Resecting Lower Segment Inferior Vena Cava Leiomyosarcoma With Middle Segment Extension While Avoiding Renal Morbidity

Introduction

Primary leiomyosarcoma of the inferior vena cava (IVC) is rare and aggressive mesenchymal tumor originating from the endothelial smooth muscle of the intima, known for both intra‐ and extraluminal growth patterns. ¹ Due to its rarity, most information about treatment comes from case reports or small series, and complete resection of the tumor with negative margins is the only therapeutical option that has demonstrated a survival benefit. The most commonly used classification scheme dividing the IVC leiomyosarcoma (LMS) into upper segment (above hepatic veins), middle segment (between hepatic veins and renal veins) and lower segment (below renal veins) reflects the importance of the major branches of the IVC in dictating operative approach and resectability of the tumor. ² In addition, management of the IVC after tumor resection is controversial, and primary repair, ligation or reconstruction of the IVC have all been utilized with variable results. We report a successful case of resecting and reconstructing a lower segment IVC leiomyosarcoma with middle segment extension in a 65-year-old female, avoiding renal reimplantation or nephrectomy-related morbidity.

Case Report

A 65-year-old female with type 2 diabetes and hypertension, and no significant family history, presented with on and off fever and weakness for three months. She was initially being symptomatically managed at civil but no cause for the fever could be defined. Haematological profile was suggestive of anaemia. USG abdomen revealed heterogenous hypoechoic lobulated lesion measuring∼7.5 × 5.0 cm seen in retroperitoneum - possibly in the region of pancreatic head with rest of the pancreas normal in size and echotexture.

For better characterisation of the lesion and organ of origin, a triple phase contrast enhanced computed tomography (CECT) abdomen and pelvis was performed which showed evidence of dilatation of suprarenal, renal and infra-renal segments of the IVC with evidence of lobulated extra-luminal, intra-luminal soft tissue mass lesion seen in association with IVC, measuring up to 5.7 × 6.4 × 5.7 cm (Tr x AP x CC) with evidence of hypodensity seen within the IVC in the suprarenal, renal extending to the bifurcation and left common iliac vein – suggestive of intraluminal thrombus with no evidence of vessel wall infiltration. Anteriorly, the soft tissue mass was seen abutting the 3rd part of duodenum and pancreas with suspicious loss of fat planes. Medially, abutting the aorta, however no evidence of intraluminal extension was seen. Hepatic IVC was normal in contrast opacification with likely impression of IVC Leiomyosarcoma (Figure 1(a)-(c)).

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Figure 1.

Preoperative images. (a-c) Triple phase CECT Abdomen and pelvis showing lobulated extra-luminal, intra-luminal soft tissue mass lesion seen in association with IVC, measuring 5.7 × 6.4 × 5.7 cm with evidence of hypodensity within IVC extending from suprarenal to left common iliac vein, indicating intraluminal thrombus in axial, sagittal, and coronal views.

Contrast enhanced magnetic resonance imaging (MRI) abdomen confirmed the CT findings with the tumor thrombus extending cranially just above the region of suprarenal for a distance of about 2 cm. Caudally the lesion was extending up to the bifurcation and proximal portion of iliac veins. The mass appeared to be extending to the right as well as left renal vein (left > right). However, no invasion was seen. PET-CT suggested localized disease with no disease elsewhere in the body. Additionally, CT Venography and bilateral lower limb venous doppler was performed to rule out any aberrant venous anatomy and deep vein thrombosis (DVT) respectively. Retroperitoneal mass biopsy revealed low grade IVC leiomyosarcoma grade I with vimentin, desmin and SMA diffusely strong positive while Pan CK, S-100, LCA, synaptophysin, chromogranin and beta catenin negative.

The multidisciplinary tumor board convened to plan IVC segmental resection and reconstruction, considering left nephrectomy and right renal reimplantation. The patient was prehabilitated and counselled regarding the procedure, local recurrence rates and the potential for preserving both kidneys and performing a tumor thrombectomy also.

The patient underwent exploratory laparotomy followed by Cattell‐Braasch manoeuvre and kocherisation to mobilize the entire right colon, duodenum, and head of the pancreas to expose the infrahepatic IVC, iliac veins, and bilateral renal vessels. The lateral attachment of the hepatic right lobe was incised to expose the retrohepatic IVC. The gastrohepatic ligament was divided and porta hepatis was encircled with a vessel loop. Short hepatic veins were ligated in order to mobilize the liver from the IVC and gain proximal control over the infrahepatic IVC above the level of thrombus. The extraluminal growth was dissected and mobilised from all the surrounding structures. Similarly bilateral renal vessels, bilateral common iliac vessels and ureters were looped. Lumbar branches on the infrarenal IVC were ligated, allowing access to the retrocaval region. Dissection in the aortocaval space freed the aorta from the tumor. Systemic heparin was administered before clamping the IVC and common iliac veins. Following assessment of the common iliac vein thrombus extent, the veins were clamped and cut. The extraluminal growth, along with the infrarenal segment of the IVC, was lifted en-bloc. A vascular clamp was positioned above the thrombus level in the infrahepatic IVC. A circumferential incision below the renal vein junction was made, ensuring no tumor disruption and tumor thrombectomy was done (Figure 2(a)-(c)).

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Figure 2.

Intraoperative images. (a) Cattell‐Braasch manoeuvre and kocherisation to expose the exophytic growth (blue arrow) arising from IVC (b) Lateral attachment of hepatic right lobe incised and short hepatic veins ligated (c) Vascular clamp placed in infrahepatic IVC, above the level of the thrombus and circumferential incision made in the IVC wall just below the renal veins junction (d-f) IVC reconstructed using Y shaped expanded PTFE graft (g) Gross specimen.

After complete excision, the intraluminal IVC was inspected for residual tumor. The vascular clamp was repositioned in the infrarenal segment to restore renal perfusion. Proximal and distal margins were sent for frozen section. The IVC was reconstructed using Y shaped 16 mm expanded polytetrafluoroethylene (PTFE) graft sewn end‐to‐end to the proximal end of IVC and the bilateral common iliac veins. The flow was restored, adequate haemostasis was achieved and the patient’s incision was closed in standard fashion (Figure 2(d)-(f)).

Postoperatively, the patient had sufficient urine output and received anticoagulant therapy. She developed DVT in the right lower limb, which resolved with conservative management and anticoagulants. Discharged on 15^th postoperative day, the patient was stable. The patient has remained disease-free during the past year’s follow-up (Figure 3).

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Figure 3.

One-year follow-up CT abdomen axial images reveal the PTFE graft in situ (red arrow), with no evidence of disease elsewhere in the abdominal cavity.

The specimen examination revealed a 9 cm segment of the IVC with a solid exophytic growth measuring 6 × 4.5 × 4 cm on the antero-lateral wall. Positioned 2 cm and 1.5 cm away from the proximal and distal margins respectively, the growth displayed intraluminal tumor thrombus (Figure 2(g)). Histopathological analysis depicted spindle cells in intersecting bundles with blunt-ended nuclei and moderate to abundant eosinophilic cytoplasm. Immunohistochemistry revealed positivity for Vimentin and SMA, and negativity for Pan CK, S-100, and Beta-catenin, confirming the diagnosis of IVC Leiomyosarcoma pT2, FNCLCC Grade III, with clear margins and no lymph node involvement (0/8) (Figure 4(a)-(c)). Given the high grade, the patient underwent adjuvant radiotherapy followed by systemic chemotherapy.

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Figure 4.

Postoperative HPE images. (a) H&E stain, 20x view revealed spindle shaped tumor cells arranged in intersecting bundles and fascicles with blunt ended nuclei and moderate to abundant eosinophilic cytoplasm. (b, c) IHC showing SMA and Vimentin positive respectively.

Discussion

IVC leiomyosarcomas are extremely rare tumors, with less than 400 cases reported since their discovery by Perl in 1871. ³ Complete resection of the tumor with clear margins is the only proven curative treatment for IVC LMS. The use of adjuvant radiation and chemotherapy remains controversial and uncertain. ⁴

Due to the varying anatomical involvement of the tumor, different surgical resection techniques and approaches have been utilized. Nevertheless, in all previous case series focusing on the middle segment of IVC LMS, it has consistently been noted that preventing the need for renal reimplantation or nephrectomy is extremely challenging when aiming for R0 resection. The prior literature has reported nephrectomy rates ranging from 56% to 75%. ⁵ Despite careful surgical efforts, post-operative renal failure in reimplanted kidneys remains a well-documented complication.

Our case report demonstrates successful salvage of both kidneys through tumor thrombectomy. Advanced radiological techniques, including CT and MRI, accurately depicted the extent of IVC leiomyosarcoma, aiding in precise preoperative planning and reducing surgical morbidity and duration. ⁶ A collaborative approach with surgical oncologists, vascular surgeons, and radiologists is the key. Post-IVC resection management (primary repair, ligation, or reconstruction) depends on lesion extent, renal vein outflow through collaterals, pre-operative renal function, and patient performance status. Reported perioperative mortality for primary IVC leiomyosarcoma resection ranges from 0% to 15%. ⁷

It is important to acknowledge that this above-mentioned approach is applicable in thoroughly investigated patients with compromised renal function and no evidence of vessel wall invasion on imaging. After tumor resection and thrombus removal, careful evaluation of intraluminal disease, specimen and frozen section analysis of margins are imperative. While not employed in this instance, intraoperative ultrasound can serve as a supplementary tool to exclude the chance of R1 resection. However, this approach comes with the caveat of necessitating an experienced radiologist during the surgery.

In cases of an extensive tumor thrombus, there’s always uncertainty about conclusively ruling out an R1 resection through above mentioned techniques. However, due to the patient’s age, disease extent, compromised renal function, and the lack of alternative curative treatments, choosing proximal resection above the renal veins followed by renal implantation would have carried significant risks of intraoperative mortality and postoperative morbidity and mortality.

Conclusion

Our novel approach embraces the concept of present era of minimal surgery without compromising oncological outcomes and prioritizes patient well-being, quality of life, and functional preservation.