Cerebral arterial blood flow and aneurysm surgery

✓ A study of 21 patients was conducted to clarify the autoregulatory capacity in patients subjected to induced hypotension during intracranial surgery for saccular aneurysms. Trimethaphan camsylate (Arfonad) was used for induced hypotension and arterial blood flow was measured with an electromagnetic flow probe on the internal carotid artery or one of its main intracranial branches. In Grade I and II patients the control arterial blood pressure (ABP) ranged from a mean of 90 to 135 mm Hg (average 110 mm Hg), with a lower level of autoregulation (LLAR) from 35 to 85 mm Hg (average 62 mm Hg). Grade III patients had a control ABP of between 105 and 145 mm Hg (average 124 mm Hg) and the LLAR was found to be between 60 and 95 mm Hg (average 76 mm Hg). There was a significant difference between the two groups with regard to both the control ABP and the LLAR. A surprising result obtained from these data was that the average lower autoregulatory range (the difference between control ABP and LLAR) is practically the same in the two groups. A systematic investigation of the upper limit of autoregulation was not possible for ethical reasons. In those few patients in whom spontaneous increase in the ABP made such observations possible, upper limits up to 150 mm Hg with a total autoregulatory capacity of about 75 mm Hg were observed. In some patients, however, lower limits and corresponding “breakthroughs” of cerebral blood flow were seen, demonstrating that the upper limit of autoregulation is markedly influenced by several factors.

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Cerebral arterial blood flow and aneurysm surgery

Journal of Neurosurgery ◽

10.3171/jns.1977.47.6.0810 ◽

1977 ◽

Vol 47 (6) ◽

pp. 810-818 ◽

Cited By ~ 52

Author(s):

Helge Nornes ◽

Per Wikeby

Keyword(s):

Blood Flow ◽

Cerebral Artery ◽

Arterial Blood Flow ◽

Anterior Portion ◽

Flow Measurements ◽

Content Type ◽

Aneurysm Neck ◽

Flow Monitoring ◽

Arterial Blood ◽

Fine Print

✓ Cerebral arterial blood flow was monitored in 22 patients undergoing surgery for intracranial saccular aneurysms. An electromagnetic flow probe was used to record the internal carotid artery (ICA) flow in the neck or intracranially in seven patients. The ICA flow ranged between 100 and 175 ml/min (average 144 ml/min). Intracranial flow measurements with specially designed probes were made in 17 patients. The middle cerebral artery (MCA) showed flow values between 75 and 120 ml/min (average 97 ml/min). Flow figures recorded from the proximal anterior cerebral artery (ACA) were lower (average 65 ml/min), and had a wider range from 30 to 110 ml/min. Test occlusion of the terminal ICA showed a retrograde flow in the proximal ACA to the MCA ranging from 15 to 125 ml/min (average 78 ml/min). This test was used to investigate the collateral potential of the anterior portion of the circle of Willis, which is essential to the decision of whether to undertake trap ligation procedures in this location. Flow monitoring in the parent vessel was also of use in some patients to assess flow conditions after the clipping of the aneurysm neck.

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Effect of separate hemidiaphragm contraction on left phrenic artery flow and O2 consumption

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.1.86 ◽

1990 ◽

Vol 69 (1) ◽

pp. 86-90 ◽

Cited By ~ 7

Author(s):

F. Hu ◽

A. Comtois ◽

E. Shadram ◽

A. Grassino

Keyword(s):

Blood Flow ◽

Nerve Stimulation ◽

Phrenic Nerve ◽

Arterial Blood Flow ◽

O2 Consumption ◽

Phrenic Nerve Stimulation ◽

Diaphragm Pacing ◽

Transdiaphragmatic Pressure ◽

Arterial Blood ◽

Significant Difference

Phrenic arterial blood flow has been shown to increase during bilateral phrenic nerve stimulation (BPNS). However, the role of unilateral phrenic nerve stimulation [left (LPNS) or right (RPNS)] on the blood flow and O2 consumption of the contralateral hemidiaphragm is not known and is explored here. In six anesthetized, mechanically hyperventilated dogs, left phrenic arterial blood flow (Qlpha) was measured (Doppler technique). Supramaximal (10 V, 30 Hz, 0.25-ms duration) LPNS, RPNS, and BPNS at a pacing frequency 15/min and duty cycle of 0.50 were delivered in separate runs. Left hemidiaphragmatic blood samples for gas analyses were obtained by left phrenic venous cannulation. During RPNS, Qlpha and left hemidiaphragmatic O2 consumption (VO2ldi) did not change significantly compared with control. During LPNS and BPNS, there was a significant increase in Qlpha and VO2ldi (P less than 0.01). There was no significant difference in Qlpha and VO2ldi between LPNS and BPNS (P greater than 0.05). We conclude 1) that there is a complete independence of left-right hemidiaphragmatic circulation both at rest and during diaphragm pacing and 2) that during unilateral stimulation transdiaphragmatic pressure is not related to diaphragmatic blood flow.

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The use of indomethacin in the treatment of plateau waves: effects on cerebral perfusion and oxygenation

Journal of Neurosurgery ◽

10.3171/jns.2005.102.3.0455 ◽

2005 ◽

Vol 102 (3) ◽

pp. 455-459 ◽

Cited By ~ 18

Author(s):

Roberto Imberti ◽

Marinella Fuardo ◽

Guido Bellinzona ◽

Michele Pagani ◽

Martin Langer

Keyword(s):

Blood Flow ◽

Cerebral Perfusion ◽

Arterial Blood Flow ◽

Cerebral Tissue ◽

Initial Value ◽

Content Type ◽

Arterial Blood ◽

Plateau Waves ◽

Fine Print ◽

Flow Velocities

Object. Plateau waves are sudden and steep increases in intracranial pressure (ICP) that can develop in patients with cerebral injuries, reduced pressure—volume compensatory reserve, and preserved autoregulation. They are caused by cerebral vasodilation in response to a reduction in cerebral perfusion and are associated with increased cerebral blood volume and reduced cerebral blood flow. The authors evaluated the hypothesis that administration of indomethacin, a potent cerebral arteriolar vasoconstrictor, could interrupt the vicious cycle that occurs during plateau waves, extinguishing these waves and, ultimately, restoring cerebral perfusion and oxygenation. Methods. Plateau waves developed in nine patients, seven with severe traumatic brain injury and two with intraparenchymal hemorrhage. One to four episodes of plateau waves per patient were treated with indomethacin (15–20 mg), which was delivered by an intravenous bolus injection. Each patient's mean arterial blood flow (MABP), ICP, cerebral perfusion pressure (CPP), and cerebral tissue PO2 were continuously monitored and the data obtained were stored in a personal computer. Each patient's jugular venous O2 saturation (SjvO2) and venoarterial difference in PCO2 were evaluated by intermittent blood sampling. During five episodes of plateau waves, middle cerebral artery flow velocities were evaluated by transcranial Doppler ultrasonography. Indomethacin extinguished all plateau waves. On average, the ICP decreased from an initial value of 58.9 ± 11.6 mm Hg to 21.2 ± 8.6 and 25.8 ± 13.7 mm Hg after 5 and 10 minutes, respectively (p < 0.01). The MABP did not change significantly. As a consequence the CPP increased by 98 and 81% after 5 and 10 minutes, respectively (p < 0.01). Five and 10 minutes after indomethacin was administered, SjvO2 increased from an initial value of 50 ± 10.5% to 62 ± 7.6 and 59.9 ± 9.3%, respectively (p < 0.01); the cerebral tissue PO2 increased from an initial value of 13.4 ± 10.6 mm Hg to 23.6 ± 9.58 and 21.9 ± 9.2 mm Hg, respectively (p < 0.05); and the venous—arterial PCO2 decreased significantly. The mean and diastolic flow velocities increased significantly, whereas the pulsatility index decreased from 1.39 ± 0.56 to 1.09 ± 0.4 at 5 minutes and 1.06 ± 0.36 at 10 minutes (p < 0.05). Conclusions. The findings confirm that plateau waves are caused by vasodilation and show that indomethacin, by constricting the cerebral arteries, is effective in extinguishing plateau waves, ultimately restoring cerebral perfusion and oxygenation.

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Intraoperative complications in aneurysm surgery: a prospective national study

Journal of Neurosurgery ◽

10.3171/jns.2002.96.3.0515 ◽

2002 ◽

Vol 96 (3) ◽

pp. 515-522 ◽

Cited By ~ 59

Author(s):

Steen Fridriksson ◽

Hans Säveland ◽

Karl-Erik Jakobsson ◽

Göran Edner ◽

Stefan Zygmunt ◽

...

Keyword(s):

Blood Flow ◽

Intraoperative Complications ◽

Aneurysm Rupture ◽

Arterial Blood Flow ◽

National Study ◽

Aneurysm Surgery ◽

Content Type ◽

Poor Outcome ◽

Arterial Blood ◽

Fine Print

Object. With increasing use of endovascular procedures, the number of aneurysms treated surgically will decline. In this study the authors review complications related to the surgical treatment of aneurysms and address the issue of maintaining quality standards on a national level. Methods. A prospective, nonselected amalgamation of every aneurysm case treated in five of six neurosurgical centers in Sweden during 1 calendar year was undertaken (422 patients; 7.4 persons/100,000 population/year). The treatment protocols at these institutions were very similar. Outcome was assessed using clinical end points. In this series, 84.1% of the patients underwent surgery, and intraoperative complications occurred in 30% of these procedures. Poor outcome from technical complications was seen in 7.9% of the surgically treated patients. Intraoperative aneurysm rupture accounted for 60% and branch sacrifice for 12% of all technical difficulties. Although these complications were significantly related to aneurysm base geometry and the competence of the surgeon, problems still occurred apparently at random and also in the best of hands (17%). The temporary mean occlusion time in the patients who suffered intraoperative aneurysm rupture was twice as long as the temporary arrest of blood flow performed to aid dissection. Conclusions. The results obtained in this series closely reflect the overall management results of this disease and support the conclusion that surgical complications causing a poor outcome can be estimated on a large population-based scale. Intraoperative aneurysm rupture was the most common and most devastating technical complication that occurred. Support was found for a more liberal use of temporary clips early during dissection, regardless of the experience of the surgeon. Temporary regional interruption of arterial blood flow should be a routine method for aneurysm surgery on an everyday basis. A random occurrence of difficult intraoperative problems was clearly shown, and this factor of unpredictability, which is present in any preoperative assessment of risk, strengthens the case for recommending neuroprotection as a routine adjunct to virtually every aneurysm operation, regardless of the surgeon's experience.

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Effect of Selected Manual Therapy Interventions for Mechanical Neck Pain on Vertebral and Internal Carotid Arterial Blood Flow and Cerebral Inflow

Physical Therapy ◽

10.2522/ptj.20120477 ◽

2013 ◽

Vol 93 (11) ◽

pp. 1563-1574 ◽

Cited By ~ 15

Author(s):

Lucy C. Thomas ◽

Darren A. Rivett ◽

Grant Bateman ◽

Peter Stanwell ◽

Christopher R. Levi

Keyword(s):

Blood Flow ◽

Magnetic Resonance ◽

Manual Therapy ◽

Therapeutic Interventions ◽

Arterial Blood Flow ◽

Large Individual ◽

Serious Adverse Events ◽

Arterial Blood ◽

Significant Difference ◽

The Brain

Background Manual therapy of the cervical spine has occasionally been associated with serious adverse events involving compromise of the craniocervical arteries. Ultrasound studies have shown certain neck positions can alter craniocervical arterial blood flow velocities; however, findings are conflicting. Knowledge about the effects of neck position on blood flow may assist clinicians in avoiding potentially hazardous practices. Objective The purpose of this study was to examine the effects of selected manual therapeutic interventions on blood flow in the craniocervical arteries and blood supply to the brain using magnetic resonance angiography (MRA). Design This was an experimental, observational magnetic resonance imaging study. Method Twenty adult participants who were healthy and had a mean age of 33 years were imaged using MRA in the following neck positions: neutral, rotation, rotation/distraction (similar to a Cyriax manipulation), C1–C2 rotation (similar to a Maitland or osteopathic manipulation), and distraction. Results The participants were imaged using 3T MRA. All participants had normal vascular anatomy. Average inflow to the brain in neutral was 6.98 mL/s and was not significantly changed by any of the test positions. There was no significant difference in flow in any of the 4 arteries in any position from neutral, despite large individual variations. Limitations Only individuals who were asymptomatic were investigated, and a short section of the arteries only were imaged. Conclusions Blood flow to the brain does not appear to be compromised by positions commonly used in manual therapy. Positions using end-range neck rotation and distraction do not appear to be more hazardous to cerebral circulation than more segmentally localized techniques.

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Changes in Umbilical Arterial Blood Flow by an Intraamniotic Distilled Water Infusion

Yearbook of Obstetrics Gynecology and Women s Health ◽

10.1016/s1090-798x(08)70024-9 ◽

2007 ◽

Vol 2007 ◽

pp. 30-31

Author(s):

S.H. Ural

Keyword(s):

Blood Flow ◽

Arterial Blood Flow ◽

Distilled Water ◽

Arterial Blood ◽

Water Infusion

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Impact of Pre Transplant Transarterial Chemoembolization on Hepatic Arterial Blood Flow and Outcomes in Liver Transplantation

10.26226/morressier.58eb975dd462b80290b50084 ◽

2017 ◽

Author(s):

Siddharth Jain

Keyword(s):

Liver Transplantation ◽

Blood Flow ◽

Transarterial Chemoembolization ◽

Arterial Blood Flow ◽

Hepatic Arterial Blood Flow ◽

Arterial Blood

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Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

SNE Simulation Notes Europe ◽

10.11128/sne.23.tn.10189 ◽

2013 ◽

Vol 23 (2) ◽

Author(s):

Xenia Descovich ◽

Giuseppe Pontrelli ◽

Sauro Succi ◽

Simone Melchionna ◽

Manfred Bammer

Keyword(s):

Blood Flow ◽

Lattice Boltzmann ◽

Arterial Blood Flow ◽

Arterial Blood ◽

Lattice Boltzmann Simulations ◽

Elastic Walls

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Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord

Children ◽

10.3390/children8050353 ◽

2021 ◽

Vol 8 (5) ◽

pp. 353

Author(s):

Jayasree Nair ◽

Lauren Davidson ◽

Sylvia Gugino ◽

Carmon Koenigsknecht ◽

Justin Helman ◽

...

Keyword(s):

Blood Flow ◽

Perinatal Asphyxia ◽

Arterial Blood Flow ◽

Positive Pressure ◽

Optimal Timing ◽

Delayed Cord Clamping ◽

Arterial Blood ◽

Cord Clamping ◽

Sustained Inflation ◽

Near Term

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.

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