The use of pleuroperitoneal shunts in the management of persistent chylothorax in infants

The Use of Pleuroperitoneal Shunts in the Management Chylothorax in Infants By Scott A. Engum,

Frederick

J. Rescorla,

Karen W. West, L.R. “Tres” Indianapolis,

BackgrourzrVPurpose: The development of chylothorax is a serious and often life-threatening clinical entity that may cause profound respiratory, nutritional, and immunologic complications and has become increasingly common in recent years. Optimal management of this problem has not been well defined because medical therapy has a significant failure rate. Surgical treatment of complicated chylothorax has become a mainstay of care. Methods: Over the last 36 months, seven infants had a pleuroperitoneal shunt placed for the management of refractory chylothorax. Ages ranged from 10 to 66 days with a weight between 1,000 to 4,850 g. Five of the seven infants were ventilator dependent. The etiologies were congenital in four and acquired in three with one related to a cardiothoracic procedure, one related to superior vena caval thrombosis, and one postoperative diaphragmatic hernia repair with superior vena caval thrombosis. Associated conditions included a left congenital diaphragmatic hernia, asplenia, isolated renal agenesis, bronchopulmonary dysplasia, and a patent ductus arteriosus. Each patient was unresponsive to thoracentesis, tube thoracostomy, and dietary manipulation with preoperative volume of chest tube output ranging from 50 to 162 cc/kg/d. The duration of preoperative therapy in

HYLOTHORAX in the neonate, acquired or congenital, presents a clinical challenge. Regardless of the cause, the presence of chylothorax produces respiratory compromise secondary to compression of the lung from the pleural effusion leading to progressive pulmonary insufficiency, nutritional failure, immunologic depletion contributing to sepsis, metabolic acidosis, and renal failure secondary to the loss of fats, protein, and lymphocytes. Patients initially are treated with restriction of dietary fats using total parenteral nutrition or enterally administered medium-chain triglycerides. Drainage of the pleural fluid is accomplished either by thoracentesis

C

Scherer

286

III, and Jay L. Grosfeld

Indiana

congenital occurrences ranged from 10 to 46 days (average, 22 days). A Denver double-valved shunt system was used and catheters were implanted under general anesthesia. Manual pumping was required postoperatively on an hourly basis. Results: All seven patients had excellent results with the elimination of the chylothorax and resolution of symptoms. There were two complications. Shunt survival rate was six of seven (86%). Shunt removal ranged from 24 to 79 days (average, 44 days). Patient survival rate was five of seven (71%) with one infant dying of progressive pulmonary disease and one infant dying from viral sepsis; both had functioning shunts. One patient remains ventilator dependent secondary to chronic lung disease from prematurity. Conc/usions: Pleuroperitoneal shunting is safe, simple, and an effective treatment of chylothorax in infants despite their size, age, or degree of prematurity. J Pediatr Surg 34:286-290. Copyright o 1999 by W.B. Saunders Company. INDEX WORDS neal shunt.

Chylothorax,

chylous

effusion,

pleuroperito-

or tube thoracostomy. If nonsurgical, expectant methods fail, surgical therapy is undertaken. The goal of surgical therapy is to relieve the respiratory embarrassment by draining the pleural space, allowing reexpansion of the lung, followed by minimizing the loss of the nutritional elements and immunologic cells present in the chyle. The surgical options for refractory chylothorax include chemical pleurodesis, pleurectomy, thoracotomy with thoracic duct ligation, thoracoscopy, and the use of a pleuroperitoneal shunt. This review describes the use of a pleuroperitoneal shunt in seven infants with refractory chylothorax. MATERIALS

From the Section of Pediatric Surgery, Department of Surgery, Indiana University School of Medicine and the James Whitcomb Riley Hospitalfor Children, Indianapolis, IN. Presented at 45th Annual International Congress of the British Association of Paediatric Surgeons, Bristol, Engtand, July 21-24, 1998. Address reprint requests to Jay L. Grosfeld, MD, James Whitcomb Riley Hospital for Children, 702 Barnhill DI; Suite 2.500, Indianapolis. IN 46202. Copyright 0 I999 by WB. Saunders Company 0022.3468/99/3402-0012$03.00/O

of Persistent

AND

METHODS

Patient Population Between November 1994 and December 1997, seven patients with refractory chylothorax were seen on the Pediatric Surgical Service at the James Whitcomb Riley Hospital for Children, Indianapolis, IN. They ranged in gestational age from 25 to 40 weeks, and had a birth weight of 688 to 4,300 g. The etiology of the chylothorax was congenital (idiopathic) in four and acquired in three with one seen after ligation of a patent ductus arteriosus, one secondary to superior vena caval (SVC) thrombosis after placement of a central venous catheter, and one occurring after a left congenital diaphragmatic hernia repair with

JournalofPediatric

Surgery,Vol34,

No 2 (February),

1999: pp 286-290

PLEUROPERITONEAL

SHUNTS

FOR PERSISTENT

CHYLOTHORAX

287

concurrent SVC thrombosis. Four of these infants had isolated leftsided chylous effusion, whereas three were bilateral with two affecting the right side primarily. Associated conditions included left congenital diaphragmatic hernia, bronchopulmonary dysplasia, asplenia, unilateral renal agenesis, and patent ductus arteriosus. All seven patients had aggressive pulmonary support and were treated with dietary manipulations, either initial restriction of oral fat intake to medium-chain triglyceride oil or initiation of total parenteral nutrition. The pleural space was drained either by repeated thoracentesis or tube thoracostomy. When these methods failed to relieve the flow of chyle from the chest tube or with reaccumulation of chyle within the pleural cavity, a pleuroperitoneal shunt was placed. The pleural fluid losses were between 50 and 162 ml/kg/d in these infants.

Technique In an effort to optimize pulmonary function with minimal physical injury and reduce pulmonary barotrauma while stabilizing the metabolic and nutritional status, we have used a specially designed Denver pleuroperitoneal shunt system (Denver Biomaterials, Inc, Evergreen, CO; Fig 1). The shunt is 15.5F, 60 cm long, flexible, has two polyester cuffs, a double-valved pumping chamber, fenestrated afferent and efferent catheter limbs, and can be trimmed to the appropriate lengths. The pediatric chamber has a pumping volume of 1.0 to 1.5 mL and is used for infants usually less than 6 months of age. The valves open at a positive pressure of approximately 1.0 cm Hz0 and are designed to prevent retrograde movement of the chyle through the system. Manual pumping is used to transport fluid from the pleural space into the peritoneal cavity. The technique for insertion of the shunt in infants requires general anesthesia. The affected hemithorax is elevated on the operating table. A short transverse incision is made over the affected lower chest at the anterior axillary line. This incision affords access for the pleural catheter, which is tunneled 2 to 3 cm through the subcutaneous tissues. The catheter is placed bluntly into the thorax similar to insertion of a thoracostomy tube at approximately the seventh or eighth intercostal space in the posterior axillaty line. This allows dependent drainage. Proper positioning of the catheter is critical to avoid kinking. A second small incision is made overlying the rectus muscle sheath in the upper abdomen midway between the costal margin and the level of the umbilicus. The efferent catheter is tunneled 2 to 3 cm and placed into the peritoneal cavity through the rectus incision similar to a Ten&off catheter placement, A purse-string suture is used in the posterior rectus

Fig 1. Photograph shows the pleuroperitoneal double-valved pump chamber. The end of the shortened at the surgeon’s discretion. Catheter subcutaneous placement.

shunt with the catheter can be cuffs allow for

Fig 2. (A) lntraoperative photograph illustrates a premature infant with an exteriorised valve system. Because of the infant’s small size, we elected to leave the cuffs exposed. (B) Photograph of a second infant shows the shunt catheter tunneled under the subcutaneous tissue with the cuffs buried.

fascia to secure the catheter. Before placement of the peritoneal catheter, the pumping chamber is compressed repeatedly to confirm effective pumping action and proper transport of chyle from the thorax. Because of the small size of our patient population, a large reservoir pumping chamber. and the pain and positioning problems associated with a subcutaneous reservoir system, we have elected to leave the valve system external to the infant’s body, eliminating these concerns (Fig 2). All incisions were closed in multiple layers with absorbable suture. A postoperative chest radiograph is obtained to confirm proper placement of the pleural catheter (Fig 3). During the immediate postoperative period, the pumping chamber is compressed on an hourly basis to completely clear the hemithorax of chyle. The frequency of pumping (50 to 100 compressions per hour) is necessary because of the relatively small volume delivered with each compression. As the infant’s clinical status improves; there is a gradual decrease in the frequency of reservoir compressions. Noninvasive transcutaneous oxygen saturation monitoring. arterial blood gas determination, and serial chest radiographs are used to assess effectiveness of the shunt. Once the chylous effusion clears, the parents are taught the technique of pumping the chamber, and the patient is discharged from the hospital. Over the ensuing 2 to 3 months, the frequency of pumping is reduced further, and

ENGUM

ET AL

RESULTS

All of our patients exhibited immediate improvement in pulmonary function and metabolic stability. Only one of the five ventilated patients was not weaned from the ventilator at the time of this report as a result of persistent lung disease. In two infants the pleuroperitoneal shunt functioned satisfactorily, but one patient died of viral sepsis and the other of progressive pulmonary disease. At the time of death, there was no pleural effusion noted in either child. There were no intraoperative complications, and initially all children had complete resolution of the chylous effusion. There were two late complications. The first was related to shunt malfunction with reaccumulation of chylous effusion resulting in shunt removal at 30 days postprocedure and apical pleurectomy. The second was related to cellulitis and infection at the abdominal insertion site necessitating shunt removal at 43 days postprocedure. The shunt was removed between 24 and 79 days, and averaged 44 days (Table 1). Six of seven shunts were patent and functioning at the time of discontinuation. Five of seven patients survived. One patient died of viral sepsis and a second infant died of progressive pulmonary failure, both with functioning shunts. One patient remains ventilator dependent attributed to prematurity and bronchopulmonary dysplasia. Fig 3. Postoperative chest-abdomen radiograph tion of the pleural and abdominal catheters.

shows

the posi-

DISCUSSION the catheter effusion.

is removed

if there

is no reaccumulation

Historically, chylothorax has been classified according to etiology. 1Chylothorax occurring in the neonatal period usually is categorized as either congenital (idiopathic) caused by lymphatic malformation, or acquired, which is typically postoperative. Chyle causes symptoms related to pulmonary compression.2 In the unfed neonate, the fat content of the chylothorax may be quite low and not have the characteristic “milky” appearance. Unlike a serous pleural effusion that responds to diuretic therapy and

of the chylous

Patient Characteristics at Time of Shunt Insertion Seven infants underwent placement of a pleuroperitoneal weight of 1,000 to 4,850 g. Five of the seven infants were dependent. The age at the time of shunt placement was 10 and averaged 36 days. In the congenital etiology infants, the placed at an average of 22 days of life (Table 1).

Table 1. Infants

shunt at a ventilator to 66 days shunt was

With

Chylothorax

Treated

by Pleuroperitoneal

Shunt

Case No. 1

Gestational

age (wk)

Birth weight(g) Etiology Age at time of shunt

35

2,412 Congenital 11

(d)

Weight at time of shunt Duration of shunt(d)

(g)

Complication Side of shunt Outcome Abbreviations:

SVC, SVC occlusion;

2

3

4

5

6

7

40

40

30

25

27

36

3,526 CDHISVC 46

1,925 Congenital 46

688 svc 66

855 cvs 53

4,300 Congenital IO

4,850 Died before removal

1,550 Died before removal

1,420 43

1,000 24

4,300 45

Right Died

Left Died

Left Resolved

Right Resolved

3,912 Congenital 23

2,480 79

3,990 30

Left Resolved

Occluded Left Removed

CVS, cardiovascular

Infection

surgery;

CDH/SVC,

CDH repair

Left Resolved

and SVC occlusion.

PLEUROPERITONEAL

SHUNTS

FOR PERSISTENT

CHYLOTHORAX

changes in plasma oncotic pressure, the treatment of a chylous effusion requires more aggressive management. The initial treatment for chylothorax usually involves the initiation of total parenteral nutrition and either repeated thoracenteses or chest tube placement. In most cases, these simple measures are successful; however, there are a number of infants with chylothorax in whom these techniques fail to resolve the situation. Malnutrition and metabolic instability secondary to the loss of chyle (rich in protein, lipids, and lymphocytes) begin to have an adverse effect on the patient.3 Although opinions vary, some investigators recommend an extended period of conservative management before initiating surgical treatment. This can be accompanied by severe nutritional and immunologic disturbances. Selle et al4 have suggested that surgical intervention is indicated when the daily loss of chyle exceeds 100 mL per year of age in children for a 5day period, fails to diminish over 14 days, or when nutritional complications appear imminent.5 Several different surgical procedures have been used in cases in which expectant therapy has been unsuccessful (drainage > 1 to 3 weeks). These include thoracotomy and thoracic duct ligation6s7 apical pleurectomy,* pleural abrasion or chemical pleurodesisg and videoassisted thoracoscopy procedureslo Thoracotomy with thoracic duct ligation remains a major procedure in an already compromised neonate. Apical pleurectomy or pleurodesis increases the possibility of pulmonary lymphedema, fibrosis, and further pulmonary demise. Videoassisted procedures are becoming more popular; however, the infant’s size and pulmonary status may limit its use. Because of the limited treatment options, Weese and Schoutenll in 1982 described the successful use of a pleuroperitoneal shunt in two adult patients in the treatment of a malignant pleural effusion. In 1983, Azizkhan et all2 used this method to treat five ventilator-dependent children with chylous effusions. The ideal shunt should have a pumping chamber that is capable of handling fluid with an increased viscosity. It must contain a one-way valve system that opens at a very low pressure. An additional feature is a reservoir that allows percutaneous irrigation. Because of the size of our patient population, we have placed the reservoirs in an external position to

289

minimize the discomfort associated with frequent pumping and interruption of the sleep cycle. With this method, we have not encountered reluctance or inability of the parents of the patients to pump the chamber on a regular basis in the two children discharged home with externalized shunts. The peritoneal cavity with its large absorptive surface has handled the lymph in all cases without difficulty. The only current contraindication noted for possible failure of a pleuroperitoneal shunt is increased right atria1 pressures greater than 25 mm Hg.13 Postoperative assessment of pleuroperitoneal shunt function can be accomplished in several ways. In most infants, simple noninvasive transcutaneous oxygen saturation monitors will demonstrate a decreased oxygenation if the effusion reaccumulates faster than the clearance rate of the pumping mechanism. An arterial blood gas determination documenting hypoxemia may support the findings of noninvasive monitoring. Chest radiographs are quite helpful in identifying recurrent effusions. Although chest ultrasonography has been shown to be very sensitive, and nuclear radionuclide scans have illustrated passive and active flow of chyle, these studies usually are not necessary. Our experiences with refractory chylothorax in the neonate indicate that the use of a pleuroperitoneal shunt is a safe and effective procedure. The procedure is easy to perform and associated with few complications. Metabolic, nutritional, and pulmonary stability can be restored effectively with this method. Postoperative catheter management is easily taught to nursing staff and family members allowing earlier discharge from the hospital. None of the patients required repositioning of the catheter as noted in a previous series (25%).14 We believe a pleuroperitoneal shunt is preferable to thoracic duct ligation, pleurectomy, pleurodesis, video-assisted thoracoscopy, and prolonged use of tube thoracostomy. Prompt identification of the high-risk infants (those with elevated central venous pressures and SVC thrombosis) and early intervention (7 to 10 days) in chylous effusions that fail to respond to more conservative management may minimize morbidity and possibly lead to shorter hospital stays.

REFERENCES 1. Bessone

LN, Ferguson

TB, Burford

TH: Chylothorax.

Ann Thorac

Surg 12:527-550, 1971 2. Sasson CS, Light RW Chylothorax and pseudochylothorax. Clin Chest Med 6:163-171, 1985 3. McWilliams B, Fan L, Murphy S: Transient T-cell depression in postoperative chylothorax. J Pediatr 99:595-597, 1981 4. Selle JG, Snyder WH III, Schreiber JT: Chylothorax: Indications for surgery. Ann Surg 177:245-249,1973 5. Milsom JW, Kron IL, Rheuban KS, et al: Chylothorax: An

assessment of current surgical management. J Thorac Cardiovasc Surg 89:221-227, 1985 6. 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 7. Patterson GA, Todd TRJ, Delarue NC, et al: Supradiaphragmatic ligation of the thoracic duct in intractable chylous fistula. Ann Thorac Sug 32:44-49,198l 8. Barrett DS, Large SR, Rees GM: Pleurectomy for chylothorax associated with intestinal lymphangiectasia. Thorax 42:557-558, 1987

ENGUM

9. Adler RH. Levinsky L: Persistent chylothorax: Treatment by talc pleurodesis. .I Thorac Cardiovasc Surg 76:859-864, 1978 10. Graham DD, McGahren ED, Tribble CG, et al: Use of videoassisted thoracic surgery in the treatment of chylothorax. Ann Thorac Surg57:1507-1512, 1994 11. Weese JC, Schouten JT: Pleural peritoneal shunts for the treatment of malignant pleural effitsions. Surg Gynecol Obstet 154:391-392,1982 12. Azizkhan RG, Canfield J, Alford BA, et al: Pleuroperitoneal

ET AL

shunts in the management of neonatal chylothorax. J Pediatr Surg 18842-850, 1983 13. Rheuban KS, Kron IL, Carpenter MA, et al: Pleuroperitoneal shunts for refractory chylothorax after operation for congenital heart disease. Ann Thorac Surg 53:85-87, 1992 14. Murphy MC, Newman BM, Rodgers BM: Pleuroperitoneal shunts in the management of persistent chylothorax. Ann Thorac Surg 48:195-200, 1989