Resection of the Inferior Vena Cava Due to Tumor Involvement

Data Collection:

Investigators retrospectively looked at patients who, from January 2012 to December 2018, underwent surgical procedures in the unit for IVC-specific tumors or for IVC resections due to secondary infiltrative tumors. In some cases, the IVC involvement was an intraoperative finding.

Patients with primary or secondary IVC involvement who underwent surgery were included in the study. Patients with metastasis found during intraoperative exploration were excluded from the study.

Diagnostic management included establishment of a medical history, performance of clinical examination and imaging tests, including an abdominal ultrasound and computerized tomography (CT) scan, to confirm the tumor origin and growth, as well as infiltration, if any, of adjacent structures. These also allowed to rule out distant metastases, and to assess resectability and the option for vascular reconstruction. In some cases, the decision to resect the IVC was made during surgery, because IVC involvement was an intraoperative finding which remained unknown up to that point.

The variables taken into account were age, sex, BMI, the American Society of Anesthesiologists (ASA) classification, tumor type, preoperative chemotherapy and/or radiation therapy. In addition, another variable considered was whether the finding was intraoperative or preoperative. Perioperative clinical results, surgical approach, type of IVC resection and reconstruction, and intraoperative complications were recorded. Details of the postoperative course were collected. Some of the key short-term data recorded included length of hospital stay, complications' ranking (according to the Clavien-Dindo score; 'severe complication' is defined as greater or equal to IIIa), re-operation, re-admission and operative mortality (< 90 days after operation). Some of the key long-term data recorded were patency of IVC or prosthesis (as determined by a CT scan), neoadjuvant and adjuvant chemotherapy, specific disease-free survival and overall survival (OS).

Surgical Approach Management of IVC involvement was categorized in three groups, according to the surgical repair necessary: resection with primary repair, resection with autologous or prosthetic patch repair, and circumferential resection with graft replacement. Primary repair was defined as resection of a portion of the IVC with primary closure when <50% narrowing of the lumen would result. Patch closure was planned when a larger defect created by the resection required patch repair to avoid narrowing of the IVC. Circumferential resection of the IVC was managed with replacement using a prosthetic graft.

For surgical planning, investigators used the classification according to Kulayat, which subdivides the IVC into three segments: upper portion (level 1)-extending from the opening of the hepatic veins up to the right atrium-, middle portion (level 2)-extending from the renal veins to the hepatic veins-, and lower portion (level 3)-extending from the junction of the iliac veins to the opening of the renal veins.

Intravenous heparin was not used during the clamping time of the IVC. Heparinized saline (2units/ml of heparin sodium) was used, however, to flush out the prosthesis if being used for reconstruction. A therapeutic heparin dose is used for 30 days after surgery, and patients with prosthesis receive oral blood thinners for at least six months.

Follow-up Patient follow-up included measuring tumor markers and performing a chest-abdominal CT scan every three months for the first two years; then, twice a year; and then, annually, after five years. Local recurrence was defined as a return of a tumor within the surgical field, whereas systemic recurrence was defined as recurrent disease outside said field.

Inclusion criteria

• Patients with primary or secondary IVC involvement who underwent surgery.

Exclusion criteria

• Patients with metastasis found during intraoperative exploration.