Quantifying Lymph Nodes During Lymph Node Transplantation

Abstract

Quantifying lymph nodes in vascularized lymph node transfer (VLNT) has been performed using preoperative percutaneous ultrasound. The higher resolution and accuracy of intraoperative ultrasound (IOUS) over transcutaneous ultrasound has been demonstrated in the radiology literature for the identification and characterization of finer structures including hepatic lesions, pancreatic lesions, and biliary or pancreatic ducts. We hypothesize that IOUS during VLNT would be a superior method to quantify and map lymph nodes in our flaps. A prospectively collected database of patients undergoing VLNT over 3 years (October 2014 to October 2017) was reviewed. Patients who underwent IOUS during flap harvest, before pedicle ligation to simultaneously map and quantify the number of lymph nodes were included in the study. Twenty-one patients with an average age of 58.7 years and a mean BMI of 32.3 underwent VLNT with IOUS for chronic lymphedema during the study period. Extremity lymphedema was classified as Campisi IB (n = 7), IIA (n = 7), IIB (n = 5), and IIIA (n = 2). There were 14 superficial circumflex iliac artery flaps, including 4 performed concomitantly with a deep inferior epigastric perforator flap, 1 transverse cervical artery flap, and 6 omental flaps. The average number of lymph nodes transferred per IOUS was 4.3 for superficial circumflex iliac artery flaps, 4 for the transverse cervical artery flap, and 5.2 for the omental flaps. Intraoperative ultrasound allows the lymphatic surgeon to precisely map the location of lymph nodes which can guide intraoperative decision making. As there is no data correlating the number of lymph nodes transferred and outcomes after VLNT, developing a precise intraoperative quantification method is important.

Flow-through Omental Flap for Vascularized Lymph Node Transfer: A Novel Surgical Approach for Delayed Lymphatic Reconstruction

“…9 That is, arterial inflow to the transferred tissue was significant enough to result in decreased peripheral flow to the extremity. A porcine study of the omental flow-through flap demonstrated that flow dynamics were unchanged at the distal arterial anastomosis 7 even when the omental flap was clamped. 10 Thus, in a flow-through configuration, the arterial inflow to the flap is significantly less than in an end-to-side configuration.…”

“…used intraoperative ultrasound (IOUS) to identify and quantify lymph nodes as previously described. 7 The omentum was harvested and the proximal and distal gastroepiploic vessels were identified.…”

The Boston lymphatic center’s early experience with lymph node transplantation to the upper extremity

“…The time interval from lymphedema diagnosis to the initial surgical consultation appeared to be shorter in the fluid-dominant cohort with a median of 2 (1-4) years compared to the fat-dominant group at 8 (5-15) years. For lymphedema patients with fat-dominant disease, the median time from debulking to VLNT was 18 (16)(17)(18)(19)(20)(21) months. For all patients, the median flap weight was 23 (18-28) grams with a median of 6 (5-7) lymph nodes transferred, as identified on intraoperative ultrasound.…”

“…The number of lymph nodes within the flap and the overall flap weight were recorded. Our intraoperative duplex ultrasound process for lymph node identification and quantification during VLNT has previously been described in detail [ 22 , 23 ] .…”

“…Institutional review board approval was obtained for this study (Protocol #2022P000092). A review of a prospectively maintained REDCap Quality Improvement Database [21] and a medical review were performed. Patients who underwent vascularized omental lymph node transplant for the treatment of upper extremity lymphedema from May 2017 to April 2022 were identified.…”