Chylothorax can occur after any surgery performed in the vicinity

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1 Alaa Basiouni S et all Chylothorax after surgery for congenital heart disease in children: a retrospective observational study Alaa Basiouni S MD Sameh Ibrahim MD Background: Chylothorax in children after pediatric cardiac surgery heart is a clinical challenge. This study reviews our experience in the management of chylothorax following surgical repair of congenital heart disease in children. Methods: A retrospective analysis of 40 patients with a median age of 10 months (range, months) who developed chylothorax after congenital heart surgery (July 2007 through January 2010). Data were collected regarding demographics, surgical procedures, characteristics of chylous drainage and its management. The responses of patients to different lines of treatment were recorded. Results: There was no hospital death. All patients were treated by Fat-free diet or medium chain triglyceride (MCT)-enriched diet mainly Monogen. Steroids were used adjunctively in seven patients (17.5%). Somatostatin analogous (octreotide) was used adjunctively in five patients (12.5%), and in two patients (5%) steroids and octreotide were used adjunctively. The median duration of chest tube drainage was 9.5 days (range, 4-34 days). The median amount of chest tube drainage /kg/ day was 17mL (range, 6.6 to 70 ml). All patients responded to medical treatment except one case required further thoracic duct ligation. The use of octreotide and steroids therapy significantly reduced the amount of chest tube drainage. None developed major side effects from steroids or octreotide. At median follow up of 7 months (range, 1-24 months) after hospital discharge, no recurrence of chylothorax was observed. Conclusions: Conservative therapy of chylothorax after surgical repair of congenital heart disease remains the standard approach. Steroids and or octreotide can be used with an acceptable success with no recurrence or mortality. Addrees reprint request to : Dr. Alaa Basiouni Said Mahmoud. King Faisal Specialist Hospital and Research Center. Cardiothoracic surgery dept. MBC J 16 P.O.Box Jeddah Saudi Arabia. alaabasiouni@hotmail.com Codex : 05/127/1010 Chylothorax can occur after any surgery performed in the vicinity of the thoracic duct including surgical repair of congenital heart disease. The incidence of chylothorax following cardiothoracic surgery has increased from % up to 6.6% over the past 20 years (1-9). This increase almost certainly reflects the increased complexity of cardiac surgery with a higher incidence of chylothorax observed following the Fontan procedure, bidirectional Glenn shunt and tetralogy of Fallot repair (5,7). The consequences of a persistent chylous leak may be serious, including nutritional depletion with lipid and protein loss, compromise of immune system from the loss of immune proteins and lymphocytes, electrolyte and weight loss (1-5). Chylothorax also may lead to increased hospital stay and mortality. Diagnosis of chylothorax relies on the presence of chylomicrons, triglyceride level above 1.1 mmol/l, and an absolute white blood cell counts above 1,000 cells/mm3, with a lymphocyte fraction above 80% in the pleural fluid(6,7,10). One of the challenges of managing this complication, especially in neonates and small infants, is to maintain fluid, 76 The Journal of Egyptian Society Cardiothoracic Surgery Jul - dec 2010

2 Alaa Basiouni S et all electrolyte, and nutritional homeostasis while trying to eliminate the lymphatic leak using therapies that are often lengthy. Nutritional support and strategies to limit the volume and duration of chylous loss provide the key to limit complications of chylothorax. A somatostatin analog (octreotide) and steroids have been used in addition to nutritional modifications with acceptable successes rate (11-16). The aim of this study was to review our experience and current approach in the management of chylothorax in children following surgical repair of congenital heart surgery. It also aimed at evaluation of the effects of fatfree diet, steroids and octreotide in its treatment. Methods: This is a retrospective analysis of all pediatric patients who developed chylothorax after surgical repair of congenital heart disease (July 2007 through January 2010) in our hospital. The demographic, operative, intensive care unit, dieticians records, and ward data were collected. Serial data from the hospital stay were recorded including dietary intake, laboratory investigations, medications and chest tube drainage. Interval between surgery and chylothorax diagnosis were recorded. Diagnostic criteria for chylothorax were applied as reported in the literature (6, 7, 10). Namely, triglyceride level above 1.1mmol/L and an absolute white blood cell counts above 1,000 cells/mm3, with a lymphocyte fraction above 80%. Patients were divided into 4 groups according to the line of treatment. Group (1); was treated by only dietary modification using fat-free diet and or monogen(scientific hospital supplies, Liverpool, England); group (2); was treated with dietary modification and octreotide, group (3); treated was with dietary modification and steroids, and group (4); was treated with dietary modification and both steroids and octreotide. Hospital death was defined as death occurring from the intraoperative period up to 30 days after surgery. Outpatients charts were accessed to determine patient status with regard to recurrent effusions. Recurrences were defined as re-accumulation of chylothorax after initial chylothorax resolution and hospital discharge. Statistical analysis : Statistical analysis was performed with SPSS statistical program (SPSS 15 Inc., Chicago, Illinois). Data were presented as mean or median with ranges or percentages as appropriate. Differences in categorical variables were analyzed by means of the χ2 analysis, and differences in continuous variables were analyzed by Student t tests. The Fisher exact test was also used where appropriate. Differences were considered to be statistically significant when p value was less than Results: Patients Demographics Patients characteristics and procedures are listed in Table1. During the period of the study, 40 patients were identified to have postoperative chylothorax from a total of 755 congenital heart surgeries, giving an incidence of 5.2%. There were 21 females and 19 males. The median age at repair was 10 months (range, months) and the median weight was 6 kg (range kg). Thirteen patients (32.5%) had single-ventricle morphology and redo surgeries were done in 11 (27.5%) patients (10 single ventricle and one biventricular repair). Surgical procedures preceding the occurrence of chylothorax included tetralogy of Fallot repair in 8 patients (20%), complete atrioventricular canal repair in 8 patients (20%), Extra cardiac Fontan procedure in 5 (12.5%) Bidirectional Glenn shunt in 5 (12.5%), arterial switch repair in 3 (7.5%), total anomalies pulmonary venous drainage in two (5%), Blalock-Taussig shunt in 3, ventricular septal defect in 3 (7.5%), ventricular septal defect status post pulmonary artery banding in one (2.5%), and Rastelli operation in 2 (5%). Chest tube drainage was determined from the daily charts. The duration and the amount of drainage/kg/day were calculated for every patient. For the purpose of the study, the duration of chylothorax was considered from the date of surgery until chest tube removal regardless when the chemical diagnosis of pleural fluid was obtained. Resolution of chylothorax was defined as chest tube drainage of less than 5 ml/kg/day Operative data: Surgical approach was by median sternotomy in all cases. Our hospital preference is to remove the thymus gland for exposure in all patients. Both pleurae were opened routinely and drained at the end of the operation. The chest was usually drained through one or two Silastic Blake drain (Ethicon, Inc) with a single pleur-evac system. The median cardiopulmonary bypass time was 105 minutes (range, minutes) and the median aortic cross clamp time was 82 minutes (range, minute). The Journal of Egyptian Society Cardiothoracic Surgery Volume 18, Number (3-4) 77

3 Alaa Basiouni S et all Variable n=40 Median age at repair (months) 10 months (range, 1-120) Male/female 19/21 Median weight at repair (kg) 6 kg (range, ) Cardiac anatomy (No. %) Single ventricle anatomy 13 (32.5%) Biventricular anatomy 27 (67.5%) Redo surgeries 11 (27.5%) Operation (No. %) Complete atrioventricular canal repair 8 (20%) Tetrology of Fallot repair 8 (20%) Fontan 5 (12.5%) Bidirectional Glenn 5 (12.5%) Blalock-Taussig shunt 3 (7.5%) Ventricular septal defect repair 3 (7.5%) Ventricular septal defect, S/P 1 (2.5%) pulmonary artery banding Total anomalies pulmonary 2 (5%) venous connection repair 3 (7.5%) Arterial switch repair Rastelli operation 2 (5%) Table 1. Patients characteristics and procedures Diagnosis of chylothorax: The diagnosis of chylothorax was suspected when persistent chest tube drainage occurred or the drainage from the chest tube became cloudy in orally fed patients regardless of the volume. Diagnosis was confirmed based on biochemical and microscopic analyses of the pleural fluid for each patient. Diagnosis of chylothorax was confirmed from laboratory testing of the fluid collected in the chest tube. All patients had at least one of the 4 previuosly mentioned parameters used for its diagnosis. The median triglyceride content in the pleural fluid was 1.4 mmol/l (range, mmol/l). Six patients (15 %) had triglyceride level less than 1.1 mmol/l. thirtytwo patients (80%) had white blood cell counts above 1000 cells/mm3with a percentage of lymphocytes above 80 % in 27 of them. postoperative chylothorax. All patients were treated initially with dietary modification beginning with fatfree or Monogen with subsequent nothing by mouth and total parenteral nutrition. In addition to fat-free diet, diuresis and after load reduction by Angiotensin converting enzyme (ACE) inhibitors were maximized to lower ventricular end-diastolic pressure. Supplement of concentrated albumin, electrolytes were also added as required. If chest tube drainage continued for more than 7-10 days octreotide or steroids were induced. There was no fixed protocol for the use of octreotide and steroids. Dosing and duration of these drugs were based on the surgeon preference. Twenty-six patients (65%) were treated only with fat-free and or Monogen diet (group 1), octreotide was used adjunctively in 5 (12.5%) patients (group 2), steroids were used adjunctively in 7 (17.5%) patients (group 3), and in two patients (5%) both octreotide and steroids were used adjunctively (group 4). Chylothorax fluid characteristics for the whole series (Table 2) There was no hospital mortality. For the whole group, median time to diagnosis of chylothorax was 3 days (range, 1-7 days) after surgery, the median amount of chest tube drainage/kg/day was 17 ml (range, ml), and the median duration of chest tube drainage was 9.5 days ( range 4-34 days). Outcomes of chylothorax Management in the 4 groups (table3) All patients except one (2.5%) responded to conservative therapy with resolution of chylothorax. This patient was a 2 year old boy with double outlet right ventricle with hypoplastic right ventricle who had a redo sternotomy and bidirectional Glenn shunt status post Blalock-Taussig shunt. Postoperatively, his mean chest tube drainage was 17ml/kg/day. Monogen was started for 10 days, followed by steroids for 5 days. However, the chest tube drainage did not improve. It was planned to keep him nothing by mouth and to start total parenteral nutrition. After two days the plan was changed because of the non compliance of the mother who kept on giving the patient milk formula. At the end, right thoracotomy and supra-diaphragmatic ligation of the thoracic duct on the 23rd day postoperatively was performed. The chest tube was removed on the 6th day post duct ligation. Management of chylothorax after diagnosis: During the period of this study, there was no standardized protocol for the management of Twenty six patients (65%) responded to lone fat-free diet and or Monogen. The median chest tube drainage was 16.6 ml/kg/day in group 1, 11.5 in group 2 and The Journal of Egyptian Society Cardiothoracic Surgery Jul - dec 2010

4 Alaa Basiouni S et all Variable Median Time to diagnose chylothorax (days) Median Triglyceride level (mmol/l) Triglyceride more than 1.1 mmol/l White blood cells count above 1000 cells/mm3 (n=40) Lymphocytes above 80% (n=32) Median amount of chest tube drainage/ kg/day (ml) Median duration of chest tube drainage (days) Median ICU stay for the whole series (days) Median hospital stay for the whole series (days) Lines of treatment of chylothorax (No. %) Group 1 (Dietary modification) Group 2 (Dietary modification + steroids) Group 3 (Dietary modification + octreotide) Group 4 (Dietary modification + steroids+octreotide) 3 (range, 1-7) 1.4 (range, ) 34 (85%) 32 (80%) 27 (84%) 17 (range, ) 9.5 (range, 4-34) 4 ( range, 2-47) 15 (range, 8-60) 26 (65%) 7 (17.5%) 5 (12.55%) 2 (5%) Table 2. Characteristics of Chylothorax and chest tube drainage and hospital stay. Dietary modification= fat-free and or Monogen Lone Fat-Free n=26 Fat-Free + Octreotide n=5 Fat-Free + Steroids n=7 Fat-Free+ Steroids+Octreotide n=2 Time to diagnose chylothorax (days) Mean Chest tube drainage/kg (ml)/day in the 1st week Mean Chest tube drainage/kg (ml)/day after 1st week Mean duration of chest tube drainage (days) after the start of each treatment ICU Stay Hospital stay Failure Recurrence Table 3. Results of the 4 groups. The Journal of Egyptian Society Cardiothoracic Surgery Volume 18, Number (3-4) 79

5 Alaa Basiouni S et all in group 3 and 16.2 in the group 4. The median duration of chest tube drainage was 18, 14.5, 13 and 15.5 days in the 4 groups respectively. The hospital stay was significantly longer in the groups 2, 3 and 4 (21, 27 and 30 days than in group 1(21.3 days) with p values of 0.04, 0.02 and 0.04 respectively It was noted that the use of octreotide and steroids had a positive impact on reducing the amount of chest tube drainage/day (Figures 1 and 2). In the octreotide group, the mean indexed daily drainage was decreased from 18.6 to 10.1 ml/kg/day with p value of Similarly the use of steroids decreased the mean indexed daily drainage from 16.2 to 10.1 ml/kg/day with p value of Follow-up Follow-up was available for all cases except 2 patients who were living outside the country. In all patients, Parents were instructed to stay on the MCTenriched diet for 4-6 weeks. At the time of follow up, most of the patients were switched to a normal diet appropriate for their age. There was no reaccumulation of chylous effusion (by Chest X-ray) in any patient during a median follow up of 7 months (range, 1-24 months). Discussion: Incidence and etiology of chylothorax Chylothorax after pediatric cardiac surgery is not uncommon with a reported incidence of 0.6% to 6.6% and can cause significant morbidity and mortality (1-9) Figure (1): Octreotide use on day 18 postoperatively, patient s weight 24 kg Figure (2): Steroids use on day 15 postoperatively patient s weight 37.5 kg. Chest tube management Our hospital preference has been to place chest tube to suction during the medical management phase. Suction was turned off for 24 hours before chest tube removal. Chest X-ray was done in all patients before removal of chest tube to exclude residual collection in the pleural cavity We are reporting here 40 cases out 755 cases of pediatric cardiac surgeries in our tertiary centre with an incidence of 5.2%. The chylothorax incidence rate of 5.2% for a 30 months period in our study is higher than in previous older studies reporting incidence less than 2 % (1-4). This change likely reflects differences in the characteristics of patients, types of surgical procedures and time frame of these studies. Chylothorax after surgery for congenital heart disease may be attributed to disruption of accessory small lymphatic channels, direct thoracic duct injury, and elevated pressure in the upper body systemic veins exceeding that in the thoracic duct (16). In our study, all patients had undergone sternotomy, and surgical manipulation was remote from the course of the thoracic duct. The high incidence of chylothorax in our study is not clear but may be due to our practice of removal of the thymus gland for better exposure which might lead to chyle leaking from its remnant. Injury to small lymphatic vessels around the ascending aorta, superior vena cava, or the pulmonary artery trunk and its branches, can occur leading to lymph leakage. Another explanation may be due to the common variation in the lymphatic pathways may render them vulnerable to injury during extensive dissection especially in redo surgery, 11 patients (27.5%) in our study. The high central systemic venous pressure can result in obstruction to the flow of lymph into the venous system, leading to dilatation and possibly rupture of small thoracic duct branches with subsequent lymphatic leak into the pleural cavity(2). In particular, the Fontan, bidirectional Glenn shunt and right ventricular dysfunction after repair of tetralogy of Fallot are associated with a high risk of developing high 80 The Journal of Egyptian Society Cardiothoracic Surgery Jul - dec 2010

6 Alaa Basiouni S et all central venous pressure. In our study, these operations were performed in 45 % of our patients. Diagnosis of chylothorax Diagnostic criteria for pediatric chylothorax have been defined by many authors (6,7,10, 17, 18). Our practice is to send for chyle study if the nature of fluid is suspicious (large amount, milky). We used the criteria of triglyceride concentration above 1.1 mmol/l, total white blood cell counts above 1,000 cells/mm3, with a percentage of lymphocytes above 80% (6,7,10). Cholesterol level is not applicable in neonates and infants as dietary fat used in their formula consists mainly of triglycerides and almost no cholesterol, and the presence of cholesterol in the effusion is not expected (10). In our study, 85% of the patient samples had triglyceride levels more than 1.1 mmol/l. Poor enteral nutrition at the time of sending samples may explain the low triglyceride level in the rest of the patients. Management of chylothorax Treatment of chylothorax has historically proceeded in a stepwise fashion once adequate drainage has been established (7). The primary aim is to drain the pleural effusion and stop or decrease the thoracic lymph flow to allow the thoracic duct branches to heal. The first line conservative therapy is based on decreasing lymph flow by nutritional modification in the form of fat-free (19) or low-fat, preferably MCT-enriched diets as Monogen (6). If chyle production does not decrease with dietary restriction, a period of gut rest and total parenteral nutrition is imposed. Pharmacologic therapy may most commonly octreotide (11-15) or steroids (20-21) may provide a medical option with a high success rate reported in several studies. If this conservative treatment fails, the next step will be surgical intervention in the form of pleurodesis (22), ligation of the thoracic duct (23) or pleuroperitoneal shunt (24). In our study the first step of management was keeping chest tube on suction. Continuous suction drainage helps to relieve the pressure of chyle on the lungs, re-expands the partially collapsed lungs, obliterates the pleural space, and permits an accurate measurement of chyle production. Our approach was to start with Monogen for young babies and fat-free diets for older infants and children. In a week to 10 days, if the chest tube drainage trend is still high, going up or not decreasing to about 5 ml/kg/day, we start another line of management, either steroids 1-2 mg/kg/day on 2 divided doses or octreotide (5-10 mcg/ kg/h) intravenously for 5-10 days with gut protection for steroids with proton pump inhibitor and blood pressure monitoring for octreotide. The role of MCT-enriched diet in chylothorax In our study, most patients (26 of 40, 65%) had successful resolution of their drainage with only using fat-free diet and Monogen. MCT-enriched diet constitutes little to chylomicrons formation and so should minimize the volume of lymph flow along the thoracic duct allowing time for healing of the thoracic duct branches. The MCT diets have met with variable success in the treatment of chylothorax. This is may be because any oral enteral feeding increases lymph flow (25), and intestinal triglycerides are derived from both endogenous and exogenous sources (26). Our practice is to avoid total parenteral nutrition and long term central lines, as much as possible, for 4 reasons. The first reason is there is always a concern about thrombus formation especially after bidirectional Glenn and Fontan procedures. The second reason is that chylothorax is an annoying problem for patients and parents. It is difficult for the patient and the parents to keep patient on nothing by mouth for 1-2 weeks especially in children. The compliance of the patient and the parents is usually poor. The third reason is that enteral feeding will protect gut barrier function through the provision of luminal nutrients. The fourth reason is that no difference in clinical outcome has been reported between patients receiving an MCT-enriched diet when compared with parenteral nutrition (1,4, 7). The role of octreotide in chylothorax In our study, octreotide was used in 5 patients (12.5%) and had a positive impact on reducing chest tube drainage with final resolution of chylothorax. Octreotide was safe and only minor side effects were documented in the files in the form of transient abdominal distension and loose stool. However, during administration of octreotide, regular monitoring of liver function, blood glucose and thyroid function test is recommended (15). Octreotide is the synthetic analog of somatostatin with a longer half-life and is available for use either intravenously or subcutaneously (27). Since the first reports of its use in the 1990 (27,28), somatostatin and octreotide have been recommended for the treatment of chylothorax prior to surgical interventions for prolonged chylous drainage not responding to conservative The Journal of Egyptian Society Cardiothoracic Surgery Volume 18, Number (3-4) 81

7 Alaa Basiouni S et all nutritional management (11-16). The optimal timing of initiating octreotide in addition to dietary measures has not been clearly defined yet. The mechanism of action of octreotide in the reduction of chylothorax is not well understood although it may occur via the reduction of the gastrointestinal blood flow, lymphatic flow and inhibiting intestinal motility. It has been also proposed that lymphatic vessels may contain somatostatin receptors that respond by reducing lymph production (29) or reduce absorption of triglycerides from the gut (30). Octreotide is usually commenced at 0.5mcg/kg/h and gradually increased to a maximum dose at 10 mcg/ kg/h (15). In the majority of studies, the treatment effect of octreotide was evident by 5 6 days, with the median duration of therapy reported from days (11-16). If the treatment is not successful, the infusion should be gradually reduced over a 3-day period (15). The role of steroids in Chylothorax In our study, steroids were used in 7 patients (17.5%) and also had a positive impact on reducing chest tube drainage with final resolution of chylothorax in six out of them. Success with steroid therapy has been reported in case reports of chronic pleural effusion following the Fontan procedure and in association with specific medical conditions (20,21). Although there is no sufficient evidence to support the use of steroids in the routine management of post-operative chylothorax, they have been used with no clear mechanism to explain how this may resolve a lymphatic leak and no definitive guidelines for dosing exist. However, endogenous glycocorticosteroids are known to reduce the quantity of protein in the tissues with increasing the degradation rate of extrahepatic proteins. Amino acids that are released will increase hepatic protein synthesis. The increased of the plasma s osmotic pressure causes the immediate shift of the fluids from the interstitial tissue to the blood, reducing the volume of lymph (31). Failure of conservative treatment and hospital mortality We encountered only one failure (2.5%) of the conservative treatment. One out of the 7 patients who were treated with fat-free diet and steroids continued to have high amount of chest tube drainage. Hyperalimentation could not be continued due to lack of compliance. He had a successful thoracic duct ligation with complete resolution of chylothorax. No mortality related to chylothorax in our study probably due to early diagnosis and aggressive treatment and better patient characteristics than other reports (23,28). Recurrence of chylothorax We did not encounter any recurrence in our study. This may be due to the relatively short follow up duration (median of 7 months). However the longest follow-up was 24 months with no reccurence. Conclusions: Based on our results, in the absence of contraindications to enteral feeding, an initial trial of enteral feeding using fat-free diet and or Monogen and if the response is not appropriate octreotide and or steroids can be used safely. Controlled randomized clinical trials should be conducted to evaluate whether earlier introduction with steroids or octreotide can reduce hospital duration and improve prognosis of chylothorax following pediatric heart surgery. Limitations: This is a retrospective study with a relatively small number of patients. There are some significant differences in the complexity of operations and treatment regimens. Follow-up was relatively short. There was no standard fixed protocol for the management of each patient in this series. References 1. Allen E, Van Heeckeren D, Spector M, Blumer J. Management of nutritional and infectious complications of postoperative chylothorax in children. J Pediatr Surg 1991; 26: Le Coultre C, Oberhansli I, Mossaz A, Bugmann P, Faidutti B, Belli D. Postoperative chylothorax in children: Differences between vascular and traumatic origin. J. Pediatr. Surg. 1991; 26: Bond S, Guzzetta P, Synder M, Randolph J. Management of pediatric postoperative chylothorax. Ann Thorac Surg 2001; 72: Nguyen D, Shum-Tim O, Dobell A, Tchervenkov C. The management of chylothorax/chylopericardium following pediatric cardiac surgery: a 10-year experience. J Card Surg 1995; 10: Beghetti M, La Scala G, Belli D, Bugmann P, Kalangos A, Le Coultre C. Etiology and management of pediatric chylothorax. J Pediatr 2000; 136: Cormack B, Wilson N, Finucane K, West C. Use of Monogen for pediatric postoperative chylothorax. Ann Thorac Surg 2004; 77: Chan E, Russell J, Williams W, Van Arsdell G, Coles J, McCrindle B. Postoperative chylothorax after cardiothoracic surgery in children. Ann Thorac Surg 2005; 80: Cannizzaro V, Frey B, Bernet-Buettiker V. The role of Somatostatin in the treatment of persistent chylothorax in children. Eur J Cardiothorac Surg 2006; 30: The Journal of Egyptian Society Cardiothoracic Surgery Jul - dec 2010

8 Alaa Basiouni S et all 9. Milonakis M, Chatzis A, Giannopoulos N, Contrafouris C, Bobos D, Kirvassilis G, Sarris G. Etiology and management of chylothorax following pediatric heart surgery. J Card Surg 2009; 24: Buttiker V, Fanconi S, Burger R. Chylothorax in children: Guidelines for diagnosis and management. Chest 1999; 116: Pratap U, Slavik Z, Ofeo V, Onuzo O, Franklin R. Octreotide to treat postoperative chylothorax after cardiac operations in children. Ann Thorac Surg 2001; 72: Cheung Y, Leung M, Yip M. Octreotide for treatment of postoperative chylothorax. J Pediatr 2001; 139: Milkroulis D, Didilis V, Bitzikas G, Bougioukas G. Octreotide in the treatment of chylothorax. Chest 2002; 121: Rosti L, Bini R, Chessa M, Butera G, Drago M, Carminati M. The effectiveness of octreotide in the treatment of postoperative chylothorax. Eur J Pediatr 2002; 161: Lim K, Kim S, Huh J, Kang I, Lee H, Jun T, Park P. Somatostatin for Postoperative Chylothorax after Surgery for Children with Congenital Heart Disease. J Korean Med Sci 2005; 20: Chan S, Lau W, Wong W, Cheng L, Chau A, and Cheung Y. Chylothorax in Children after Congenital Heart Surgery. Ann Thorac Surg 2006; 82: Staats B, Ellefson R, Budah L The lipoprotein profile of chylous and nonchylous pleural effusion. Mayo clinic Proc 1980; 55: Straaten Van H, Gerards L, Krediet T. Chylothorax in the neonatal period. Eur J Pediatr 1993; 152: Gershanik J, Jonson H, Riopel D. Dietary management of neonatal chylothorax. Pediatrics 1994: 53: 15: Rothman A, Mayer J, Freed M. treatment of chronic pleural effusions after the Fontan procedure with prednisolone. Am j Cardiol 1987; 60: Patsouras D, Argiri O, Sideris D. Spontaneous Chylothorax in a Patient with Noonan Syndrome: Treatment with Prednizone. Hellenic J Cardiol 2002; 43: Rubin J, Moore H, Ellison R. Chylothorax: Therapeutic alternatives. Am Surg 1977; 43: Nath D, Savla J, Khemani R, Nussbaum D, Greene C, Wells W. duct ligation for persistent chylothorax after pediatric cardiothoracic surgery. Ann Thorac Surg 2009; 88: Wolff A, Silen M, Kokoska E, Rodgers B. Treatment of refractory chylothorax with externalized pleuroperitoneal shunts in children. Ann Thorac Surg 1999; 68: Robinson C. The management of chylothorax. Ann Thorac Surg 1985; 39: Shiau Y, Popper D, Reed M, Omstetter C, Capuszzi D, Levine G. Intestinal triglycerides are derived from both endogenous and exogenous sources. Am J Physiol 1985; 248: Lamberts S, Vander Ley A, De Herder W, Hofland L. Octreotide. N Engl J Med 1966; 334: Rimensberger PC, Muller-Schenker B, Kalangos A, Beghetti M. Treatment of a persistent postoperative chylothorax with somatostatin. Ann. Thorac. Surg 1998; 66: Scarpignato C, Pelosini I. Somatostatin for upper gastrointestinal hemorrhage and pancreatic surgery. A review of its pharmacology and safety. Digestion 1999; 60 (Suppl. 3): Hengl G, Prager J, Pointner H. The influence of somatostatin on the absorption of triglycerides in partially gastrectomized subjects. Acta. Hepatogastroenterol. 1979; 26: Guyton AC: Textbook of Medical Physiology. Philadelphia, Pa: WB Saunders Co;1991, p 769. Quoted from Patsouras et al., reference (21). The Journal of Egyptian Society Cardiothoracic Surgery Volume 18, Number (3-4) 83