p h pressures in excess of 60 c m H20 have b e e n d o c u m e n t e d in cats following ligation of the thoracic duct in the chest. ~ The thoracic duct originates f r o m the cisterna chyle in the midline at the level of the second l u m b a r vertebra a n d enters the t h o r a x t h r o u g h the aortic hiatus to the right of the midline. It t h e n ascends extrapleurally b e t w e e n the aorta and the azygous vein. ~6 The duct is almost always a single structure at the T8-12 level. ~7 It crosses the m e d i a s t i n u m at the T4-6 level a n d ascends extrapleurally to the left of the esophagus cross-
394
Annals of Vascular Surgery
Casereports
Scolenus anticus m.
Cava
lie
Fig. 4. Anatomy of the thoracic duct.
ing behind the aortic arch and left subclavian artery. The duct then curves anteriorly across the medial edge of the scalenus anticus muscle insertion and empties into the venous circulation in one or more branches near the c o n f u e n c e of the left subclavian and internal jugular veins 1°'~6'~ (Fig. 4). The duct has a muscular wall controlled by the autonomic nervous system and contains valves that prevent backflow. ~° Its route is variable in 40% to 60% of cases, with m a n y collateral vessels communicating with the azygous and intercostal veins) 7'~s Chyle is an opalescent fluid with a characteristic composition) °'~8 Nevertheless, the gross appearance of a pleural effusion is a poor indicator of its composition in cases of possible chylothorax. ~9 In one series less than half of chylous effusions were described as "chylous. ''2° Fat globules, considered diagnostic of chylous effusions, have been identified using Sudan III stains of pleural fluid. However, their absence does not rule out chylothorax and analysis of pleural fluid fat content m a y be misleading. 2°'2' The technique of quantitative analysis of pleural fluid for triglycerides and cholesterol followed by electrophoresis to determine lipoprotein profiles has been used in the examination of
pleural effusions. 2°'22 In a series of 141 patients Staats et al. 2° found that chylous effusions generally had a cholesterol/triglyceride ratio of less than one, whereas nonchylous effusions tended to have ratios greater than one. There was, however, a significant overlap between the two groups. Examination of cholesterol levels alone demonstrated no significant difference between chylous and nonchylous effusions. However, differences in triglyceride concentrations between the two groups were significant (chylous median 249 rag/d1, range 49 to 2270 mg/dl; nonchylous median 33 rag/d1, range 13 to 107 mg/dl). Using gaussian distribution techniques it was estimated that pleural fluid with a triglyceride level > 110 mg/dl has less than a 1% chance of not being chylous, whereas fluid with triglyceride levels < 50 rag/d1 had no more than a 5% chance of being chylous. For intermediate levels of triglycerides the authors recommended the more complex and expensive lipoprotein analysis, which more reliably excludes the presence of chylomicrons.20 Nutritional support is essential in the successful management of chylothorax, especially when there is an associated chylous fistula. Patients may lose in excess of 2000 ml of chyle per day containing 1 to 6 gm/dl of protein, 20% to 30% of their circulating fat, fat-soluble vitamins, important enzymes, clotting factors, and electrolytes. 23~6 In addition, patients may suffer from embarassment of cell-mediated immunity secondary to a loss of T cells. 2729 Ingested fats greatly increase the flow of chyle, although enteral fatfree diets and even water taken by m o u t h may significantly increase thoracic duct flow. 1°'23 The first breakthrough in the nutritional support of patients with chylothorax involved the use of medium-chain triglycerides, which are preferentially absorbed through the portal venous system. 26 Total parenteral nutrition and bowel rest can further minimize chylous output w h e n compared to fat-flee enteral feedings. 23"25 A pathophysiologic basis for chylothorax in cases associated with neck dissection has been postulated. Immediately after ligation of the thoracic duct, there is an increase in the thoracic duct hydrostatic pressure as the chyle volume exceeds the "receiving capacity" of the collateral network. As the pressure increases, nontraumatic extravasation of chyle occurs. The negative inspiratory pressure in the chest leads to extravasation of chyle into the mediastinum and eventually, through the macerated pleura, produces bilateral chylothoraces.3'5'3° This hypothesis is consistent with findings in animal studies ~3'~4and with reports of bilateral
Vol. 10, No. 4 1996
chylothoraces occurring in humans w h o have thrombosis of the bilateral jugulosubclavian confluences and the superior vena cava. 3~'3z All surviving patients reported in the literature, including our own, had spontaneous resolution of chylothoraces with conservative treatment. Thoracentesis and closed thoracostomy tube drainage may be used both to establish the diagnosis and treat the symptoms. Resolution presumably occurs after adequate enlargement of collateral vessels, reduction of lymph pressure, and reabsorbtion of extravasated chyle. REFERENCES 1. Stuart WJ. Operative injury of the thoracic duct in the neck. Edinburgh Med J 1907;22:301-317. 2. Frazell EL, Harrold CC, Rasmussen L. Bilateral chylothorax. Ann Surg 1951;134:135-137. 3. Coates JL, Desanto LW. Bilateral chylothorax as a complication of radical neck dissection, d Laryngol Otolaryngol 1976; 90:967-970. 4. Saraaceno CA, Farrior RT. Bilateral chylothorax, a rare complication of neck dissection. Arch Otolaryngol 1981;107:497499. 5. Har-E1 G, Segal K, Sidi J. Bilateral chylothorax complicating radical neck dissection: Report of a case with no concurrent external chylous leakage. Head Neck Surg 1985;7:225-230. 6. Ng RS, Kerbavaz ILl, Hilsinger RL. Bilateral chylothorax from radical neck dissection. Otolaryngol Head Neck Surg 1985; 93:814-817. 7. Pace-Balzan A, Moriarty B. Bilateral chylothorax following left radical neck dissection. J Laryngol Otolaryngol 1988;102: 288-290. 8. Laaveg SJ, Spraque BL Traumatic chylothorax, a complication of fracture dislocation of the spine. J Bone Joint Surg 1978;60A:708-709. 9. Dulchavsky SA, Ledgerwood AM, Lucas CE. Management of chylothorax after blunt chest trauma. J Trauma 1988;28: 1400-1401. 10. Robinson CLN. The management of chylothorax. Ann Thorac Surg 1985;39:90-95. 11. Birt AB, Connolly NK. Traumatic chylothorax: A report of a case and a survey of the literature. Br J Surg 1951;39:564568. 12. Fitz-Hugh SG, Cowgill R. Chylous fistula: Complication of neck dissection. Arch Otolaryngol 1970;91:543-547. 13. Lee FC. The establishment of collateral circulation following ligation of the thoracic duct. Bull Johns Hopkins Hosp 1922;33:21-31.
Case reports
395
14. Blalock A, Robinson CS, Cunningham RS, et al. Experimental studies on lymphatic blockage. Arch Surg 1937;34:10491071. 15. Lee FC. Permeability of lymph vessels and lymph pressure. Arch Surg 1944;48:35%365. 16. Schuknan A, Fataar MB, Dalrymple R, et al. The lymphographic anatomy of chylothorax. Br J Radiol 1978;5t:420427. 17. Selle JG, Snyder WH, Schreiber JT. Chylothorax: Indications for surgery. Ann Surg 1973;177:245-249. 18, Teba L, Dedhia HV, Bowen R, et al. Chylothorax review. Crit Care Med 1985;13:49-52. 19. Klepser RG, Berry JE. The diagnosis and surgical management of chylothorax with aid of lipophilic dyes. Dis Chest 1954;25:409-426. 20. Staats BA, Ellefson RD, Budahon LL, et al. The lipoprotein profile of chylous and nonchylous pleural effusions. Mayo Clin Proc 1980;55:700-704. 21. Denborough MA, Nestel PJ. Milky effusions. Med J Aust 1964;2:874-876. 22. Seriff NS, Cohen PS, Samuel P, et al. Chylothorax: Diagnosis by llpoprotein electrophoresis of serum and pleural fluid. Thorax 1977;32:98-100. 23. Bozzetti F, Arullani A, Baticci F, et al. Management of lymphatic fistulas by total parenteral nutrition. J Parenteral Nutr 1982;6:526-527. 24. Engevik L. Traumatic chylothorax. Scand J Thorac Cardiovasc Surg 1976;10:77-78. 25. Ramos W, Faintuch J. Nutritional management of thoracic duct fistulas. A comparative study of parenteral versus enteral nutrition. J Parenteral Nutr 1986;10:519-521. 26. Hashim SA, Roholt HD, Babayan VK, et al. Treatment of chyluria and chylothorax with medium-chain triglyceride. N Engl J Med 1964;270:756-761. 27. Breaux J, Marks C. Chylothorax causing reversible T-cell depletion. J Trauma 1988;28:705-707. 28. Milsom JW, Kron IL, Rheuban KS, et al. Chylothorax: An assessment of current surgical management. J Thorac Cardiovasc Surg 1985;89:221-227. 29. Ferguson MK, Little AG, Skinner DB. Current concepts in the management of postoperative chylothorax. Ann Thorac Surg 1985;40:542-545. 30. Cavallo CA, Hirata RM, Jaques DA. Chylothorax complicating radical neck dissection. Ann Surg 1975;41:266-268. 31. Thurer RJ. A complication of subclavian vein catheterization and parenteral hyperalimentation. J Thorac Cardiovasc Surg 1976;71:465-468. 32. Dhande V, Kattwinkel J, Slford B. Recurrent bilateral pleural effusions secondary to superior vena cava obstruction as a complication of central venous catheterization. Pediatrics 1983;72:109-113.