Page 24 - Read Online

Friedman et al. Plast Aesthet Res 2022;9:58 https://dx.doi.org/10.20517/2347-9264.2022.77 Page 3 of 11

a fat-dominant phenotype.

METHODS
Study design, setting, and population
An observational study was conducted at the Boston Lymphatic Center/Beth Israel Deaconess Medical
Center. Institutional review board approval was obtained for this study (Protocol #2022P000092). A review
of a prospectively maintained REDCap Quality Improvement Database and a medical review were
[21]
performed. Patients who underwent vascularized omental lymph node transplant for the treatment of upper
extremity lymphedema from May 2017 to April 2022 were identified. Patients were included if they had
preoperative measurements, a minimum of 12 months of follow-up, and were treated as per our current
algorithm in which patients with fat-dominant diseases underwent debulking lipectomy prior to VLNT.
Patient demographics, lymphedema characteristics, intraoperative variables, and surveillance data were
extracted for analysis. Baseline characteristics were summarized using means and standard deviations or
medians and interquartile ranges (IQR) for continuous data and counts and percentages for categorical
data. Descriptive data analysis was performed using R version 4.1.3 (R Foundation for Statistical
Computing, Vienna, Austria).

Preoperative evaluation and identification of surgical candidates
Our center’s approach and evaluation of a patient with lymphedema have been previously described .
[18]
Determination of lymphedema phenotype (fluid- versus fat-dominant) was performed by an attending
radiologist (Tsai LL) as part of our standardized algorithm for evaluation of patients presenting to our
center [19,20] . A T2-weighted short-T1 inversion recovery (STIR) image and fat-specific Dixon image were
obtained and utilized to grade the proportion of fatty and fluid tissue in the affected limb. Patients with fat-
dominant disease who underwent prior debulking were evaluated for VLNT at least one year post debulking
lipectomy with stabilized limb volume. Those with a fluid-dominant phenotype were considered for VLNT
alone.

Surgical technique
This surgical procedure was performed collaboratively with plastic surgery (Singhal D) and general surgery
(Critchlow JF) teams at our institution. Operative notes were reviewed to determine intraoperative details,
including the microvascular anastomotic technique.

Intraoperative duplex ultrasonography
An attending radiologist (Tsai LL) performed an intraoperative ultrasound on the back table during the
gastroepiploic omental harvest [Figure 1]. 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] .

Postoperative surveillance
Our standardized process for postoperative surveillance of patients presenting to our Lymphatic Center has
previously been described [18,24] . Briefly, during postoperative surveillance visits, limb measurements were
obtained by a certified lymphedema physical therapist using perometry and L-Dex (Sozo, Impedimed,
Carlsbad, California, USA). Relative volume change (RVC) was calculated using the formula, ,
where A , U are the volume of the affected and unaffected limbs prior to VLNT, and A , U are the volume
1
2
2
1
measurements of the affected and unaffected limbs twelve months post-VLNT . Axial fat-suppressed T2-
[25]
weighted magnetic resonance imaging (MRI) of the affected extremity was obtained at twelve months after
debulking in those with fat-dominant disease, as well as twelve months after VLNT in all patients to assess
for changes in subcutaneous edema and confirm lymph node flap viability. All MRI studies were read and