Chylous Ascites After Nephrectomy for Trauma

Chylous ascites has many etiologies including malignancy, infection, and inflammation. Management of this condition varies from conservative treatment to surgery. We present a case of chylous ascites after laparotomy for trauma and review the pathophysiology, etiology, diagnosis, and treatment options for this condition.

Case Report

An automobile traveling at moderate speed struck a 39-year-old male. He was initially treated at a referral institution and diagnosed with a flail chest. The referring doctor inserted bilateral tube thoracostomies, placed the patient on positive pressure ventilation, and transferred him to our level I trauma center. A computerized tomography (CT) scan confirmed bilateral pneumothoraces and demonstrated a grade V right renal laceration with a large, zone II retroperitoneal hematoma (Fig. 1). The patient became hemodynamically unstable with an expanding hematoma and underwent a right nephrectomy. His postoperative course was complicated by multiple organ failure from which he eventually recovered, and he was discharged to a rehabilitation facility 2 months after admission.

The patient returned several weeks later with complaints of nausea and vomiting. Physical examination was remarkable for tachypnea, tachycardia, and a distended, tight abdomen. CT revealed a large volume of ascites with a fatfluid level (Fig. 2). The ascites was compressing the patient’s stomach and duodenum and was likely the source of the patient’s abdominal complaints. A CT- guided paracentesis was performed with removal of 4 L of creamy liquid. A drain placed in the fluid collection yielded an additional 2 L of fluid overnight. Analysis of the fluid revealed a triglyceride level of 789 mg/dL. The patient’s tachypnea, tachycardia, and abdominal complaints all resolved with the fluid drainage. We placed the patient on a low-triglyceride diet, and he had cessation of the chyle leak within 1 week.

Discussion

Chylous ascites is an uncommon condition characterized by accumulation of lymphatic fluid in the peritoneal space. Depending on the series reported, the incidence of chylous ascites has ranged from 1 per 187,000 to 1 per 11,589.1 The physiologic effect of constant protein and lymphocyte loss into the peritoneum and the frequent association of this condition with underlying cancer result in a high morbidity and mortality.1

FIG. 1. The patient’s initial CT scan demonstrating the grade V renal injury and large, retroperitoneal hematoma.

FIG. 2. CT scan demonstrating a fat-fluid level. The ascites is causing marked compression of the patient’s stomach and duodenum.

Chylous ascites has two general etiologies: leakage of chyle from large abdominal lymphatics after trauma or surgery or from transudation caused by increased lymphatic pressure secondary to a proximal obstructive process.1, 2 The causes of chylous ascites are summarized in Table 1. In adults, the majority of cases of chylous ascites are secondary to lymphoma, and congenital causes are the most common etiology in children.1, 2 Postoperative chylous ascites is more likely to occur in procedures that include retroperitoneal dissection.1-3 Some authors feel that chylous ascites forming in the immediate postoperative period results from direct damage to large abdominal lymphatics, whereas the delayed appearance of the condition is from obstruction secondary to scarring.1 Blunt trauma can cause chylous ascites even if a laparotomy is not performed.1

TABLE 1. Causes of Chylous Ascites

In the patient described, a CT scan was pathognomonic for chylous ascites, but this is a rare finding.2 A paracentesis draining milky fluid with triglyceride levels greater than 100 mg/dL is consistent with chylous ascites.1-3 In other reports, radionucleotide scanning and lymphangiography have been used to localize lymphatic leaks.1, 3 On occasion, a laparotomy or laparoscopy may have both diagnostic and therapeutic value.

Conservative therapy begins with a diet that is high in carbohydrate and protein calories and low in fat. Fat should be administered as medium-chain triglycerides, as these are cleared by the portal rather than the lymphatic circulation. This may be accomplished by elimination of oral intake entirely while the patient is maintained on parenteral nutrition or, less expensively, through a fat-free diet. 1-3 Other therapeutic approaches have included the administration of diuretics1, 2 or octreotide.2, 4

Patients who fail conservative therapy for chylous ascites developing after trauma or surgery are candidates for surgical exploration.1, 2 The patient should receive a fat-rich feeding containing a lipophilic dye prior to surgery in order to aid visualization of the leaking lymphatic.1, 3 A leaking lymphatic identified at laparotomy should be ligated with nonabsorbable suture. If a leak is not identified, a peritoneovenous shunt should be placed.1, 3

REFERENCES

1. Aalami OO, Allen DB, Organ CH Jr. Chylous ascites: a collective review. Surgery 2000;128:761-8.

2. Leibovitch I, Mor Y, Golomb J, Ramon J. The diagnosis and management of postoperative chylous ascites. J Urol 2002;167:449- 57.

3. Wall JCH. Persistent chylous ascites after nephrectomy for renal cell carcinoma. Contemp Surg 2003;59:281-4.

4. Bhatia C, Pratap U, Slavik Z. Octreotide therapy: a new horizon in treatment of iatrogenic chyloperitoneum. Arch Dis Child 2001;85:234-5.

COLIN G. KNIGHT, M.D., LAUREL OMERT, M.D.

From the Shock Trauma Center, Allegheny General Hospital, Pittsburgh, Pennsylvania

Presented at the Annual Scientific Meeting and Postgraduate Course Program, Southeastern Surgical Congress, Atlanta, GA January 31-February 3, 2004.

Address correspondence and reprint requests to Colin G. Knight, M.D., 205 Montclair Ave., Pittsburgh, PA 15237.

Copyright The Southeastern Surgical Congress Dec 2004