Management of Pediatric Tumors With Vascular Extension

Abstract

Background: Pediatric tumors can present with vascular extension to the inferior vena cava and right atrium, which impacts the surgical strategy and can be challenging during surgical treatment. Wilms tumor (WT) is the most common retroperitoneal tumor that can present with vascular extension, but also adrenal tumors, clear cell tumors from the kidney, and hepatoblastomas can present with this situation. Surgical aims include obtaining complete tumor resection without risk for patients, to avoid severe bleeding, cardiac arrest, and embolization, and to avoid cardiac bypass if possible.Objective: To describe and discuss the surgical strategies to deal with pediatric tumors with vascular extension and propose a protocol.Method: Retrospectivly review the experience of treating patients with vascular extension in a single institution, describing different scenarios and a decision making fluxogram based on the preoperative evaluation regarding the surgical techniques and the need for cardiac bypass that are adequate for each situation. Image studies are important to guide the surgical strategy. Depending on the quality of image available, computerized tomography (CT) or magnetic resonance imaging (MRI) can be enough to give the information needed for surgical decisions. Ultrasonography (US) with Doppler is helpful to confirm diagnosis and describes factors to guide the adequate surgical strategy, like the upper level extension and presence or absence of blood flow around the thrombus. Neoadjuvant chemotherapy is indicated in most cases, in order to reduce the upper level of extension (and avoid the need for cardiac bypass) and to lower the risk of embolization. The approach is based on the upper level of the thrombus and can include cavotomy or cavectomy, sometimes with cardiac bypass and cardiac arrest with hypothermia, when the thrombus reaches the diaphragmatic level or above. Pathology analysis of the thrombus can guide staging and the need for radiotherapy postoperatively.Results: A decision making fluxogram protocol is presented focusing on the surgical treatment of such condition.Conclusion: Surgery strategy is highly impacted by the presence of vascular extension in pediatric tumors. Surgeons should be aware of potential complications and how to prevent them. Such cases should be treated in reference centers.

Intravascular Tumor Extension and Pulmonary Tumor Embolism in Children With Solid Malignancies: Is There a Role for Inferior Vena Cava Filters?

“…Although no unified approach to intravascular tumors exists in children, the mainstay of treatment is neoadjuvant chemotherapy and surgery 8 . Other management options have been described, but to date, no guidelines have been adopted.…”

“…Although no unified approach to intravascular tumors exists in children, the mainstay of treatment is neoadjuvant chemotherapy and surgery. 8 Other management options have been described, but to date, no guidelines have been adopted. Given our experience, we propose that IVC filter placement may reduce the risk of significant pulmonary tumor embolus in children with pelvic tumors and intravascular extension to the IVC.…”

Current trends and prospects of surgical techniques for hepatoblastoma

“…Using their strategy, extracorporeal circulation does not need to be established for subphrenic tumor thrombi, which can be removed by first controlling and transecting the blood vessels. Alternatively, part of the involved blood vessels can be removed for vascular reconstruction or replacement 26 . For tumor thrombi at the diaphragm level, extracorporeal circulation should be established, whereas tumor thrombi above the diaphragm require surgery under cardiopulmonary bypass with cardiac arrest.…”

Multidisciplinary Treatment Strategies for Wilms Tumor: Recent Advances, Technical Innovations and Future Directions

“…A complete picture of a possible intravascular extension is essential for planning anesthesia and surgery. For example, an extensive tumor thrombus to the cardiac atrium may lead to cardiac deprivation and the need for cardiopulmonary bypass surgery for its resection ( 31 , 56 , 58 ). As the venous tumor extension is not always seen on preoperative imaging, intraoperative exploration by manual palpation and/or ultrasonography of the renal vein is mandatory.…”

“…Contrast MRI (or CT) and ultrasound examinations will need to assess extension of the tumor into the renal vein and vena cava. Echocardiography is warranted to assess heart function and the venous extension of a tumor thrombus into the atrium (31)(32)(33).…”