TY - JOUR
AU - USA, Daniel J. Gallagher, MC
AB - ABSTRACT Chyle leaks are a rare but potentially fatal complication of head and neck surgery carrying an incidence as high as 8.3%. The development of a chyle leak carries significant morbidity ranging from delayed wound healing to oropharyngeal fistulas. Presented here is a case of a chyle leak that developed following a left posterolateral neck dissection that was successfully managed with a combination of drain suction, pressure dressing, and a fat-restricted diet. However, the patient's course was complicated by repeated chyle leak recurrences that may have been associated with the initiation of medium-chain triglyceride supplementation. Although further research is required to establish a causal relationship, these findings support the concerns of other investigators about the possible counterproductive role of medium-chain triglyceride supplementation in the management of chyle leaks. INTRODUCTION The earliest reports of chyle leaks following neck surgery were by Cheever in 1875 and Allen and Briggs in 1901.1 Since that time, chyle leaks have remained a rare but potentially fatal complication of head and neck surgery. Although the incidence of chyle leaks is generally reported as less than 1 to 2.5%,2 the incidence specific to left neck dissections has been found to be as high as 8.3%.3 The development of a chyle leak carries significant morbidity. A leak that is left untreated may lead to delayed wound healing, impaired nutrition, compromise of skin flaps, or the formation of orocutaneous or pharyngocutaneous fistula.3 The combined reported mortality rate for untreated chyle leaks has been seen as high as 50%, though this rate is largely influenced by larger chyle leaks in the thorax and abdomen.4 Understanding the causes of this complication and the management choices available for its correction are important for any surgeon intending to operate in the neck. Presented here is a case of a chyle leak that developed following a left posterolateral neck dissection that was successfully managed with conservative measures. CASE REPORT The patient is a 49-year-old Caucasian male who was in his normal state of good health when he identified a firm, painless mass in his left neck. After a nondiagnostic fine needle aspiration, he underwent open biopsy of a level IIb left neck node, confirming metastatic melanoma. The primary lesion was determined to be on the vertex area of the scalp, just to the left of the midline. The patient subsequently underwent a left posterolateral neck dissection to include suboccipital nodes and levels II, III, IV, and V. In the course of the dissection in level IV, a small chyle leak was noted from the thoracic duct, which resolved with the placement of medium hemoclips. Before closing, the wound bed was thoroughly irrigated with saline, tested with 40 mm Hg of Valsalva pressure, and sealed with TISSEEL fibrin sealant (Baxter Healthcare Corporation, Montgomery, New York) over the clipped thoracic duct and level IV. No further leak or bleeding was appreciated and the wound was closed in layers in the standard fashion, placing two Jackson–Pratt (JP) drains inferiorly in level IV. The patient recovered well in the immediate postoperative period and was transferred to the floor for observation. The JP drains were maintained on continuous bulb suction. On postoperative day 1 (POD1), the patient reported only mild neck pain and his drainage was 110 mL of serosanguinous fluid. He was started on a regular diet and encouraged to ambulate (Fig. 1). On POD2, his drain output was more than doubled (250 mL) and turned from serosanguinous to a thin, white, milky fluid concerning for chyle. The wound and skin flap remained healthy and flat, without any apparent fluid collection. A multi-faceted approach was utilized to address the apparent leak. A pressure dressing was applied to the wound, suction was transferred from bulbs to low intermittent wall suction, bed rest was ordered and a low-fat diet was initiated. On POD3, the drainage had returned to serosanguinous, although the volume remained high (344 mL). FIGURE 1. View largeDownload slide Demonstrating the relationship between management decisions and wound drain output. FIGURE 1. View largeDownload slide Demonstrating the relationship between management decisions and wound drain output. In consultation with the inpatient dietary team, medium-chain triglyceride (MCT) oral supplementation was added to the patient's diet. This was provided through 1.5 kcal shakes, which provided 40.5 g of MCT daily, accounting for 100% of the patient's dietary fat need. On POD4, there was a decrease in drain output (228 mL), but the fluid had again become milky. Because of the concern that the force of low intermittent wall suction may have disrupted the healing thoracic duct, the patient was placed back on bulb suction. However, the chylous discharge persisted. The pressure dressing was noted to be causing significant irritation to the patient's throat and causing him to cough. Therefore, the pressure dressing was removed on POD4 and then reapplied the following day with the elastic bandage secured around the contralateral axilla, thereby minimizing the patient's discomfort. Additionally, the anterior drain (JP1) had become clotted and was therefore removed. On POD6, the chylous discharge continued and had increased slightly (130 mL) from the previous day (114 mL). The patient was made NPO (nothing by mouth), was restricted to bed rest, and the pressure dressing was left in place. The following day, the discharge had reduced by over 50% and become serous. On POD7, the patient was kept NPO, was allowed out of bed to a chair and octreotide 50-mcg subcutaneous injections every 8 hours was ordered for the following morning. The drainage remained serous and on POD8, the patient was slowly transitioned to a no-fat, clear-liquid diet and then no-fat solids were incorporated on POD9. Octreotide was continued for 48 hours in order to minimize the absorption of dietary fats as food was reintroduced. The drainage remained low (73 mL, 75 mL) and serous. The patient was discharged on the following day, POD10, on a no-fat diet and instructed to follow up in 1 week. At follow-up, the patient's wound was healing well with no signs of a renewed chyle leak or fluid collection. The drain was removed and he was successfully transitioned to a regular diet over the ensuing weeks without further complication. DISCUSSION The increased incidence of chyle leaks during left neck dissection is due to the increased likelihood of damage to the thoracic duct, which terminates on the left in 75 to 92% of patients.5,6 The duct arises from the cisterna chyli near the second lumbar vertebra, passes between the aorta and azygous vein to enter the neck, and then travels left behind the great vessels to lie on the anterior scalene and phrenic nerve. The duct will then terminate in the left internal jugular vein (IJV) in most cases. However, it may also terminate in the left subclavian, left external jugular vein, left innominate vein, or right IJV. Additionally, the thoracic duct will terminate in more than one branch in up to 50% of cases.7 This anatomical path brings the thoracic duct in close contact with several key structures that are routinely manipulated or dissected in the performance of a left neck dissection. Accordingly, damage to the thoracic duct can occur when removing lymph nodes from level IV, while preserving the phrenic or vagus nerves or during dissection of the IJV.2 Chyle, derived from the Latin word for juice, is a combination of lymph and emulsified fat carried from the intestines and returned to general circulation via the thoracic duct.8 The amount of chyle produced by the body ranges from 1 mL/min while fasting to 200 mL/min following a high-fat meal for an overall value of 2 to 4 L/d.1,9 The value also varies in response to certain medical conditions, such as malignancy or cirrhosis, where it has been found to increase to as much as 8 L/d.9 The fluid is composed of 2 to 4.5% protein and 1 to 3% fat, primarily long-chain triglycerides. These insoluble long-chain triglycerides comprise approximately 95% of dietary fat and require emulsification by bile salts. In contrast, MCTs are water soluble, and are absorbed directly into the portal system as albumin-linked fatty acids and therefore bypass the lymphatic circulation.9 It is because of this difference in absorption that MCTs are typically considered safe in the management of chyle leaks, as they should not contribute to the volume of chyle produced. The best management of a chyle leak is prevention. However, this is frequently complicated by the highly variable anatomy described above and the need to remove lymphatic and fibrofatty tissue from the region of the thoracic duct during neck dissection. Malignancy, previous surgery, or radiation therapy can have a significant impact on the surgeon's ability to clearly identify the anatomy required to preserve the thoracic duct.7 Moreover, a patient's NPO status before surgery naturally decreases flow in the system and makes an intraoperative leak harder to identify. When a leak is noted intraoperatively, the duct may be closed with suture ligature, metal clips, or extended application of pressure (Fig. 2).2 If more aggressive repair is required, fibrin glue, oversewing of the rotated omohyoid or sternoclidomastoid muscles, or pedicled flaps such as pectoralis major may be required.8 Intraoperative identification can be further aided through the use of the Trendelenburg maneuver and the application of Valsava pressure.8 FIGURE 2. View largeDownload slide A decision tree for the management of operative chyle leaks.2,10; TPN: total parenteral nutrition; MCT: medium chain triglycerides. FIGURE 2. View largeDownload slide A decision tree for the management of operative chyle leaks.2,10; TPN: total parenteral nutrition; MCT: medium chain triglycerides. Postoperatively, the first step in management is early and accurate identification of the leak. Diagnosis of chyle leak is frequently delayed as a result of the insidious onset and variable presentation. Although 86% of leaks present with swelling at the surgical site within 72 hours of surgery, leaks have been reported up to 3 months later.5 A high index of suspicion and clinical analysis of discharge from the wound are necessary. Chyle fluid is defined as a thin, milky fluid with triglyceride (TG) content >100 mg/dL higher than serum TG.3 Pakula et al showed that a TG > 110 mg/dL confirms the diagnosis of chyle leak and TG < 50 mg/dL is enough to exclude the diagnosis. With intermediate values of 50 to 100 mg/dL, follow up with lipoprotein analysis can help to identify the fluid. The presence of chylomicrons and the absence of cholesterol crystals can also be used to confirm the diagnosis.10 Conservative management is successful in 58 to 100% of chyle leaks.5 The 2 tenets of conservative management are to minimize further trauma to the source of the leak and to minimize chyle production. The first of these can be accomplished through the use of compressive dressings, bulb suction, and bed rest.2 The second is primarily a diet-based strategy to minimize fat ingestion. If these measures fail to stop the leak, 24 to 48 hours of NPO can be started with or without the addition of octreotide. Octreotide is a long-acting analog of somatostatin, which reduces the gastrointestinal production of chyle by reducing splanchnic blood flow and decreasing gastric, biliary, pancreatic, and intestinal secretions.5,11 In our patient, there appeared to be a connection between the institution of MCT oral supplementation and the recurrence of chylous discharge. As seen in Figure 1, a milky discharge developed on the day following implementation of a regular diet, and resolved 24 hours after transitioning to a no-fat diet. When the MCTs were added on POD3 for nutritional supplementation, the chylous discharge returned and continued despite other changes in management, eventually resolving only after the patient was made NPO. Although by the nature of a case report, there is inadequate data to establish a causal relationship, these findings support the concerns of other investigators concerning the role of MCT supplementation in the management of chyle leaks.8,10 It has been argued that MCTs do not completely avoid the lymphatic circulation and only partially replace the essential nutrients needed in a healing patient.8 Therefore, MCTs do not adequately assuage the nutritional concerns of a fat-restricted diet and may contribute to chyle volume. Based on these conclusions, they recommend that if a diet must be reinitiated for nutritional concerns, total parenteral nutrition (TPN) is a better, more effective diet strategy.8 For our patient, we saw significant resolution of the chyle leak within a 48-hour NPO period and therefore did not require TPN. A conservative approach, as described above, will not likely be adequate for drainage that is either persistent (>600 mL/d for 5–7 days), high flow (>1.5–2.0 L/d), or when there are signs of developing complications.8 In these cases, surgical intervention should be considered.8 Such intervention may include percutaneous lymphangiography-guided cannulation with embolization of the thoracic duct, injection of sclerosing agents such as tetracycline or povidone-iodine, or surgery. Endoscopic surgery and robotic approaches are also options for minimally invasive surgical management of chyle leaks.7,8 Minimally invasive techniques are shown to carry less morbidity and are associated with shorter hospital stays. When available, these should be considered before open revision surgery. These techniques are, of course, limited by the need for specialized training and equipment.2,12 CONCLUSION A postoperative chyle leak can be a challenging complication of neck surgery. Although the best course is prevention, conservative management is a highly effective strategy in many cases. The combination of drain suction, pressure dressing, and a fat-restricted diet should be considered the first-line therapy. This case report emphasizes the need for further investigation into the role of MCT supplementation. The benefit of additional enteral calories and lipids in the patient's diet must be balanced with the possibility that a portion of these fats are contributing to the chyle leak volume. REFERENCES 1. Scorza LB, Goldstein BJ, Mahraj RP Modern management of chylous leak following head and neck surgery: a discussion of percutaneous lymphangiography-guided cannulation and embolization of the thoracic duct. Otolaryngol Clin North Am  2008; 41( 6): 1231– 40, xi. Google Scholar CrossRef Search ADS PubMed  2. Gregor RT Management of chyle fistulization in association with neck dissection. Otolaryngol Head Neck Surg  2000; 122( 3): 434– 9. Google Scholar PubMed  3. Roh JL, Yoon YH, Park CI Chyle leakage in patients undergoing thyroidectomy plus central neck dissection for differentiated papillary thyroid carcinoma. Ann Surg Oncol  2008; 15( 9): 2576– 80. Google Scholar CrossRef Search ADS PubMed  4. Kumar S, Kumar A, Pawar DK Thoracoscopic management of thoracic duct injury: is there a place for conservatism? J Postgrad Med  2004; 50( 1): 57– 9. Google Scholar PubMed  5. Rammal A, Zawawi F, Varshney R, Hier MP, Payne RJ, Mlynarek AM Chyle leak: a rare complication post-hemithyroidectomy. Case report and review of literature. Otolaryngol Pol  2014; 68( 4): 204– 7. Google Scholar CrossRef Search ADS PubMed  6. de Gier HH, Balm AJ, Bruning PF, Gregor RT, Hilgers FJ Systematic approach to the treatment of chylous leakage after neck dissection. Head Neck  1996; 18( 4): 347– 51. Google Scholar CrossRef Search ADS PubMed  7. Kerawala CJ, Heliotos M Prevention of complications in neck dissection. Head Neck Oncol  2009; 1: 35. Google Scholar CrossRef Search ADS PubMed  8. Brennan PA, Blythe JN, Herd MK, Habib A, Anand R The contemporary management of chyle leak following cervical thoracic duct damage. Br J Oral Maxillofac Surg  2012; 50( 3): 197– 201. Google Scholar CrossRef Search ADS PubMed  9. Otero L, López F, Blanco O, Vázquez Á, Osorio P Diz I: [Neck chylous fistula: conservative treatment]. Nutr Hosp  2010; 25( 6): 1041– 4. Google Scholar PubMed  10. Pakula AM, Phillips W, Skinner RA A case of a traumatic chyle leak following an acute thoracic spine injury: successful resolution with strict dietary manipulation. World J Emerg Surg  2011; 6: 10. Google Scholar CrossRef Search ADS PubMed  11. Rodier JF, Volkmar PP, Bodin F, Frigo S, Ciftci S, Dahlet C Thoracic duct fistula after thyroid cancer surgery: towards a new treatment? Case Rep Oncol  2011; 4( 2): 255– 9. Google Scholar CrossRef Search ADS PubMed  12. Scott KJ, Simko E Thoracoscopic management of cervical thoracic duct injuries: an alternative approach. Otolaryngol Head Neck Surg  2003; 128( 5): 755– 7. Google Scholar CrossRef Search ADS PubMed  Footnotes 2 I am a military service member. This work was prepared as part of my official duties. Title 17 U.S.C. § 105 provides that “Copyright protection under this title is not available for any work of the United States Government.” Title 17 U.S.C. § 101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person's official duties. Reprint & Copyright © Association of Military Surgeons of the U.S.
TI - Conservative Management of an Intraoperative Chyle Leak: A Case Report and Literature Review
JF - Military Medicine
DO - 10.7205/MILMED-D-15-00240
DA - 2016-09-01
UR - https://www.deepdyve.com/lp/oxford-university-press/conservative-management-of-an-intraoperative-chyle-leak-a-case-report-eVdrn0aLII
SP - e1180
EP - e1184
VL - 181
IS - 9
DP - DeepDyve
ER -