Perilymph Fistula 

Vascular reconstruction inevitably results in lymphatic injury because the lymphatics are intricately associated with the arteries and veins and significant lymph node groups are found near major vessels. The lymphatic system, however, has a remarkable ability to regenerate and reestablish continuity after transection or ligation. Thus, most injuries to the lymphatic system are trivial and rarely contribute to surgical morbidity.

A small proportion of lymphatic injuries can result in significant morbidity, requiring further medical or surgical management. An injury to the infrainguinal lymphatic vessels during vascular reconstruction may result in lymphatic fistula or lymphocele. Chylous ascites might develop after injury to the paraaortic or mesenteric lymphatics during abdominal aortic reconstruction. Thoracic duct injuries during thoracoabdominal aortic reconstruction may result in chylothorax. This myriad of lymphatic injuries during vascular reconstruction constitutes a rare but complex situation for both the patient and the surgeon.

• Lymphatic fistula after infrainguinal reconstruction: The advent of infrainguinal reconstruction for lower limb salvage introduced this complication. In 1991, Kalman et al described the most comprehensive series of patients with postoperative lymphatic fistulae after infrainguinal reconstruction.^[1] Other case reports and smaller collected series were described prior to this comprehensive review.
• Chylous ascites: Several case reports and much smaller clinical series (beginning in 1970) describe the development of chylous ascites after abdominal aortic reconstruction.
• Chylothorax: A few case reports describing chylothorax following thoracoabdominal aortic reconstruction were submitted beginning in 1979. A more extensive review began in 1996 with the advent of congenital aortic coarctation repair.

• Lymphatic fistula is an epithelialized tract that develops between the lymphatic system and the epidermis after lymphatic injury during infrainguinal reconstruction.
• Chylous ascites is an effusion of chyle into the intra-abdominal cavity after lymphatic injury to the paraaortic or mesenteric lymphatics (eg, the cisterna chyli).
• Chylothorax is an effusion of chyle into the pleural cavity, usually after a thoracic duct injury.

Frequency

• Lymphatic fistula: In the most comprehensive review of lymphatic fistulae after infrainguinal reconstruction, Kalman et al reported an incidence of 1.1%.^[1] Smaller series report an incidence of 0.8-6.4% after reconstructive procedures.
• Chylous ascites: A review of the world literature from 1969-2001 reveals approximately 25 case reports of chylous ascites developing after abdominal aortic reconstruction.
• Chylothorax: Chylothorax after cardiothoracic surgery has an incidence of 0.2-1%. Scattered case reports describe chylothorax after thoracoabdominal and abdominal aortic reconstruction.

• Lymphatic fistula: Etiologic factors contributing to lymphatic fistulae after infrainguinal reconstruction include failure to ligate injured lymphatic vessels and failure to meticulously approximate tissue layers at closure. Other risk factors for the development of lymphatic fistulae include diabetes mellitus, wound infections, reoperation, use of prosthetic grafts for vascular conduits, and excessive postoperative ambulation.
• Chylous ascites: Failure to meticulously dissect around the abdominal aorta and failure to ligate the larger lumbar, paraaortic, and mesenteric lymphatic vessels may result in postoperative chylous ascites. Other causes of chylous ascites include neoplasms (eg, lymphoma), cirrhosis, trauma, congenital lymphatic abnormalities, infections (eg, peritoneal tuberculosis), and inflammatory disorders.
• Chylothorax: Inadvertent transection of the thoracic duct results in this complication. Like chylous ascites, many nontraumatic etiologies exist for chylothorax, including malignancy, congenital disorders, and various infectious and inflammatory processes.

• Lymphatic fistula: Transection of the infrainguinal lymphatic vessels results in lymphatic leakage. Collection of lymphatic fluid in the groin may result in wound infection, prosthetic graft infection, and lymphocele, which may have a negative effect on progressive postoperative rehabilitation.
• Chylous ascites: Lymphatic leakage from the paraaortic or mesenteric lymphatic vessels into a closed compartment, such as the intra-abdominal cavity, has much greater implications for postoperative morbidity. When lymphatic leakage outstrips reabsorption, progressive abdominal distention occurs and can subsequently lead to pulmonary compromise. Malnourishment and infectious complications may result from the loss of proteins, fats, and vital immunologic complexes.
• Chylothorax: Lymphatic leakage from the thoracic duct into a closed compartment, such as the thoracic cavity, inevitably results in respiratory difficulty. Malnourishment and infectious complications may also result from such a substantial lymphatic leak.

• Lymphatic fistula: The diagnosis may be established by the leakage of clear yellow fluid from an infrainguinal incision that occurs days to months after infrainguinal vascular reconstruction. A lymphocele may be diagnosed by the presence of lymphatic drainage in a soft, fluid-filled cyst.
• Chylous ascites: Patients usually develop progressive abdominal distention and pain accompanied by nausea and vomiting several days to weeks following abdominal aortic reconstruction. The presence of a fluid wave indicating ascites may be appreciated on abdominal examination. Lymphopenia and anemia may also develop.
• Chylothorax: The presence of decreased breath sounds at the lung bases and dullness to percussion may suggest the presence of an effusion and chylothorax. Pulmonary compromise ensues several days after thoracoabdominal aortic reconstruction or repair of aortic coarctation. Hematologic depression, such as lymphopenia and anemia, may also develop.

• Lymphatic fistula: Indications for operative repair of lymphatic fistulae include a failure to respond to conservative management, a persistently draining high-volume fistula, and an enlarging or symptomatic lymphocele. Conservative treatment includes bed rest with leg elevation, local wound care, and administration of intravenous antibiotics.
• Chylous ascites: Exploratory laparotomy for chylous ascites after previous abdominal aortic reconstruction is indicated if the patient does not improve with complete bowel rest, total parenteral nutrition (TPN), and repeated paracentesis.^[2]
• Chylothorax: Thoracotomy for chylothorax after prior thoracoabdominal or abdominal aortic reconstruction is indicated if the patient does not improve with conservative therapy consisting of closed drainage via a thoracostomy tube and TPN.

• Lymphatic fistula: The demonstration of isosulfan blue (Lymphazurin dye) leakage within the reexplored infrainguinal incision aids in the repair of lymphatic fistulae. Blue droplets appear from the site of lymphatic injury, which may then be suture ligated, cauterized, or fibrin glued.
• Chylous ascites: Several large mesenteric lymphatics are located on the anteroinferior aspect of the left renal vein. These mesenteric lymphatics, along with the right and left lumbar lymphatics, form the cisterna chyli. The cisterna chyli lies between the inferior vena cava and the abdominal aorta at the level of the second lumbar vertebra.
• Chylothorax: The thoracic duct lies to the right of the aorta and to the left of the azygos vein. It begins at the cisterna chyli and enters the posterior mediastinum through the aortic hiatus. In the superior mediastinum, the thoracic duct lies behind the aortic arch and subclavian artery, to the left of the esophagus, and enters the left brachiocephalic vein.

The only contraindication to operative repair of lymphatic fistulae, chylous ascites, and chylothorax includes standard preoperative comorbidities that require continuance of conservative therapy (eg, recent myocardial infarction). As with any surgical therapy, the risk-benefit ratio must be assessed.