Inferior Vena Cava Prosthetic Replacement in a Patient With Horseshoe Kidney and Metastatic Testicular Tumor

Technical Considerations and Review of the Literature

Pietro Rispoli; Paolo Destefanis; Paolo Garneri; Gianfranco Varetto; Beatrice Lillaz; Claudio Castagno; Patrizia Lista; Libero Ciuffreda; Dario Fontana

Disclosures

BMC Urol. 2014;14(40) 

In This Article

Case Presentation

A 22-year-old man underwent right radical orchiectomy for a testicular mass; the histopathological diagnosis was pure teratoma of the testis. Computed Tomography (CT) with contrast material of the abdomen, chest and head for tumor staging showed metastases to the liver, lungs, retroperitoneal lymph nodes, and brain. The imaging studies also revealed a right laterocaval retroperitoneal mass (largest diameter 7 × 9 cm) invading the iliopsoas muscle but without clear signs of caval wall infiltration (Figure 1). An incidental imaging discovery was a horseshoe kidney with a parenchymatous isthmus. The level of Beta-Human Chorionic Gonadotropin (BHCG) was 2,250,000 IU/L (normal values <5 IU/L in males) and that of alpha-fetoprotein 2 ng/ml (normal values <10 ng/ml in adult males).

Figure 1.

Retroperitoneal right laterocaval mass. CT shows the coexistence of a horseshoe kidney (A) and a retroperitoneal right laterocaval mass of the maximum diameter of 7 × 9 cm, indissociable from the iliopsoas muscle and without clear signs of infiltration of the caval wall (B).

The patient subsequently underwent three cycles of chemotherapy with etoposide and cisplatin; a fourth cycle of EP was suspended due to the occurrence of a bacterial endocarditis. After the improvement of clinical conditions, the patient underwent a salvage chemotherapy with four cycles of etoposide, ifosfamide and cisplatin, during which the BHCG level decreased to 86 IU/L. On Positron-Emission Tomography (PET), elevated metabolic activity was absent in the lung and liver lesions but present in the laterocaval retroperitoneal lymph node mass.

On AngioCT prior to surgery for removal of the residual retroperitoneal mass, the mass (largest diameter 5–6 cm) was found to be continuous with the inferior vena cava and extend to the inter-aorto-caval area. The images also showed, besides the known horseshoe kidney, two right renal arteries, one left renal artery, and one renal vein on each side draining into the inferior vena cava.

The retroperitoneal mass was removed via transperitoneal surgical access. After a puboxiphoid incision and V opening of the retroperitoneal cavity, the right side of the horseshoe kidney and the two right renal arteries were isolated. The retroperitoneal lymphatic mass (largest diameter about 6 cm) was found to infiltrate the psoas muscle and the lateral wall of the inferior vena cava along its entire thickness for about 5 cm, from the segment underneath the renal isthmus till 3–4 cm from the iliocaval confluence (Figure 2).

Figure 2.

Horseshoe kidney and cava vein. The retroperitoneal mass, of diameter of about 6 cm, was infiltrating the psoas muscle and also the lateral wall of the cava vein that was interested in full-thickness to about 5 cm of extension, from its portion below the isthmus renal up to 3–4 cm from the ileo-caval confluence.

The right external iliac lymph nodes, laterocaval, interaortocaval and presacral lymph nodes were removed. The right side of the horseshoe kidney was dislodged from the posterior planes of the abdominal cavity, flipped superomedially en bloc with its vascular structures to expose the mass (Figure 3). The lymph node mass infiltrating the caval wall was removed (Figures 4, 5, 6, 7) and an approximately 10 cm long section of the inferior vena cava was replaced with a ringed PTFE (PolyTetraFluoroEthylene) graft (16 mm) (Figure 8). Anticoagulant therapy with low-molecular weight heparin at the therapeutic dose was initiated. Final pathology showed tumor necrosis comprehending a small area of chondroid vital tissue for the mass infiltrating inferior vena cava and psoas muscle. All other resected lymph-nodes resulted negative.

Figure 3.

The caval lymph-node dissection begins. The right side of the horseshoe kidney was dislodged from the posterior planes of the abdominal cavity, flipped superomedially en bloc with its vascular structures to expose the mass.

Figure 4.

The caval mass is dissected, but it infiltrates the psoas muscle that is partially sectioned with the mass.

Figure 5.

During the dissection, an attempt to free the cava vein from the mass is made, but the caval wall is massively infiltrated by the lesion.

Figure 6.

The segment of inferior vena cava infiltrated by the mass is then removed.

Figure 7.

The operative field after the complete removal of the residual mass, the inferior vena cava and a part of psoas muscle.

Figure 8.

Cava prosthetic replacement. Removal of the mass infiltrating the wall of the vena cava and inferior vena cava replacement for a section of about 10 cm with a 16 mm ringed PTFE prosthesis.

Control CT at 1 month postoperative showed graft and inferior vena cava patency, a reduction of about 20% in the volume of the lung lesions as compared to the CT scan obtained before chemotherapy, and no recurrence of neoplastic abdominal tissue. The graft patency and absence of abdominal neoplastic tissue was confirmed at 1 year AngioCT (Figure 9).

Figure 9.

Follow up imaging. The control CT at 1 year (A and B) demonstrates the absence of the lesion and the patency of the prosthesis.

The patient then underwent removal of the brain metastases secondary to GCT with choriocarcinomatous features, followed by one cycle of chemotherapy with paclitaxel, ifosfamide, and cisplatin. At 18 months the patient underwent resection of bilateral lung lesions. At 2 years follow-up, the patients was in good health and virtually disease free (normal value of tumor markers). Control AngioCT confirmed transformation of the liver lesions into cysts. The inferior vena cava and the graft were both patent, and no signs of renal insufficiency were noted. The patient is still under oral anticoagulant therapy. Renal function was unchanged as compared to pretreatment status.

Discussion

The International Germ Cell Cancer Collaborative Group (IGCCCG) classifies GCT as a tumor having good, medium, or poor prognosis on the basis of variables including primary tumor site, presence or absence of metastases, levels of AFP (Alpha-FetoProtein), BHCG, and LDH.[2] In view of these variables, the GCT in our patient was classified as carrying a poor prognosis owing to the presence of extrapulmonary lesions and the extremely high level of BHCG (2,250,000 IU/L) at diagnosis. According to the guidelines of the European Association of Urology (March 2011) and the National Comprehension Cancer Network (NCCN 2012), in cases of non-seminomatous GCT treated with orchiectomy and chemotherapy but with residual retroperitoneal lymph nodes >1 cm, removal of the residual mass is warranted and defined as "desperation surgery" in some cases.[7,8] Of fundamental importance is radical surgery,[9] with ad hoc vascular surgery procedures for caval and aortic replacement.[4]

Recent studies have shown that about 7% of patients who had received post-chemotherapy retroperitoneal lymph node dissection will require resection of the IVC[10] because of tumoral infiltration into the cava. Recently, Winter et al. evaluated 339 cases with an absolute indication of residual tumor resection after chemotherapy in patients with advanced stage GCT. Surgery of the IVC was necessary in 34 patients (about 10%), in 56% of which vena cava resection and graft placement were required. Resection and interruption of the IVC without reconstruction is possible only in cases of previous caval obstruction and the formation of collaterals which provide for sufficient venous drainage. No complications, e.g., lower limb oedema, decreased renal function, developed in any of the patients undergoing graft reconstruction of the IVC.[11] However, Gloviczki et al. reported a 54% patency rate at 2 years after iliacocaval reconstruction with PTFE grafts.[12]

An alternative to grafting may be primary ligation of the IVC without replacement of the removed segment; however, this is associated with a higher post-operative complications rate, a mortality rate of 9%, and severe lower limbs oedema in 36% of cases. Symptoms secondary to chronic venous insufficiency, including secondary varicose veins of the lower limbs, scrotum and abdomen, have been reported in up to 50% of cases. A recent study in 47 patients undergoing caval replacement for infiltrating tumor showed that graft replacement of the IVC prevents venous complications in the extremities and probably contributes to improving quality of life and survival.[13]

The IVC can also be replaced with autologous veins, but this option is often impractical because of the difficulty in harvesting enough homologous material to substitute a long venous segment. Spiral vein grafts are not recommended owing to the elevated thrombogenicity of the surface exposed at the suture sites and the high risk of veins collapsing due to the positive intra-abdominal pressure.[14] Currently, PTFE grafts are the prosthesis of choice for caval replacement, with ringed grafts best able to prevent side effects during the immediate post-operative period and symptoms of chronic venous insufficiency.[10,15]

In the case presented here, caval replacement was carried out in the context of a particular anatomic setting: horseshoe kidney. Central fusion of the kidneys occurs when the embryo is 5 to 12 mm, i.e., when the kidneys lie in the true pelvis. Horseshoe kidney is usually located between L3 and L5, lower than normal, because its ascent is impeded by the root of the inferior mesenteric artery. Also, its normal medial rotation is impeded, frequently resulting in an anomalous course of the ureters, which are often ectopic or retrocaval. The kidneys are fused together by a thick isthmus, generally parenchymatous and very often situated anterior to the aorta and the IVC. More rarely it may be found posterior to these vessels or in the interaortocaval space.

The incidence of horseshoe kidney is between 1/400 and 1/800 persons, with a male-to-female ratio of about 2:1. In 90% of cases, the kidneys are fused at the lower poles, either symmetrically (midline fusion) or asymmetrically (L-shaped fusion).[16]

The vascular network of horseshoe kidney varies widely:

  1. One renal artery per side (20%)

  2. One renal artery per side with a branch from the aorta to the isthmus (30%)

  3. Two arteries per side with an aortic branch to the isthmus (15%)

  4. Two arteries per side with one or more arteries from the iliac arteries to the isthmus (15%)

  5. Multiple renal arteries originating from the aorta, the iliac and the mesenteric arteries (20%)[17]

Because embryogenesis of the kidney occurs contemporaneously with its venous drainage system in the vena cava, there is a correlation between the presence of horseshoe kidney and venous abnormalities:

  1. Double IVC (0.2–3%)

  2. Postrenal left IVC (0.2–0.5%)

  3. Retroaortic left renal vein (2.1%)

  4. Circumaortic left renal vein (8.7%)

  5. Retrocaval or circumcaval ureters (0.001–0.1%)

  6. Preaortic iliac vein confluence (very rare)[18]

The association between non-seminomatous GCT and horseshoe kidney is a rare event and is seen in about 1.3% of patients requiring retroperitoneal lymph node dissection.[16] To our knowledge, no cases have been reported in which replacement of the IVC was also necessary.

As described by Evans et al.[16] and Sogani et al.,[19] retroperitoneal lymph node dissection in patients with horseshoe kidney demands scrupulous preparation because of the added complexities arising from the vascular abnormalities associated with this congenital disorder. Added to this is the need to avoid resecting the isthmus as it is often composed of functional renal parenchyma and is therefore richly vascularized. Only the resection of a fibrous isthmus should not lead to a reduction in renal function or to immediate complications such as bleeding.

Scheduled caval replacement will entail careful preoperative imaging to evaluate the morphology and functionality of the isthmus of horseshoe kidney, its arterial vascularization and anatomic relationships with the ureters and venous structures. In young patients, the surgical goal is to achieve radical removal. Winter et al.[11] reported that, on the basis of univariate analysis, the residual mass size (>5 cm) and the IGCCCG prognostic class were predictive factors for completing residual tumor resection in procedures involving the IVC (Inferior Vena Cava), thus providing the basic parameters for surgical planning. Also of fundamental importance is to minimize major hemodynamic complication and preserve renal function. Residual tumor resection with additional vascular procedures is burdened by high mortality, with survival rates of about 71% due to the deteriorated physical condition of patients who have undergone several cycles of chemotherapy.[20,21]

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