Lung physiology during ECS resuscitation of DCD donors followed by in situ assessment of lung function.

Extracorporeal cardiopulmonary support (ECS) of donors after cardiac death (DCD) has been shown to improve abdominal organs for transplantation. This study assesses whether pulmonary congestion occurs during ECS with the heart arrested and describes an in vivo method to assess if lungs are suitable for transplantation from DCD donors after ECS resuscitation. Cardiac arrest was induced in 30 kg pigs, followed by 10 min of warm ischemia. Cannulae were placed into the right atrium (RA) and iliac artery, and veno-arterial ECS was initiated for 90 min with lungs inflated, group 1 (n = 5) or deflated, group 2 (n = 3). Left atrial pressures were measured as a marker for pulmonary congestion. After 90 min of ECS, lung function was evaluated. Cannulae were placed into the pulmonary artery (PA) and left ventricle (LV). A second pump was included, and ECS was converted to a bi-ventricular (bi-VAD) system. The RVAD drained from the RA and pumped into the PA, and the LVAD drained the LV and pumped into the iliac. This brought the lungs back into circulation for a 1-hr assessment period. The oxygenator was turned off, and ventilation was restarted. Flows, blood gases, PA and left atrial pressures, and compliance were recorded. In both the groups, LA pressure was <15 mm Hg during ECS. During the lung assessment period, PA flows were 1.4-2.2 L/min. PO2 was >300 mm Hg, with normal PCO2. Extracorporeal cardiopulmonary support resuscitation of DCD donors is feasible and allows for assessment of function before procurement. Extracorporeal cardiopulmonary support does not cause pulmonary congestion, and the lungs retain adequate function for transplantation. Compliance correlated with lung function.

Thirty-day in-parallel artificial lung testing in sheep.

BACKGROUND: Thirty-day testing of the MC3 Biolung (MC3 Inc, Ann Arbor, MI) total artificial lung (TAL) was performed to prepare for future clinical testing. METHODS: TAL inlet and outlet grafts were sewn to the pulmonary artery and left atrium of 8 sheep (35.6 +/- 1.6 kg), and the TAL was attached the next day. Hemodynamic and sheep blood gas data were measured every 1 to 4 hours. TAL blood gases were measured twice daily, and organ function was assessed three times per week. The TAL was replaced if its resistance increased 300% or if the oxygen content difference across the TAL decreased 25% versus baseline. After 30 days, the sheep were euthanized and necropsied. RESULTS: Five sheep survived 30 days. Three sheep were euthanized before 30 days due to bleeding, mechanical graft failure, or gastric distress. Survivors had normal, stable hemodynamics and blood gases. Average device use was 9.5 +/- 2.1 days. TAL oxygen transfer was 108 +/- 9.2 mL/min with 51% +/- 6.3% of cardiac output flowing to the TAL. TAL resistance and flow were 1.3 +/- 0.3 mm Hg x min/L and 2.4 +/- 0.2 L/min at baseline versus 2.6 +/- 0.9 mm Hg x min/L and 2.0 +/- 0.2 L/min for the remaining 30 days. Platelet and white blood cell counts increased 88% and 84% from baseline, respectively, after 10 days and were stable thereafter. Ischemic lesions in the kidney were seen in most sheep at necropsy, but organ function was normal. CONCLUSIONS: Thirty-day respiratory support was feasible with the Biolung, but improvements in biocompatibility and anticoagulation regimen are warranted to reduce the thrombogenicity of the device.

Severe intrarenal fibrosis, infundibular stenosis, renal cysts, and persistent perilobar nephrogenic rests in a patient with Beckwith-Wiedemann syndrome 27 years after diffuse nephroblastomatosis and Wilms tumor: natural progression or a consequence of treatment?

A27-year-old woman presented with back and abdominal pain. She was diagnosed in infancy with Beckwith-Wiedemann syndrome and bilateral multifocal perilobar nephrogenic rests that progressed to diffuse nephroblastomatosis with neoplastic nephroblastomatous rests at 14 months of age and subsequently to a right Wilms tumor at 5 years of age. Computed tomography of the abdomen during the current admission showed multiple obstructed calices. Ureteroscopic inspection of the left kidney revealed severe intrarenal scarring with multiple infundibular stenosis, hydrocalices, and nephrocalcinosis. Renal biopsy showed sclerotic glomeruli with calcification and scarring and persistent subcapsular nodular renal blastema. Electrocautery incision and balloon dilatation provided temporary pain relief. After discharge, the patient has had two or three episodes of recurrent pain associated with new areas of infundibular stenoses and renal cysts. Bilateral nephrectomy and renal transplantation is being considered for management of progressive disease and relief of intractable pain. The potential causes of progressive and severe intrarenal fibrosis, infundibular stenosis and nephrocalcinosis, and renal cysts in this patient may include abnormal renal development secondary to Beckwith-Wiedemann syndrome itself, radiation or chemotherapy damage, or a combination.