Robotic prostatectomy leading to a delayed MRSA infected lymphocele: a case report and review of the literature

Abstract

Prostate cancer is the second leading cancer-related cause of death in the USA with the majority presenting as localized disease. In the last decade minimally invasive, robotic-assisted laparascopic, radical prostatectomy has become the most favored treatment choice. A complication that has been observed in 27% of patients is the formation of an asymptomatic lymphocele. It is a very rare complication for these to become infected, and when they do 80% have occurred 2–12 months post-procedure. In this case report the patient presented with fever and leukocytosis of unknown origin and was found to have a methicillin-resistant Staphylococcus aureus (MRSA) infected lymphocele over 2 years after a radical prostatectomy. The infected fluid collection was drained percutaneously and the patient was treated with a 4-week course of intravenous ceftaroline with complete resolution of symptoms.

Introduction

Prostate cancer is the second leading cancer-related cause of death in the USA, affecting 1 in 7 men in their lifetime.^1,2 In the last decade, minimally invasive, robotic-assisted laparoscopic radical prostatectomy (RALRP) has become a common treatment choice.^1–3 Eighty percent of radical prostatectomies are completed in this fashion, and a complication rate of 10.8% has been reported in the literature; with or without pelvic lymph node dissection (PLND).^1,2 A common risk associated with the procedure is postoperative lymphocele formation, at an incidence of 27%.^1,4 This collection contains lymphatic fluid without a distinct epithelial lining, and may occur when there is inadequate closure and injury of lymphatic vessels following surgical dissection.^3–5 Although lymphocele formation following PLND is relatively common, it is rare for a lymphocele to become symptomatic, and those that do are usually detected in the first 2–12 months.^5,6

Case report

A 62-year-old Caucasian male patient with past medical history of prostate cancer status post total resection by robotic surgery in 2013 with PLND, ulcerative colitis in remission on mesalamine with yearly negative colonoscopies, presented with dull, aching, non-radiating right lower quadrant pain, fever and chills for 6 days. He was initially taking Tylenol, ibuprofen and 3 days of levofloxacin at home to control his symptoms with only slight improvement. Blood work revealed an elevated white blood cell count of 20,000 (47,000–10,300 K/µl) and an increased erythrocyte sedimentation rate of 86 (0–20 mm/H) at which time he was admitted to the hospital for further intervention. An abdominal CT-scan with intravenous and oral contrast showed a 6.5 cm × 6.2 cm × 5.8 cm low attenuation structure in the right quadrant with prominent inflammatory changes (Figures 1 and 2). It also revealed inflammatory changes extending from the right lower quadrant to the right pelvis and enhancing wall. Interventional radiology (IR) drainage of the fluid collection was performed, a sample of the purulent fluid was sent for culture, and a pigtail catheter was placed for residual drainage. The patient was empirically started on antibiotic coverage with IV piperacillin-tazobactam until the culture came back positive for methicillin-resistant Staphylococcus aureus (MRSA) at which point IV vancomycin (minimum inhibitory concentration (MIC): 1.0) was added to the treatment regimen.

Figure 1.

Transverse CT-scan with IV contrast showing 6.5 × 6.2 × 5.8 cm low attenuation structure in the right quadrant with prominent inflammatory changes.

Figure 2.

Coronal view of the same CT-scan showing the 6.5 × 6.2 × 5.8 cm low attenuation structure in the right quadrant with prominent inflammatory changes.

Within a few days the patient was subjectively feeling better, the white blood cell count had trended down and a repeat abdominal CT-scan showed near complete resolution of the right lower pelvic fluid collection (Figure 3). The drain was removed from the patient.

Figure 3.

Transverse CT-scan with IV contrast showing resolution of the fluid collection.

Three days after drain removal an upward trend of white blood cells was noted, and a repeat abdominal CT-scan showed a re-accumulation of the right lower pelvic fluid to 3.8 × 2.8 × 2.9 cm in size. A second percutaneous drainage was performed yielding 10 cc of slightly purulent, serosanguineous fluid with a new pigtail catheter placed for continued drainage. The fluid was positive for triglycerides confirming the diagnosis of an infected lymphocele. Culture again confirmed the presence of MRSA with additional testing showing ceftaroline sensitivity at a MIC of 0.5.

On the ninth day of hospitalization the patient was deemed stable for discharge. Although the MIC of vancomycin was 1.0, due to the slight trend upward in leukocytes and the re-accumulation of fluid while on this antibiotic, it was determined that it would be beneficial to change the patient to another suitable sensitive antibiotic; he was started on ceftaroline 600 mg IV every 12 h for 4 weeks via PICC line. At follow up visit, 1 week post discharge, a pelvic ultrasound was conducted and confirmed that there was no evidence of focal fluid collection in the right lower quadrant. Four weeks of antibiotic coverage with ceftaroline were concluded with no reappearance of fever or leukocytosis.

Discussion

A lymphocele is a collection of lymphatic fluid without a clear epithelial border. ⁵ It occurs when the afferent lymphatic vessels are cut and inadequately closed during a pelvic lymphadenectomy.^5,7 Although surveillance imaging is not routinely conducted following a prostatectomy, a few studies have been conducted to assess the rate of lymphocele formation. ³ Orvieto and colleagues used CT surveillance 6–12 weeks after RALRP with limited PLND and found lymphocele formation in 51% of patients, with 15.4% symptomatic. ³

It is rare that pelvic lymphoceles become symptomatic, and of those that do, 80% are noticed in the first 2–12 months.^5,6 The initial presentation may include ileus, fever, abdominal pain, lower extremity edema, gastrointestinal complaints or lower urinary tract symptoms that occur due to the mass effect of the lymphocele on nearby organs. ⁵ Fever is the most common presenting complaint in 47% of patients, followed by abdominal pain in 40%. ⁵ On physical examination there may be a palpable, lower abdominal mass that is fluctuant in nature. ⁵ On ultrasound examination the lymphocele will show an anechoic cystic structure that may have septations and debris. ⁵ On CT-scan, the lymphocele will show a hypodense lesion with low attenuation that is thin-walled if uninfected, or has a thickened wall with regional enhancement if infected. ⁵ Our patient presented with fever at onset, which is consistent with the most common presentation of lymphocele. He was found to have a low attenuation focus with regional enhancement on CT-scan; the presentation of an infected lymphocele.

Carbone and colleagues discuss a patient with infected lymphocele that occurred more than 1 year post-operatively. ⁶ The patient presented initially with fever and chills of unknown etiology and was later found to have a pelvic lymphocele seeded with Streptococcus agalactiae. ⁶ It was suspected that the existing lymphocele became infected after the bacteria spread from a superficial leg wound. ⁶ This was compared to the one other reported case of an infected lymphocele occurring greater than 1 year post-procedure in which the patient also presented with fever and chills of unknown etiology.^6,8 As with these previously reported cases the initial presentation of our patient showed fever, chills and leukocytosis of unknown etiology but unlike these cases, our patient was over 2 years post-procedure at the time of presentation.

There is no intervention necessary if the pelvic lymphocele is asymptomatic and without mass effect on nearby organs.^6,9 Spontaneous regression usually occurs.^3,6,7 Some 3–14% of lymphoceles are found to be symptomatic with significant inflammatory, disabling complications that include: abdominal pain, leg pain, lower extremity edema, urinary frequency, infection or sepsis, and thromboembolic events from a compressed pelvic vessel.^2,3,6,10 Infected pelvic lymphoceles may resolve spontaneously, but often, if the patient has evidence of systemic infection, a percutaneous drain placement is performed with fluid being sent for bacterial culture and for creatinine level to exclude a urine leak.^3,5,6 Drain duration can vary from a few days to a few months. ⁵ If the drain continues to show a large volume of output it is sometimes necessary to inject sclerosing agents through the tube to seal the lymphatic channels. ³ These include: povidone-iodine, alcohol, talc, bleomycin, tetracycline or fibrin seals such as Tisseal ®.^3,5,11 The downfall to percutaneous drainage is that rapid re-accumulation of fluid is a very common finding and having repeated aspiration can lead to increased risk of infection.^6,9 If the lymphocele is large in size and external drainage is not possible or has failed to resolve the lymphocele, then it may be necessary to resect the cyst wall with surgical marsupialization of the lymphocele into the peritoneal cavity by either open or laparoscopic procedure.^3,5,6,9 The open surgical procedure has been found to have a 50–70% success rate, and the peritoneal marsupialization shows a 90% success rate. ¹¹ The downfall is that for these surgical procedures there is a need for general anesthesia and longer hospitalization. ¹¹ Whereas RALRP is a method now in use that has shown to be effective, has minimal patient morbidity and has rapid recovery time. ⁹ It is often reserved for the more complicated lymphoceles with multiple loculations and the open procedure is typically only for the severely infected and complicated lymphoceles that did not resolve by percutaneous draining or laparoscopic marsupializiation.^3,5

A percutaneous procedure with drain placement was performed for our patient, with a sample being sent for bacterial culture. Consistent with the literature, he experienced a re-accumulation of fluid; a common downfall to percutaneous drainage. ⁶ Upon repeated aspiration and longer duration of drain placement, the patient achieved complete resolution of the fluid collection. In conjunction to percutaneous drainage, it was necessary for the patient to take appropriate antibiotic therapy once the culture was found to be growing MRSA.

During the last decade the incidence of MRSA has rapidly increased and now accounts for more than half of all staphylococcal disease. ¹² The patient presented in this case report had no skin lesions or disruptions that could explain the entry of Staphylococcus aureus into the lymphatic system. His ulcerative colitis was in remission as was confirmed with yearly colonoscopy. He had no history of being infected with MRSA himself, but many members of his household had history of prior MRSA infections, which may have provided exposure of the patient to this bacterium.

The patient was originally treated with vancomycin, a commonly used antibiotic due to its effectiveness against MRSA. ¹³ Generally if the MIC is 2 mg/l or greater, an alternative therapy should be considered. ¹³ This is because increasing the vancomycin dosage to achieve a target area under the concentration-time curve (AUC): MIC ratio would increase the potential for toxicity. ¹³ This may include infusion-related reaction, ototoxicity or nephrotoxicity. ¹³ Although our patient had a favorable MIC of 1.0, he was noted to have re-accumulation of fluid and elevation of white blood cell count while using Vancomycin, and thus an alternative therapy was selected and was found to be successful.

Ceftaroline fosamil is a fifth-generation, broad-spectrum antibiotic that has been shown to have bactericidal activity against gram-negative and gram-positive organisms, including MRSA.^12,14 The literature search revealed cases in which ceftaroline effectively eradicated various MRSA infections, including endocarditis, acute bacterial skin and skin structure infections and even an experimental model against osteomyelitis.^12,14 No evidence of MSRA infected pelvic lymphocele treated with ceftaroline was found upon literature search. One side effect that must be considered is the possibility of thrombocytopenia associated with ceftaroline treatment. ¹² This is especially cumbersome if the patient already has a predisposition for thrombocytopenia from a hepatic disorder. ¹² Our patient did not have a history of liver disease and thus ceftaroline could be considered as a suitable antibiotic choice without the burden of close-monitoring that is required to maintain appropriate vancomycin levels. ¹³ After completing a 4-week course of ceftaroline, 600 mg IV every 12 h, the patient was found to have resolution of the pelvic fluid collection and no return of fever or leukocytosis.

Conclusion

A common complication following RALRP includes the formation of lymphoceles.^3,6 The majority remain asymptomatic but a small percentage can cause symptoms that require surgical intervention and antibiotic therapy.^3,6 This case illustrates a patient presenting 2.5 years after RALRP with fever and leukocytosis of unknown etiology that was found to have a MRSA infected pelvic lymphocele. After two rounds of percutaneous drainage, and 4 weeks of therapy with ceftaroline, a complete resolution of symptoms was achieved. Thus it is important for physicians to remain vigilant for evidence of infected pelvic lymphoceles in any patient that has undergone a RALRP regardless of the time that has elapsed.