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Postoperative chylous pseudocyst
Postoperative chylous pseudocyst A 59-year-old man underwent resection of an aneurysm of the descending thoracic aorta with graft replacement. A postoperative chylothorax was managed by nonsurgical means and subsided. Subsequently, an expansile mass appeared in the left side of the chest and was surgically removed. This was found to be a chylous pseudocyst. Management of chylothorax and the details of this unique case are described.
John W. Mack, Major, USAF (MC), William H. Heydom, Colonel, MC, USA, Fred W. Pauling, Colonel, MC, USA, and Maurice E. Lindell, Colonel, MC, USA, Presidio of San Francisco. Calif.
Intraoperative injury to a thoracic duct system resulting in chylothorax occurs in only 0.2 to 0.5 percent of intrathoracic procedures.t" Chylothorax typically follows an operation for correction of congenital cardiovascular anomalies in infants and small children but has been reported in all age groups after a variety of thoracic operations.": 2 •.';-7 This condition usually occurs from the second to the tenth postoperative days but may be delayed for several months.f Recurrences after cessation of leakage have been reported.v 8 There may be a rapid accumulation of chyle in the pleural cavity from an opening in the thoracic duct or one of its main tributaries. Higgins and Mulder have reported several cases of chyloma in which there was progressive enlargement of the cardiomediastinal shadow on chest roentgenogram owing to accumulation of chyle in the mediastinum and eventually rupture of chyle intrapleurally. We recently treated a patient in whom chylothorax occurred after resection of an aneurysm from the descending thoracic aorta. Nonsurgical therapy resulted in resolution of the chylous drainage, but subsequently a large mass developed in the left side of the chest. At operation this was found to be a chylous pseudocyst. We were unable to find a similar case in From the Thoracic and Cardiovascular Surgery Service. Department of Surgery, Letterman Army Medical Center, Presidio of San Francisco, Calif. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. Received for publication Oct. 6, 1978. Accepted for publication Nov. IS, 1978. Address for reprints: Technical Publications Editor, Letterman Army Medical Center, Presidio of San Francisco, Calif. 94129.
Fig. l. Chest roentgenogram showing a mass along the left heart border. the literature and are reporting this case with emphasis on precipitating factors, diagnosis, and management.
Case report In November, 1976, a 59-year-old black man underwent resection and Dacron graft replacement of a saccular aneurysm of the descending thoracic aorta while supported by partial cardiopulmonary bypass. The operation was uncomplicated. Postoperatively, chest tube drainage was normal until the fifth postoperative day, when chylous material began draining at a rate of 200 to 300c.c. per day. Oral feeding was discontinued in favor of total parenteral nutrition. By the seventh postoperative week, the volume of chest tube drainage had decreased to the point that the patient was allowed an oral diet, whereupon the volume again increased. Feedings were again withheld and parenteral nutrition was resumed for an additional 2 weeks, after which time drainage ceased, chest tubes were removed, and hyperalimentation was discontinued. Ten days after removal of the chest tubes, roent-
773
774 Mack et al ,
The Journal of Thoracic and Cardiovascular Surgery
Fig. 2. Aortogram showing an intact graft and no false aneurysm . genograms showed a left pleural effusion and enlargement of the left cardiomediastinal border (Fig. I). An aortogram ruled out a false aneurysm (Fig. 2). A severe vesicular skin rash developed, felt to be bullous pemphigoid, for which the patient was treated with systemic steroids. The severity of the skin disease and lack of chest symptoms prompted us to watch this gradually enlarging chest mass without recommending surgical intervention. The mass was thought to represent a chyloma or chylous cyst. Nine months after the operation, the mass appeared stable (Fig. 3), but the patient was having shortness of breath and pressure in the left side of the chest. A computerized axial tomographic scan showed a large cystic mass in the posterior mediastinum enveloping the aorta (Fig. 4). Steroids were gradually decreased and in July, 1978, a left thoracotomy was performed. A large multiloculated cyst was found, which had a thick, well-organized fibrotic wall and contained chylous fluid. No feeding lymph channel was found. We unroofed the cyst but did not remove it because of its attachments to the pericardium and to the normal-appearing aortic graft. The area was drained thoroughly, and postoperatively the patient had no chylous drainage. The chest tubes were removed on the fourth postoperative day, and the patient was discharged 2 weeks after the operation doing well. The chest roentgenogram taken 6 weeks postoperatively showed no recurrence of the cyst or residual effusion (Fig. 5).
Discussion The management of traumatic chylothorax centers around four basic principles: adequate drainage of the chyle, replacement of lost fluid and metabolites , reduction of chyle flow, and surgical intervention if drainage persists . Chyle contains concentrations of protein and
Fig. 3. Chest roentgenogram 8 months after operation showing enlargement of a mass in the left side of the chest. electrolytes, which are found in plasma," and these must be replaced or protein malnutrition and electrolyte imbalance will result. Since food (especially fatty food) and fluid intake increase lymph flow through the thoracic duct, their intake should be reduced by restricting oral intake by means of either parenteral nutrition or a fat-free elemental diet. Since flow is enhanced by an increase in intrathoracic pressure or intestinal motility, it is advisable to keep the patient inactive and sedated in order to reduce flow in the thoracic duct. If conservative measures fail to control the chylous leak, an operation should be performed. Prior to Lampson's" classic description of transthoracic ligation of the thoracic duct in 1948, surgical treatment of thoracic duct fistulas was inadequate and the condition carried a mortality rate of more than 50 percent .": 10 Since that time the mortality rate has dropped dramatically and now approaches that of a thoracotomy." 6. H The indications for operation vary among different authors, mainly in regard to length of conservative treatment prior to surgical intervention . This varies from I week to I month. The criteria outlined by Selle and colleagues 10 establish guidelines for surgical management. The surgical approach in most cases is thoracic duct ligation , although attempts should be made to locate the leak . Joyce and associates recommend giving cream orally before the
Volume
n
Postoperati ve chylous pseudocyst
Number 5 May, 1979
775
Fig. 4. Computerized axial tomographic scan showing a cystic mass in the left side of the chest enveloping the aorta.
operation to increase flow in the duct and to make the chyle turbid and easier to see. Many other methods such as Iymphangiogram and dye injections have been proposed and are outlined in the review by Bessone and co-workers ." In general, the side which contains the chylothorax should be explored and , in the case of bilateral ch ylothorax, a right thoracotomy should probably be performed since access to the lower thoracic duct is easier from this side . In the ca se that we have reported there are several points to be discu ssed. The pat ient was somewhat atypical in that the amount of chylous drainage (200 to 300 c.c. per day) was much less than in most reported cases of chylothorax (l to 2 L per day).": 5. 10 This and the near cessation of drainage on several occasions caused the operation to be deferred longer than the usually recommended time . The pat ient's skin les ion s cau sed further dela y. The ultimate result was a chylous pseudocyst which probably aro se in a manner similar to a pancreatic pseudocyst. A persi stent fistula in the presence of indwelling chest tube s , which produced an intense local reaction within a confined space, most likely led to the formation of the cyst. Lack of enlargement of the cyst for a year prior to the operation suggested that the fistula had closed, as was eventually demonstrated. The indication for operation in an asymptomatic patient with a chylous pseudocyst is questionable . Since chyle is bacteriostatic and a chylothorax rarely becomes infected, prevention of secondary infection is not an indication for operation . Progressive enlargement of
Fig. 5. Chest roentgenogram showing resolution of the chest mass after surgical resection.
the cyst suggesting continued chylous leakage or impairment of pulmonary function should prompt surgical resection . In summary , a patient with a ch ylous pseudocyst who is asymptomatic , shows no enlargement of the cyst, and shows no cardiopulmonary compromise probably does not require an operation . Conversely, if any of these three factors is present, surgical intervention should be considered.
2 3 4 5 6
REFERENCES Cevese PG, Vecchioni R, D'Amico OF, Cordiano C, Biasiato R, Favia G, Farello GA: Postoperative chylothorax. J THORAC CARDIOVASC SURG 69:966-971 , 1975 Higgins CB, Mulder DG: Chylothorax after surgery for congenital heart disease. J THORAC CARDIOVASC SURG 61:411-41 8, 1971 Maloney J, Spencer F: The nonoperative treatment of traumatic chylothorax. Surgery 40:121-128 , 1956 Murphy TO, Piper CA: Surgical management of chylothorax. Am Surg 43:715 -718, 1977 Joyce LD, Lindsay WG, Nicoloff OM: Chylothorax after median sternotomy for intrapericardial cardiac surgery. J THORAC CARDIOVASC SURG 71:476 -480, 1976 Kaul TK, Bain WH, Lumer MA, Taylor KM: Chylotho-
The Journal of
7 7 6 Mack et al.
rax. Report of a case complicating ductus ligation through a median sternotomy and review. Thorax 31:610-616, 1976 7 Bessone LN, Ferguson TB, Burford TH: Chylothorax. Ann Thorac Surg 12:527-550, 1971 8 Rubin JW, Moore HV, Ellison RG: Chylothorax. Therapeutic alternatives. Am Surg 43:292-297, 1977
Thoracic and Cardiovascular Surgery
9 Lampson RS: Traumatic chylothorax. A review of the literature and report of a case treated by mediastinal ligation of the thoracic duct. J THORAC SURG 17:778-791, 1948 10 Selle JG, Snyder WH Ill, Schreiber IT: Chylothorax. Indications for surgery. Ann Surg 177:245-249, 1973
Information for authors Most of the provisions of the Copyright Act of 1976 became effective on January I, 1978. Therefore, all manuscripts must be accompanied by the following written statement, signed by one author: "The undersigned author transfers all copyright ownership of the manuscript (title of article) to The C. V. Mosby Company in the event the work is published. The undersigned author warrants that the article is original, is not under consideration by another journal, and has not been previously published. I sign for and accept responsibility for releasing this material on behalf of any and all co-authors." Authors will be consulted, when possible, regarding republication of their material.
John W. Mack, Major, USAF (MC), William H. Heydom, Colonel, MC, USA, Fred W. Pauling, Colonel, MC, USA, and Maurice E. Lindell, Colonel, MC, USA, Presidio of San Francisco. Calif.
Intraoperative injury to a thoracic duct system resulting in chylothorax occurs in only 0.2 to 0.5 percent of intrathoracic procedures.t" Chylothorax typically follows an operation for correction of congenital cardiovascular anomalies in infants and small children but has been reported in all age groups after a variety of thoracic operations.": 2 •.';-7 This condition usually occurs from the second to the tenth postoperative days but may be delayed for several months.f Recurrences after cessation of leakage have been reported.v 8 There may be a rapid accumulation of chyle in the pleural cavity from an opening in the thoracic duct or one of its main tributaries. Higgins and Mulder have reported several cases of chyloma in which there was progressive enlargement of the cardiomediastinal shadow on chest roentgenogram owing to accumulation of chyle in the mediastinum and eventually rupture of chyle intrapleurally. We recently treated a patient in whom chylothorax occurred after resection of an aneurysm from the descending thoracic aorta. Nonsurgical therapy resulted in resolution of the chylous drainage, but subsequently a large mass developed in the left side of the chest. At operation this was found to be a chylous pseudocyst. We were unable to find a similar case in From the Thoracic and Cardiovascular Surgery Service. Department of Surgery, Letterman Army Medical Center, Presidio of San Francisco, Calif. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. Received for publication Oct. 6, 1978. Accepted for publication Nov. IS, 1978. Address for reprints: Technical Publications Editor, Letterman Army Medical Center, Presidio of San Francisco, Calif. 94129.
Fig. l. Chest roentgenogram showing a mass along the left heart border. the literature and are reporting this case with emphasis on precipitating factors, diagnosis, and management.
Case report In November, 1976, a 59-year-old black man underwent resection and Dacron graft replacement of a saccular aneurysm of the descending thoracic aorta while supported by partial cardiopulmonary bypass. The operation was uncomplicated. Postoperatively, chest tube drainage was normal until the fifth postoperative day, when chylous material began draining at a rate of 200 to 300c.c. per day. Oral feeding was discontinued in favor of total parenteral nutrition. By the seventh postoperative week, the volume of chest tube drainage had decreased to the point that the patient was allowed an oral diet, whereupon the volume again increased. Feedings were again withheld and parenteral nutrition was resumed for an additional 2 weeks, after which time drainage ceased, chest tubes were removed, and hyperalimentation was discontinued. Ten days after removal of the chest tubes, roent-
773
774 Mack et al ,
The Journal of Thoracic and Cardiovascular Surgery
Fig. 2. Aortogram showing an intact graft and no false aneurysm . genograms showed a left pleural effusion and enlargement of the left cardiomediastinal border (Fig. I). An aortogram ruled out a false aneurysm (Fig. 2). A severe vesicular skin rash developed, felt to be bullous pemphigoid, for which the patient was treated with systemic steroids. The severity of the skin disease and lack of chest symptoms prompted us to watch this gradually enlarging chest mass without recommending surgical intervention. The mass was thought to represent a chyloma or chylous cyst. Nine months after the operation, the mass appeared stable (Fig. 3), but the patient was having shortness of breath and pressure in the left side of the chest. A computerized axial tomographic scan showed a large cystic mass in the posterior mediastinum enveloping the aorta (Fig. 4). Steroids were gradually decreased and in July, 1978, a left thoracotomy was performed. A large multiloculated cyst was found, which had a thick, well-organized fibrotic wall and contained chylous fluid. No feeding lymph channel was found. We unroofed the cyst but did not remove it because of its attachments to the pericardium and to the normal-appearing aortic graft. The area was drained thoroughly, and postoperatively the patient had no chylous drainage. The chest tubes were removed on the fourth postoperative day, and the patient was discharged 2 weeks after the operation doing well. The chest roentgenogram taken 6 weeks postoperatively showed no recurrence of the cyst or residual effusion (Fig. 5).
Discussion The management of traumatic chylothorax centers around four basic principles: adequate drainage of the chyle, replacement of lost fluid and metabolites , reduction of chyle flow, and surgical intervention if drainage persists . Chyle contains concentrations of protein and
Fig. 3. Chest roentgenogram 8 months after operation showing enlargement of a mass in the left side of the chest. electrolytes, which are found in plasma," and these must be replaced or protein malnutrition and electrolyte imbalance will result. Since food (especially fatty food) and fluid intake increase lymph flow through the thoracic duct, their intake should be reduced by restricting oral intake by means of either parenteral nutrition or a fat-free elemental diet. Since flow is enhanced by an increase in intrathoracic pressure or intestinal motility, it is advisable to keep the patient inactive and sedated in order to reduce flow in the thoracic duct. If conservative measures fail to control the chylous leak, an operation should be performed. Prior to Lampson's" classic description of transthoracic ligation of the thoracic duct in 1948, surgical treatment of thoracic duct fistulas was inadequate and the condition carried a mortality rate of more than 50 percent .": 10 Since that time the mortality rate has dropped dramatically and now approaches that of a thoracotomy." 6. H The indications for operation vary among different authors, mainly in regard to length of conservative treatment prior to surgical intervention . This varies from I week to I month. The criteria outlined by Selle and colleagues 10 establish guidelines for surgical management. The surgical approach in most cases is thoracic duct ligation , although attempts should be made to locate the leak . Joyce and associates recommend giving cream orally before the
Volume
n
Postoperati ve chylous pseudocyst
Number 5 May, 1979
775
Fig. 4. Computerized axial tomographic scan showing a cystic mass in the left side of the chest enveloping the aorta.
operation to increase flow in the duct and to make the chyle turbid and easier to see. Many other methods such as Iymphangiogram and dye injections have been proposed and are outlined in the review by Bessone and co-workers ." In general, the side which contains the chylothorax should be explored and , in the case of bilateral ch ylothorax, a right thoracotomy should probably be performed since access to the lower thoracic duct is easier from this side . In the ca se that we have reported there are several points to be discu ssed. The pat ient was somewhat atypical in that the amount of chylous drainage (200 to 300 c.c. per day) was much less than in most reported cases of chylothorax (l to 2 L per day).": 5. 10 This and the near cessation of drainage on several occasions caused the operation to be deferred longer than the usually recommended time . The pat ient's skin les ion s cau sed further dela y. The ultimate result was a chylous pseudocyst which probably aro se in a manner similar to a pancreatic pseudocyst. A persi stent fistula in the presence of indwelling chest tube s , which produced an intense local reaction within a confined space, most likely led to the formation of the cyst. Lack of enlargement of the cyst for a year prior to the operation suggested that the fistula had closed, as was eventually demonstrated. The indication for operation in an asymptomatic patient with a chylous pseudocyst is questionable . Since chyle is bacteriostatic and a chylothorax rarely becomes infected, prevention of secondary infection is not an indication for operation . Progressive enlargement of
Fig. 5. Chest roentgenogram showing resolution of the chest mass after surgical resection.
the cyst suggesting continued chylous leakage or impairment of pulmonary function should prompt surgical resection . In summary , a patient with a ch ylous pseudocyst who is asymptomatic , shows no enlargement of the cyst, and shows no cardiopulmonary compromise probably does not require an operation . Conversely, if any of these three factors is present, surgical intervention should be considered.
2 3 4 5 6
REFERENCES Cevese PG, Vecchioni R, D'Amico OF, Cordiano C, Biasiato R, Favia G, Farello GA: Postoperative chylothorax. J THORAC CARDIOVASC SURG 69:966-971 , 1975 Higgins CB, Mulder DG: Chylothorax after surgery for congenital heart disease. J THORAC CARDIOVASC SURG 61:411-41 8, 1971 Maloney J, Spencer F: The nonoperative treatment of traumatic chylothorax. Surgery 40:121-128 , 1956 Murphy TO, Piper CA: Surgical management of chylothorax. Am Surg 43:715 -718, 1977 Joyce LD, Lindsay WG, Nicoloff OM: Chylothorax after median sternotomy for intrapericardial cardiac surgery. J THORAC CARDIOVASC SURG 71:476 -480, 1976 Kaul TK, Bain WH, Lumer MA, Taylor KM: Chylotho-
The Journal of
7 7 6 Mack et al.
rax. Report of a case complicating ductus ligation through a median sternotomy and review. Thorax 31:610-616, 1976 7 Bessone LN, Ferguson TB, Burford TH: Chylothorax. Ann Thorac Surg 12:527-550, 1971 8 Rubin JW, Moore HV, Ellison RG: Chylothorax. Therapeutic alternatives. Am Surg 43:292-297, 1977
Thoracic and Cardiovascular Surgery
9 Lampson RS: Traumatic chylothorax. A review of the literature and report of a case treated by mediastinal ligation of the thoracic duct. J THORAC SURG 17:778-791, 1948 10 Selle JG, Snyder WH Ill, Schreiber IT: Chylothorax. Indications for surgery. Ann Surg 177:245-249, 1973
Information for authors Most of the provisions of the Copyright Act of 1976 became effective on January I, 1978. Therefore, all manuscripts must be accompanied by the following written statement, signed by one author: "The undersigned author transfers all copyright ownership of the manuscript (title of article) to The C. V. Mosby Company in the event the work is published. The undersigned author warrants that the article is original, is not under consideration by another journal, and has not been previously published. I sign for and accept responsibility for releasing this material on behalf of any and all co-authors." Authors will be consulted, when possible, regarding republication of their material.