A lymphocele is a common complication following pelvic surgery, particularly after a radical prostatectomy. It is defined as an encapsulated collection of lymphatic fluid that accumulates near the surgical site in the pelvis. These fluid collections often remain small, do not cause symptoms, and frequently resolve on their own without requiring active intervention.
How Lymphoceles Form After Surgery
The formation of a lymphocele results from disrupting the lymphatic network during surgery. The lymphatic system in the pelvis collects and returns tissue fluid, called lymph, back into the bloodstream via vessels and lymph nodes near the prostate.
During a radical prostatectomy, especially when a pelvic lymph node dissection (PLND) is performed, these lymphatic channels are cut or damaged. Although surgeons attempt to seal these vessels, some inevitably leak lymph fluid into the empty space created by tissue removal.
This constant leakage leads to fluid accumulation in the retroperitoneal space of the pelvis. Initially, this may be a simple fluid accumulation, but over time, the body attempts to contain it by forming a fibrous wall or capsule around the collection. This encapsulated collection of lymphatic fluid is then classified as a lymphocele. The rate of formation correlates highly with the extent of the lymphadenectomy, as removing more nodes severs more lymphatic vessels.
Symptoms and Patient Risk Factors
Most lymphoceles, up to 90% detected by routine imaging, remain entirely silent and are discovered incidentally during follow-up scans. Symptomatic lymphoceles typically present a few weeks after surgery, often around three weeks post-procedure.
Symptomatic collections cause problems by pressing on neighboring structures in the confined pelvic space. This pressure can result in discomfort or pain in the lower abdomen, groin, or back. If the lymphocele compresses major veins, it can impede blood return, leading to swelling (edema) in the lower extremities or genital area.
Compression of the bladder or ureters can cause urinary issues, such as increased frequency, difficulty voiding, or blockage of urine flow. If the lymphocele becomes infected, patients may develop systemic signs like fever or chills.
Several patient and procedural factors increase the likelihood of developing a symptomatic lymphocele. The most significant factor is the extent of the pelvic lymph node dissection, as removing a higher number of lymph nodes dramatically increases the risk.
Patient characteristics also play a role, with a high Body Mass Index being a consistent predictor of symptomatic collections. Other factors, such as the use of prophylactic low-molecular-weight heparin (which prevents blood clots) or having high-grade prostate cancer (Gleason score 8 or higher), have been associated with increased risk.
Diagnosis and Treatment Approaches
Confirmation of a lymphocele is achieved through medical imaging to determine its size, location, and relationship to nearby organs. Ultrasound is typically the initial, non-invasive method used to identify a fluid-filled mass.
For detailed assessment before intervention, a Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI) may be utilized. These scans provide anatomical detail, helping distinguish a lymphocele from other fluid collections like a hematoma or urinoma, and guide the management strategy.
For the majority of small, asymptomatic lymphoceles, the standard approach is non-invasive observation, often called “watchful waiting.” The body frequently reabsorbs the leaked fluid over several weeks or months, meaning no active treatment is needed.
Active intervention is necessary when the lymphocele is large, causes significant pain, compresses vital structures, or shows signs of infection. The first-line treatment for a symptomatic lymphocele is usually image-guided percutaneous drainage.
During this minimally invasive procedure, a radiologist uses imaging guidance to insert a drainage catheter into the fluid collection. The catheter remains in place for days or weeks to continuously drain the accumulated lymph. Sometimes, a sclerosing agent is instilled through the drain to encourage the walls to close, preventing recurrence.
If drainage fails or the lymphocele recurs repeatedly, laparoscopic marsupialization may be performed. This surgical procedure uses minimally invasive techniques to create an opening in the lymphocele wall. This allows the fluid to drain into the peritoneal cavity, where the body can absorb it more effectively.