The novel Mechanical Ventilator Milano for the COVID-19 pandemic.

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

[Delayed presentation of left-side congenital diaphragmatic hernia. Personal experience]. / Ernia diaframmatica congenita sinistra a presentazione tardiva. Esperienza personale.

The Authors report their experience on four patients affected with left-sided congenital diaphragmatic hernia presented in the post-natal period. They describe the symptoms, diagnosis and surgical approach and discuss the prompt and normal response of the respiratory function to the operation.

Segmental duct-obstructed pancreas grafts versus pancreaticoduodenal grafts with enteric diversion.

Between January 1985 and September 1987, we performed a prospective comparative study between segmental-pancreas transplantation with duct obstruction by neoprene (n = 17) and pancreaticoduodenal transplantation with enteric diversion to a Roux-en-Y intestinal loop (n = 14). All recipients had insulin-dependent diabetes. The immunosuppressive protocol consisted of low doses of the steroids cyclosporin A and azathioprine. Mean follow-up was 16.5 mo for the enteric-diversion group and 13.5 mo for duct-obstructed groups. Two-year patient and pancreas- and kidney-graft actuarial survival rates were 92.9, 75.5, and 74.2%, respectively, in the former group and 92.3, 58.4, and 63.7%, respectively, in the latter group (NS). Five whole-organ grafts were lost (3 vascular thromboses, 1 pancreatitis, 1 rejection), and four segmental grafts were lost (2 vascular thromboses, 1 bleeding, 1 patient's death with functional graft). More surgical complications occurred in the recipients of whole-organ grafts and were often related to the intestinal anastomosis. A satisfactory blood glucose control was observed at 3 mo and 1 yr in both groups. Provocative tests showed higher and prompter insulin secretion in patients with whole-organ grafts. In patients with segmental grafts, the response was lower and delayed with a general tendency to impaired glucose tolerance. A marked hyperinsulinemia after meals was observed in whole-organ graft recipients. Slight nocturnal hyperinsulinemia was observed in both groups. At 1 yr, glycosylated hemoglobin was normal in both groups. The absence of a significant difference between the two groups, in terms of survival and graft function, and the lower surgical complication rate seen with segmental grafts have made us return to neoprene-injected segmental grafts.

Impact of immunosuppression on improvement of results in clinical pancreas transplantation.

Since November 1975, 103 pancreas transplantations have been performed in 97 insulin-dependent diabetic patients. Pancreas and kidney were grafted simultaneously in 84 patients (plus 1 double retransplantation). Eighty-nine pancreas grafts were prepared by duct obstruction with neoprene, and 14 were pancreaticoduodenal grafts with enteric diversion in a Roux-en-Y loop. Five immunosuppressive protocols were subsequently used. With the latest protocols, patient and pancreas survival improved to 93 and 72% at 1 yr, respectively. The improvement in graft survival appeared to be particularly related to the reduction of the number of pancreas grafts lost in rejection. The patients treated with the last protocols, including cyclosporin A (CsA) and only low doses of steroids, showed a better glucose tolerance after provocative tests. Pancreas-graft function did not appear to be influenced by CsA treatment.

Kidney-graft survival in simultaneous kidney-pancreas transplantation.

Patient and kidney survival rates were compared between 69 diabetic patients undergoing simultaneous kidney-pancreas transplantation (group 1) and 723 nondiabetic patients undergoing kidney transplantation (group 2). The patients were treated with different immunosuppressive regimens over the years: steroids plus antilymphocyte globulin (ALG) plus azathioprine (Aza); cyclosporin A (CsA) plus ALG; steroids plus ALG plus Aza, replacing Aza 1 mo posttransplantation; or low doses of steroids plus CsA plus Aza. One-year kidney survival rates with the different regimens were 50, 42, 54, and 76%, respectively, in group 1 and 71, 74, 78, and 84%, respectively, in group 2. Patient survival was 60, 57, 71, and 86%, respectively, in group 1 and 93, 95, 94, and 96%, respectively, in group 2. Differences between the two groups were statistically significant for the first three protocols but not for the one used in this study. In group 1, 38 patients (55%) had a functioning kidney graft, whereas 15 (21%) lost their kidney to rejection. Between these two patient categories, there was no significant difference in age, sex, duration of diabetes, time on dialysis, blood transfusion number, HLA immunization, or HLA matching. Thus, since 1984, kidney-graft survival has not been inferior in diabetic patients. This improvement is mainly due to a decreased mortality related to better patient preparation and improvement in immunosuppression.

Clinical experience in pancreas transplantation in Lyon: long-term survival of duct injected pancreatic grafts.

Ninety-seven pancreatic grafts in 92 insulin-dependent diabetic patients were performed during the last 11 years. Eighty-three of these grafts were carried out after neoprene duct injection, the other patients underwent pancreato-duodenal transplantation. In 80 cases, a double pancreas and kidney graft was performed. Five different immunosuppressive protocols were subsequently applied. Actuarial survival of patients and pancreata was 75.1% and 47%, after one year and 54.6% and 22.1%, respectively, 4 years after transplantation. Slightly better results were observed in double pancreas and kidney transplantation. The survival of both patients and pancreas improved when the most recent immunosuppressive protocols including cyclosporin A and only small doses of steroids were applied. The main causes of loss of the pancreatic graft were rejection, vascular thrombosis and death of the patient with functioning organ. Metabolic studies showed good insulin secretion with normal or impaired glucose tolerance as well as good short and half-term glycemic control. Whole pancreas grafts with enteric diversion yielded prompter and higher insulin secretion but the incidence of surgical complications was increased. In comparison to the data recorded at 6 months after pancreas transplantation, 5 patients of our series with still functioning organ showed an equally satisfactory and unchanged glycemic control after more than 4 years from surgery. In these patients, the previously high insulinemic values decreased to normal levels. However, 3 of these patients showed a decrease in post-prandial peaks as confirmed also by OGTT. However, mean blood glucose level was not altered. In our series the suppression of exocrine pancreatic secretion by neoprene duct injection did not appear to represent a relevant cause of decrease in endocrine function. The results obtained do not yet allow us to draw definite conclusions as to the efficacy of pancreas transplantation in the treatment of degenerative complications in diabetic patients.

Modifications of the vein wall after microsurgical end-to-side artero-venous anastomosis.

The repercussions on the venous wall of the creation of 20 artero-venous anastomoses (AVA) between the femoral artery and vein of the rat have been evaluated. The rats were killed 7, 15, 30, and 90 days after AVA, and AVAs were examined by optical microscopy and by scanning electronic microscopy. Deposits of whitish material that nearly completely occluded the venous lumen were seen, especially in the group studied longer than 90 days. These venous wall lesions, which resemble arteriosclerotic lesions, must be attributed to the new hemodynamic situation created by the AVA. The implications of such findings for the long-term validity of venous graft in vascular microsurgery and the long-term patency of the AVA in hemodialyzed children are discussed.