A feedback system to control blood flow in dog lung lobes

1982 ◽  
Vol 53 (6) ◽  
pp. 1650-1652
Author(s):  
R. E. Drake ◽  
D. K. Adcock ◽  
R. L. Scott ◽  
J. C. Gabel

We have developed an electromechanical feedback system to control blood flow to the lower left lung lobe of dogs. Blood flow is measured with an electromagnetic flowmeter. The feedback system compares the blood flow signal to an adjustable reference voltage and causes a motor to turn. The direction of motor rotation depends on the relative magnitude of the flow signal and the reference. The motor pushes the plunger of a syringe that is attached to a balloon in the right pulmonary artery. Inflation of the balloon causes increased blood flow to the lower left lobe. We have used the system to control lobe blood flow in three dogs.

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna Elisabeth Frick ◽  
Michaela Orlitová ◽  
Arno Vanstapel ◽  
Sofie Ordies ◽  
Sandra Claes ◽  
...  

Abstract Background Primary graft dysfunction (PGD) remains a major obstacle after lung transplantation. Ischemia–reperfusion injury is a known contributor to the development of PGD following lung transplantation. We developed a novel approach to assess the impact of increased pulmonary blood flow in a large porcine single-left lung transplantation model. Materials Twelve porcine left lung transplants were divided in two groups (n = 6, in low- (LF) and high-flow (HF) group). Donor lungs were stored for 24 h on ice, followed by left lung transplantation. In the HF group, recipient animals were observed for 6 h after reperfusion with partially clamping right pulmonary artery to achieve a higher flow (target flow 40–60% of total cardiac output) to the transplanted lung compared to the LF group, where the right pulmonary artery was not clamped. Results Survival at 6 h was 100% in both groups. Histological, functional and biological assessment did not significantly differ between both groups during the first 6 h of reperfusion. injury was also present in the right native lung and showed signs compatible with the pathophysiological hallmarks of ischemia–reperfusion injury. Conclusions Partial clamping native pulmonary artery in large animal lung transplantation setting to study the impact of low versus high pulmonary flow on the development of ischemia reperfusion is feasible. In our study, differential blood flow had no effect on IRI. However, our findings might impact future studies with extracorporeal devices and represent a specific intra-operative problem during bilateral sequential single-lung transplantation.


2021 ◽  
Author(s):  
Anna Elisabeth Frick ◽  
Michaela Orlitová ◽  
Arno Vanstapel ◽  
Sofie Ordies ◽  
Sandra Claes ◽  
...  

Abstract Background Primary graft dysfunction (PGD) remains a major obstacle after lung transplantation. Ischemia-reperfusion injury is a known contributor to the development of PGD following lung transplantation. We developed a novel approach to assess the impact of increased pulmonary blood flow in a large porcine single-left lung transplantation model.Materials Twelve porcine left lung transplants were divided in two groups (n = 6, in low (LF) and high flow (HF) group). Donor lungs were stored for 24 hours on ice, followed by left lung transplantation. In the HF group, recipient animals were observed for 6h after reperfusion with partially clamping right pulmonary artery to achieve a higher flow (target flow 40 – 60% of total cardiac output) to the transplanted lung compared to the LF group, where the right pulmonary artery was not clamped.Results Survival at 6 hours was 100% in both groups. Histological, functional and biological assessment did not significantly differ between both groups during the first 6 hours of reperfusion. injury was also present in the right native lung and showed signs compatible with the pathophysiological hallmarks of ischemia-reperfusion injury.Conclusions Partial Clamping native pulmonary artery in large animal lung transplantation setting to study the impact of low versus high pulmonary flow on the development of ischemia reperfusion is feasible. In our study, differential blood flow had no effect on IRI. However, our findings might impact future studies with extra-corporeal devices and represents a specific intra-operative problem during bilateral sequential single lung transplantation.


2014 ◽  
Vol 132 (5) ◽  
pp. 311-313
Author(s):  
Carolina Melendez Valdez ◽  
Stephan Philip Leonhardt Altmayer ◽  
Adyr Eduardo Virmond Faria ◽  
Aline Weiss ◽  
Jorge Alberto Bianchi Telles ◽  
...  

CONTEXT: Intrathoracic cystic lesions have been diagnosed in a wide variety of age groups, and the increasing use of prenatal imaging studies has allowed detection of these defects even in utero.CASE REPORT: A 17-year-old pregnant woman in her second gestation, at 23 weeks of pregnancy, presented an ultrasound with evidence of a cystic anechoic image in the fet al left hemithorax. A morphological ultrasound examination performed at the hospital found that this cystic image measured 3.7 cm x 2.1 cm x 1.6 cm. Polyhydramnios was also present. At this time, the hypothesis of cystic adenomatoid malformation was raised. Fet al echocardiography showed only a dextroposed heart. Fet al magnetic resonance imaging produced an image compatible with a left diaphragmatic hernia containing the stomach and at least the first and second portions of the duodenum, left lobe of the liver, spleen, small intestine segments and portions of the colon. The stomach was greatly distended and the heart was shifted to the right. There was severe volume reduction of the left lung. Fet al karyotyping showed the chromosomal constitution of 47,XXY, compatible with Klinefelter syndrome. In our review of the literature, we found only one case of association between Klinefelter syndrome and diaphragmatic hernia.CONCLUSIONS: We believe that the association observed in this case was merely coincidental, since both conditions are relatively common. The chance of both events occurring simultaneously is estimated to be 1 in 1.5 million births.


1992 ◽  
Vol 73 (4) ◽  
pp. 1291-1296 ◽  
Author(s):  
L. E. Olson ◽  
R. L. Wardle

We examined whether wedging a catheter (0.5 cm OD) into a subsegmental airway in dog (n = 6) or pig lungs (n = 5) and increasing pressure in the distal lung segment affected pulmonary blood flow. Dogs and pigs were anesthetized and studied in the prone position. Pulmonary blood flow was measured by injecting radiolabeled microspheres (15 microns diam) into the right atrium when airway pressure (Pao) was 0 cmH2O and pressure in the segment distal to the wedged catheter (Ps) was 0, 5, or 15 cmH2O and when Pao = Ps = 15 cmH2O. The lungs were excised, air-dried, and sectioned. Blood flow per gram dry weight normalized to cardiac output to the right or left lung, as appropriate, was calculated for the test segment, a control segment in the opposite lung corresponding anatomically to the test segment, the remainder of the lung containing the test segment (test lung), and the remainder of the lung containing the control segment (control lung). The presence of the catheter reduced blood flow in the test segment compared with that in the control segment and in the test lung. Blood flow was not affected by increasing pressure in the test segment. We conclude that, in studies designed to measure collateral ventilation in dog lungs, the presence of the wedged catheter is likely to have a greater effect on blood flow than the increase in pressure associated with measuring collateral airway resistance.


1995 ◽  
Vol 117 (2) ◽  
pp. 237-241
Author(s):  
H. Katayama ◽  
G. W. Henry ◽  
C. L. Lucas ◽  
B. Ha ◽  
J. I. Ferreiro ◽  
...  

We studied the detailed profiles of blood flow in the right and left pulmonary arteries using 20 MHz pulsed Doppler ultrasound equipment in a lamb model. Fourteen lambs aged four to six weeks were selected. In six lambs, monocrotaline pyrrole was injected parenterally to create pulmonary hypertension (PH group). Eight other lambs served as unaltered controls (control group). The blood flow velocities were sampled in 1mm increments along the anterior—posterior axis of the branch arteries. The maximum velocity of the forward flow in the left pulmonary artery was higher than that in the right pulmonary artery in the control group (71.7 ± 15.9cm/s vs 60.2 ± 13.5; p < 0.05). The fastest backward flow was located at the posterior position of the vessel in the right pulmonary artery in the control group. No significant bias in location was shown in the left pulmonary artery. Using indices of P90, acceleration time, P90*AcT, the velocity waveforms in the PH group were compared with those in the control group. In the left pulmonary artery, every index in the control group showed a significantly greater value that in the PH group. On the other hand, no significant differences were found between either group in the right pulmonary artery.


2006 ◽  
Vol 101 (5) ◽  
pp. 1451-1465 ◽  
Author(s):  
Deokiee Chon ◽  
Kenneth C. Beck ◽  
Ranae L. Larsen ◽  
Hidenori Shikata ◽  
Eric A. Hoffman

ECG-triggered computed tomography (CT) was used during passage of iodinated contrast to determine regional pulmonary blood flow (PBF) in anesthetized prone/supine dogs. PBF was evaluated as a function of height within the lung (supine and prone) as a function of various normalization methods: raw unit volume data (PBFraw) or PBF normalized to regional fraction air (PBFair), fractional non-air (PBFgm), or relative number of alveoli (PBFalv). The coefficient of variation of PBFraw, PBFair, PBFalv, and PBFgm ranged between 30 and 50% in both lungs and both body postures. The position of maximal flow along the height of the lung (MFP) was calculated for PBFraw, PBFair, PBFalv, and PBFgm. Only PBFgm showed a significantly different MFP height supine vs. prone (whole lung: 2.60 ± 1.08 cm supine vs. 5.08 ± 1.61 cm prone, P < 0.01). Mean slopes (ml/min/gm water content/cm) of PBFgm were steeper supine vs. prone in the right (RL) but not left lung (LL) (RL: −0.65 ± 0.29 supine vs. −0.26 ± 0.25 prone, P < 0.02; LL: −0.47 ± 0.21 supine vs. −0.32 ± 0.26 prone, P > 0.10). Mean slopes of PBFgm vs. vertical lung height were not different prone vs. supine above this vertical height of MFP (VMFP), but PBFgm slopes were steeper in the supine position below the VMFP in the RL. We conclude that PBFgm distribution was posture dependent in RL but not LL. Support of the heart may play a role. We demonstrate that normalization factors can lead to differing attributions of gravitational effects on PBF heterogeneity.


1998 ◽  
Vol 84 (6) ◽  
pp. 2010-2019 ◽  
Author(s):  
Christopher M. Mann ◽  
Karen B. Domino ◽  
Sten M. Walther ◽  
Robb W. Glenny ◽  
Nayak L. Polissar ◽  
...  

We used fluorescent-labeled microspheres in pentobarbital-anesthetized dogs to study the effects of unilateral alveolar hypoxia on the pulmonary blood flow distribution. The left lung was ventilated with inspired O2 fraction of 1.0, 0.09, or 0.03 in random order; the right lung was ventilated with inspired O2 fraction of 1.0. The lungs were removed, cleared of blood, dried at total lung capacity, then cubed to obtain ∼1,500 small pieces of lung (∼1.7 cm3). The coefficient of variation of flow increased ( P < 0.001) in the hypoxic lung but was unchanged in the hyperoxic lung. Most (70–80%) variance in flow in the hyperoxic lung was attributable to structure, in contrast to only 30–40% of the variance in flow in the hypoxic lung ( P < 0.001). When adjusted for the change in total flow to each lung, 90–95% of the variance in the hyperoxic lung was attributable to structure compared with 70–80% in the hypoxic lung ( P < 0.001). The hilar-to-peripheral gradient, adjusted for change in total flow, decreased in the hypoxic lung ( P = 0.005) but did not change in the hyperoxic lung. We conclude that hypoxic vasoconstriction alters the regional distribution of flow in the hypoxic, but not in the hyperoxic, lung.


2006 ◽  
Vol 16 (1) ◽  
pp. 89-91 ◽  
Author(s):  
Hamish M. Munro ◽  
Andrea M. C. Sorbello ◽  
David G. Nykanen

A baby presented at term with respiratory distress was managed with extracorporeal membrane oxygenation. Bronchoscopy revealed tracheal hypoplasia, complete tracheal rings, and agenesis of the right main bronchus. Echocardiography showed a left pulmonary arterial sling arising from the proximal part of the right pulmonary artery. Cardiac catheterization demonstrated abnormal pulmonary vasculature in the left lung which would have prevented survival, even after surgical repair. Diagnostic catheterization was important in delineating the anatomy, and aided in the decision not to proceed with surgical repair.


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