Surgical exposure of the femoral vessels is a commonly required procedure in patients with peripheral arterial occlusive disease, deep vein thrombosis, or varicose veins. Care must be taken not to injure lymphatic tissues, as this may result in cumbersome complications such as lymphatic fistulae, cysts, and, eventually, infections. To avoid such complications, lymphatic physiology and anatomy must be considered during dissection. Management of established fistulae, in turn, depends on reliable localization and closure of the lymphatic leakage.
Lymph fluid is a protein rich, leukocyte containing fluid, which appears yellowish (amber) and is crystal clear (if not infected). It is transported actively in 8–12 subcutaneous channels from the foot to the groin, where some 16–20 lymphatic ducts converge and flow either into the first lymph node filter station or cross over directly into the pelvis. Flow is supported by vessel valves that are connected to lymphatic “hearts” pumping the fluid proximally by a beating automatism. The lymph system belongs to the reticuloendothelial system, which cleans the fluid from cellular fragments, proteins, and bacteria. Therefore, lymph nodes may enlarge reactively, even in the absence of a generalized lymph node disease, particularly in chronic critical limb ischemia.
Usually, the incision should be placed laterally from the arterial system and follow a longitudinal oblique direction. To establish access to the target vessel, a subcutaneous flap is lifted directly from the fascia without destroying or cutting lymph nodes or lymphatic vessels. This approach is an art, and has to be done slowly and carefully. The great “masters” often leave this crucial step to their assistants. This is only acceptable if they teach them first how to do it meticulously. Otherwise, they should not wonder why the patient develops a lymphatic fistula despite their “masterpiece” surgery! Importantly, the skin incision must not be too short, because constant retraction not only causes skin ischemia and necrosis, but also destroys lymphatic ducts. Therefore (in this particular context), big incision = great surgeon! If a lymph node is cut unintentionally, its capsule should be sewn over using fine sutures or it should be ligated altogether, depending on the amount of injury. If one or more lymphatic vessels have been cut through, immediate closure by ligation or clipping is necessary as, later on, leakages will be very difficult to localize.
Redo groin surgery is particularly challenging, as it is associated with an increased incidence of lymphatic fistula and infection, the combination of which can be catastrophic. The most dangerous period is between 2 weeks and 3 months after the original exposure and should be avoided if at all possible. Then, the healing process is most susceptible to disturbance and anatomic structures are particularly difficult to identify. In addition, fresh wounds usually show edema, which may necessitate even more tension from the retractor: so care must be taken! Additional established measures to avoid complications include a careful isolation of the wound edges using folded towels that are sutured tightly to the margin of the skin after thorough disinfection of the cleaned groin (e.g., betadine).
If a lymphatic cyst has developed despite the abovementioned measures, management may follow certain steps. If conservative management does not seem promising, a simple puncture may serve as a diagnostic procedure but from experience will rarely lead to definitive resolution. The injection of 5–10 mL tetracycline or other sealants into the emptied cavity may be helpful, as it causes a sterile inflammation that may eventually cause obliteration of the cyst. This is an accepted method, for instance, in children with lymph hemangioma, and also in kidney transplant patients, where lymphatic cysts occur in about 10–20% of cases.
In other cases, surgical revision becomes necessary eventually. Although the lymphatic flow usually appears in the distal edge of the wound, it is often difficult to localize the source exactly. It has been helpful to inject patent-blue subcutaneously into the floating skin fold between the first and second toe in such cases. Its small color particles are picked up by the lymphatic capillaries and are then transported to the groin within 30 to 45 min, where they facilitate identification of the injured lymphatic vessel for ligation. The dye should therefore be injected before initiation of anesthesia. As a side effect, however, patients may develop a swollen leg for 6 weeks–3 months. Another potential approach involves wound conditioning by application of negative pressure wound therapy for a few days.
In summary, lymphatic wound complications are a preventable cause of delayed groin wound healing and may even threaten the vascular reconstruction beneath. Therefore, the surgical vascular exposure must follow defined steps and particular attention should be paid not to injure lymphatic structures. In experienced hands lymphatic complications are a very rare problem, even after redo surgery. Thus, the correct approach must be taught and trained. At any rate, it must not be considered a minor procedure, because its failure may jeopardize the whole vascular reconstruction, particularly if prosthetic material is involved. Shortcuts to the abovementioned principles hardly ever save time. In contrast, they are risky and may entail an unnecessary waste of resources.
Published online: June 30, 2016
© 2016 European Society for Vascular Surgery. Published by Elsevier Ltd.