Whenever possible, the goal of surgical extirpation of abdominal solid organ tumors should be oncologic cure. This assumption presupposes tumor localization to a distinct anatomic region that will allow for resection with negative macroscopic and microscopic margins. Thus, the goals of the procedure should be clearly defined by sufficient preoperative high-quality anatomic cross-sectional imaging, multidisciplinary consultation, and discussions with the patient regarding the operative risks, benefits, expectant outcomes, and overall prognosis.^2,6

Abdominal solid organ tumors are traditionally considered unresectable when they involve the arterial or venous vasculature, are diffusely metastatic throughout the peritoneum or at remote sites, or involve the root of the mesentery or spinal cord to a significant extent. Patients with extensive tumor burden precluding resection may still be offered incomplete removal or debulking operations to potentially prolong survival and improve symptom palliation.⁶

Equally as important as the anatomic considerations, preoperative patient functional status is a significant determinant of surgical eligibility. Performance assessments, such as outlined by the Karnofsky or Eastern Cooperative Oncology Group (ECOG) score, help predict patient-specific postoperative quality of life.^2,7 At our institution, patients who are bedridden at the time of initial assessment, severely disabled, or unable to independently perform activities of self-care are often not offered curative resection.

Candidacy for intraabdominal vascular reconstruction is also contingent on the extent of potential or preexisting vascular compromise. As such, we have typically attempted arterial reconstruction when tumors involve critical arterial structures such as the aorta, celiac artery and its branches, proximal superior mesenteric artery (SMA), common/external iliac artery, and the internal iliac artery in the setting of an embolized, occluded, or resected contralateral internal iliac artery. Similarly, venous reconstruction is also anticipated when tumors margins appear to include the vena cava, portal, superior mesenteric, common, and external iliac veins.

Items to consider in preoperative multidisciplinary review include the extent of planned gross surgical resection margins, the need for preoperative arterial or venous embolization, the need for other prophylactic procedures such as placement of ureteral stents or nephrostomy tubes, and the likelihood for intestinal resection and/or reconstruction.

Ureteral stent placement should be considered in all patients who demonstrate evidence of ureteral obstruction, renal hydronephrosis, or urinary obstructive signs or symptoms from either tumor mass effect or invasion of urologic structures. Moreover, ureteral stents should also be considered in patients with pelvic tumors where there is potential concern of ureteral injury during resection of the tumor or during vascular reconstruction.

A thorough review of detailed preoperative imaging will greatly facilitate proper conduit selection and preparation and, ultimately, a successful outcome. Particular attention should be directed to the length of vascular segment involved by adjacent tumor, the branch points and bifurcations present along this length, and which segments, if any, are circumferentially encased by tumor parenchyma.

Attention should be paid as to whether planned resection will include vessels which are already occluded with adequate collateral circulation already in place, or whether adjacent or contralateral vascular structures are capable of supplying adequate inflow and outflow. Vascular segments to be reconstructed should be patent and preserved to the greatest extent possible during the planned tumor resection.

Endovascular embolization is the preferred method of preoperative vascular occlusion prior to open surgical resection. This strategy is commonly used for preoperative splenic artery/vein embolization prior to planned surgical splenectomy, internal iliac artery embolization prior to planned pelvic
tumor resection, and renal artery/vein embolization prior to planned nephrectomy with or without the need for further exposure of the retrohepatic IVC. For this purpose, the preferred size of coils/plugs is estimated based on the diameter and length measurements of the target vessel on preoperative cross-sectional imaging and is typically oversized by up to 20% of the target vessel diameter. For additional details regarding visceral embolization techniques, refer to Part 6, Chapter 19 (Stenting, Endografting, and Embolization Techniques: Celiac, Mesenteric, Splenic, Hepatic, and Renal Artery Disease Management). For additional details regarding internal iliac artery embolization techniques, refer to Part 6, Chapter 24 (Advanced Aneurysm Management Techniques: Management of Internal Iliac Aneurysm Disease).

Aortoiliac arterial involvement often requires resection followed by reconstruction with patch angioplasty, interposition, or extraanatomic bypass. Type of reconstruction and conduit type (autogenous venous allograft, cryopreserved homograft, or synthetic conduit) is contingent on the type of tumor, extent of vascular segment involvement, and degree to which intestinal reconstruction is also anticipated. In the latter case, when contamination by succus entericus is likely, autogenous femoral vein conduits for iliac artery reconstructions and IVC or spliced femoral vein conduits for aortic reconstructions are preferred. Alternatively, when not available, rifampin-soaked, gel-sealed knitted Dacron conduit may serve as a potential substitute with acceptable results.⁸

Reconstruction of the celiac trunk, common hepatic artery, SMA, portal vein, and superior mesenteric vein (SMV) are similarly contingent on the extent of involvement of these structures with tumor pathology. Unless the artery in question is circumferentially involved, it is our preference to resect only the portion of vessel wall directly involved with tumor while preserving the remaining vessel architecture with patch repair. Autogenous venous conduit (using superficial femoral vein or greater saphenous vein or femoral vein) is preferred for vessel segments requiring interposition grafting.

The mainstay of treatment of primary and secondary tumors of the IVC is surgical resection and reconstruction. The extent of reconstruction is contingent on the type of tumor, extent of caval involvement, and the anatomic segments involved. Adequate retrohepatic caval exposure is challenging and may require total vascular isolation of the liver to minimize blood loss during this maneuver. In circumstances where the IVC is chronically occluded with tolerable lower extremity edema and adequate renal function, ligation and resection without reconstruction should be considered. On the other hand, patients with recent occlusion of the IVC, few venous collaterals, notable lower extremity symptoms, or renal insufficiency should be considered for either interposition grafting or patch venoplasty.

Preoperative endovascular embolization procedures should be performed in an angiography suite or hybrid operating room, equipped with a fixed-imaging apparatus, floatingpoint carbon fiber operating table, fluoroscopy platform, and monitor-viewing bank. A full complement of compatible guidewires, catheters, sheaths, coils, and plugs should also be available.

Open tumor operative resection procedures are best performed in an operating room setting with adequate space to facilitate the maneuvering of multiple surgical subspecialty teams and their necessary operative trays/equipment.

Most intraabdominal operative tumor resection and reconstruction procedures may be performed with the patient in the supine position. In the surgical field, the patient’s lower extremities should be prepared for vein harvest if potentially necessary.

In patients who require retrohepatic IVC exposure and reconstruction, the left lateral decubitus position should be employed to facilitate right thoracoabdominal exposure through the 8th or 9th rib interspace.

Placement of ureteral stents will require initial positioning of the patient in lithotomy position and then subsequent repositioning of the patient to facilitate further planned surgical intervention.