ABSTRACT
Heart-lung transplant (HLT) is a widely accepted modality for certain patients with advanced and refractory cardiopulmonary disease. Some of these patients are critically ill on the transplant waiting list, and venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be used as a bridge to transplantation. Although the experience with ECMO as a bridge to lung transplant is promising, there is limited evidence to use ECMO as a bridge to HLT. Femoral cannulation remains a concern for ambulation given the risk of bleeding and cannula complications despite studies reporting its safety. We present a case of a 56-year-old male with interstitial lung disease and severe secondary pulmonary hypertension, who was successfully bridged to HLT with ambulatory femoral VA-ECMO.
Subject(s)
Extracorporeal Membrane Oxygenation/methods , Heart-Lung Transplantation , Hypertension, Pulmonary/therapy , Lung Diseases, Interstitial/therapy , Lung Transplantation , Femoral Artery , Humans , Hypertension, Pulmonary/etiology , Lung Diseases, Interstitial/complications , Male , Middle Aged , Severity of Illness Index , Treatment Outcome , Waiting ListsABSTRACT
Quality control of microdevices adds significant costs, in time and money, to any fabrication process. A simple, rapid quantitative method for the post-fabrication characterization of microchannel architecture using the measurement of flow with volumes relevant to microfluidics is presented. By measuring the mass of a dye solution passed through the device, it circumvents traditional gravimetric and interface-tracking methods that suffer from variable evaporation rates and the increased error associated with smaller volumes. The multiplexed fluidic resistance (MFR) measurement method measures flow via stable visible-wavelength dyes, a standard spectrophotometer and common laboratory glassware. Individual dyes are used as molecular markers of flow for individual channels, and in channel architectures where multiple channels terminate at a common reservoir, spectral deconvolution reveals the individual flow contributions. On-chip, this method was found to maintain accurate flow measurement at lower flow rates than the gravimetric approach. Multiple dyes are shown to allow for independent measurement of multiple flows on the same device simultaneously. We demonstrate that this technique is applicable for measuring the fluidic resistance, which is dependent on channel dimensions, in four fluidically connected channels simultaneously, ultimately determining that one chip was partially collapsed and, therefore, unusable for its intended purpose. This method is thus shown to be widely useful in troubleshooting microfluidic flow characteristics.