Calcification of the Renal Vein and Inferior Vena Cava on a Renal Tumor: An Exceptional Case

Background: A thrombus of the inferior vena cava and renal vein makes the management of renal cancer more difficult. Aim: The aim is to highlight and discuss the management of a case of renal cancer with an unusual thrombus in our context. Case Presentation: We report the case of a 49-year-old female with left kidney cancer, complicated by a calcified thrombus of the renal vein and inferior vena cava. A calcification of renal vein and vena cava was discovered during surgery, even though the diagnosis prior to surgery was a renal tumor with partial thrombus of the IVC. We performed a thrombectomy and left nephrectomy. The post-operative course was marked by the death of the patient a month later. Conclusion: Renal vein and inferior vena cava (IVC) calcifications are uncommon. Preoperative diagnosis is difficult but guided by medical imaging. Renal cancer is one of the causes. A thrombus or calcification of the vena cava worsens the prognosis of cancer.


Introduction
Most renal tumors are cancers. Renal cancer is the third urological cancer after prostate and bladder and represents about 3% of adult cancer. Due to the anatomic position of the kidney, renal cancer has a long latency, and the discovery is done luckily during investigations for another reason. Most of the time it is done at a metastatic stage. During its progression, cancer will cross the kidney capsule, invade peri renal fat and spread into lymph nodes, renal vein and inferior vena cava (IVC). A thrombus of the IVC during the course of renal cancer is infrequent (2 -10%). The occurrence of calcification of the inferior vena cava (IVC) with a kidney tumor is more difficult to find [1] [2]. Few cases have been reported in literacy. In Côte d'Ivoire, no case has been previously reported. We are presenting the case of a patient whose IVC calcification was suspected by the computed tomography scan and confirmed during the surgery. The aim of this report was to emphasize the morbidity and mortality and difficult management of such cases in the underequipped area. Informed consent was obtained from the family to report this case.

Case Report
The patient was a 49 years old female, known to be hypertensive and was being followed. She came to us with an abdominal mass. The onset of the signs occurred about 4 months ago, with a progressive worsening left lumbar pain. It was described as a permanent constriction, with a paroxysmal episode, without any triggering factor or objective sedation. There was no hematuria or burning of the urine. She consulted a community health centre where the diagnosis of lumbar osteoarthritis was made, with the introduction of analgesic treatment.
Given the persistence of the signs, she consulted a private care unit where scannographic and biological explorations were performed. She was then referred to us for care.
She had a major history of undocumented exploratory laparotomy. There was no notion of previous nephropathy or exposure to hydrocarbons. We also noted the absence of personal or familial venous thromboembolic disease. She had 4 children. She was menopausal without any notion of metrorrhagia.
On admission, she was vigilant, with a WHO score of 1. The conjunctiva were stained, there was no edema of the lower limbs. Blood pressure was 140/100 mmHg with a pulse rate of 79/minute. There was a median laparotomy scar. The urogenital examination showed a left lumbar curvature with lumbar contact and kidney swelling. The rest of examination was unremarkable. We concluded that it was a left renal tumor syndrome.
Computed tomography scan coupled with study of the kidney vessels objectified a hypervascular tumor of the lower pole of the left kidney with thrombus of the left renal vein and IVC. The upper pole of the thrombus was calcified and its upper level was located at the junction of the suprahepatic veins, corresponding to a level III of the MAYO classification. In addition, a dilatated left gonadal vein was noted ( Figure 1 and Figure 2).
An anticoagulant treatment with low-molecular-weight heparin at a curative dose was instituted preoperatively for 5 days. Our surgical attitude was sequenced as follows. We approached this tumor with a xyphopubic laparotomy.
After detachment of the right Toldt fascia (Figure 3), the IVC was exposed from the confluence of the iliac veins to the subhepatic portion of the renal vessels.    Medical loops were placed around the sub-renal and supra-renal portion of the IVC respectively, but also on the right and left renal veins. After clamping the medical loops (subrenal IVC, right renal vein and then suprarenal IVC) we performed a cavotomy with a cold scalpel and extracted the calcification (Figure 4).
The suture of the IVC was performed with 5-0 non-adsorbable suture. We then did the extended left nephrectomy ( Figure 5).

Discussion
The presence of a renal tumor can usually be correlated with a vena cava thrombus. In our context, CT scan is systematically requested in the assessment of operability of kidney tumors. This is an unprecedented situation as no similar case has been reported in Côte d'Ivoire.
Renal cancer with tumor thrombus is uncommon (2% -10%). The largest cohort in Europe was reported by Manceau and involved 97 patients. This team has 30 years of experience in surgery in renal cancer with thrombus. Its mortality and morbidity were significant [2]. The first observations of calcification of IVC thrombus were described by Morgagni, on autopsy series, about 1769.
These early descriptions were made on abdominal images. The classic appearance is a bullet-shaped calcification [3].    Figure 6) [4]. The location of the top of the thrombus is so important that it may be necessary to use MRI for that.
There is no general consensus or guidelines for the treatment of this condition. In general, long-term anticoagulation has been recommended for patients with symptoms of pulmonary embolism or systemic embolization [5]. In our case, the anticoagulant treatment was started immediately preoperatively at a curative dose on the instruction of the cardiologist and stopped 48 hours before the surgical procedure. Level 0, thrombus extending to the renal vein only; level I, thrombus extending into the IVC to no more than 2 cm above the renal vein; level II, thrombus extending into the IVC to more than 2 cm above the renal vein but not to the hepatic vein; level III, thrombus extending into the IVC to above the hepatic vein but not to the diaphragm; and level IV, thrombus extending into the supradiaphragmatic IVC or right atrium [4]. Open Journal of Urology

Conclusion
The prognosis of kidney tumor with IVC thrombus is poor and associated calcification remains exceptional. The prognosis is poor, however, some studies have demonstrated an improvement in the prognosis by surgical treatment.