A. E. Felsted1, Y. Shi1, P. M. Masand2,4, J. Goss1,5,6, J. G. Nuchtern1,3, S. A. Vasudevan1,3 1Baylor College Of Medicine,Michael E. DeBakey Department Of Surgery,Houston, TX, USA 2Baylor College Of Medicine,Department Of Radiology,Houston, TX, USA 3Texas Children’s Hospital,Pediatric Surgery,Houston, TX, USA 4Texas Children’s Hospital,Pediatric Radiology,Houston, TX, USA 5Texas Children’s Hospital,Transplantation Program,Houston, TX, USA 6Michael E. DeBakey Veterans Affairs Medical Center,Liver Transplantation,Houston, TX, USA
Introduction:
Primary hepatic tumors are rare in children. While approximately two thirds of these tumors are malignant, they account for only 1.1% of childhood malignancies annually. Surgical resection or liver transplantation are the primary curative treatments for primary malignant pediatric liver tumors. When sufficiently symptomatic, benign liver lesions may also necessitate resection. Pre-operative imaging (POI) including multidetector CT and liver MRI are critical in assessing disease extent and surgical planning. The use of intraoperative ultrasound (IOUS) as an adjunct to POI in guiding surgical management of adult liver tumors is well-documented, but has not been well-studied pediatric liver tumors. We report here a single center’s experience with POI and IOUS in resection of pediatric primary liver tumors.
Methods:
The medical records of 22 pediatric patients diagnosed with primary liver tumors and scheduled for resection between 2003 and 2014 at one institution were reviewed to determine the utility of IOUS in pediatric liver resection. IOUS finding were compared with the patients’ pre-operative MRI and/or MDCT studies. Changes in surgical management based on IOUS findings were also noted.
Results:
Of the 22 patients reviewed, 16 were evaluated using IOUS. Of those 16 evaluated with IOUS, five patients had discordant findings. In two of these cases, MRI overestimated the tumor involvement in segment IV. IOUS showed no extension into segment IV in one case and very slight involvement of segment IVa in the other. In both instances the surgeon then was able to perform a left lateral hepatectomy rather than a left hepatectomy. In the third patient, IOUS revealed tumor extension into segment IVb which was not seen on MRI. Adenomatosis was discovered in one patient believed to have a single adenoma. An additional lesion was then biopsied, confirmed an adenoma, and resection continued as planned. In the last patient MRI showed a displaced but uninvolved right hepatic vein, but on IOUS the tumor clearly surrounded the vein necessitating a formal right hepatectomy. In four other cases IOUS was necessary to identify unusual vascular anatomy or determine resection margins. Two cases were aborted after IOUS confirmed the extent of disease and proximity to critical vessels. Vascular margins on POI and IOUS were also compared for tumors less than 2 cm from major vessels. In the 12 evaluated margins nine measurements differed less than 1 mm and three differed between 1 and 4 mm.
Conclusion:
Use of IOUS in surgical management of primary pediatric liver tumors has not been universally adopted to date. We found IOUS and POI to be equivalent when assessing tumor-to-vessel margins. However, IOUS findings altered surgical management in multiple cases – particularly when evaluating tumor involvement of segment IV. Thus, IOUS should be considered a useful adjunct to POI for surgical management of pediatric primary liver tumor.