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Serial Systemic Injections of Endotoxin (LPS) Elicit Neuroprotective Spinal Cord Microglia through IL-1-Dependent Cross Talk with Endothelial Cells. J Neurosci 2020; 40:9103-9120. [PMID: 33051350 DOI: 10.1523/jneurosci.0131-20.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 09/13/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Microglia are dynamic immunosurveillance cells in the CNS. Whether microglia are protective or pathologic is context dependent; the outcome varies as a function of time relative to the stimulus, activation state of neighboring cells in the microenvironment or within progression of a particular disease. Although brain microglia can be "primed" using bacterial lipopolysaccharide (LPS)/endotoxin, it is unknown whether LPS delivered systemically can also induce neuroprotective microglia in the spinal cord. Here, we show that serial systemic injections of LPS (1 mg/kg, i.p., daily) for 4 consecutive days (LPSx4) consistently elicit a reactive spinal cord microglia response marked by dramatic morphologic changes, increased production of IL-1, and enhanced proliferation without triggering leukocyte recruitment or overt neuropathology. Following LPSx4, reactive microglia frequently contact spinal cord endothelial cells. Targeted ablation or selective expression of IL-1 and IL-1 receptor (IL-1R) in either microglia or endothelia reveal that IL-1-dependent signaling between these cells mediates microglia activation. Using a mouse model of ischemic spinal cord injury in male and female mice, we show that preoperative LPSx4 provides complete protection from ischemia-induced neuron loss and hindlimb paralysis. Neuroprotection is partly reversed by either pharmacological elimination of microglia or selective removal of IL-1R in microglia or endothelia. These data indicate that spinal cord microglia are amenable to therapeutic reprogramming via systemic manipulation and that this potential can be harnessed to protect the spinal cord from injury.SIGNIFICANCE STATEMENT Data in this report indicate that a neuroprotective spinal cord microglia response can be triggered by daily systemic injections of LPS over a period of 4 d (LPSx4). The LPSx4 regimen induces morphologic transformation and enhances proliferation of spinal cord microglia without causing neuropathology. Using advanced transgenic mouse technology, we show that IL-1-dependent microglia-endothelia cross talk is necessary for eliciting this spinal cord microglia phenotype and also for conferring optimal protection to spinal motor neurons from ischemic spinal cord injury (ISCI). Collectively, these novel data show that it is possible to consistently elicit spinal cord microglia via systemic delivery of inflammogens to achieve a therapeutically effective neuroprotective response against ISCI.
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Abstract
The conduct of partial left heart bypass or partial car diopulmonary bypass (CPB) during surgery involving the descending thoracic aorta or thoracoabdominal aorta is one of the most unappreciated and misunder stood extracorporeal circulation procedures in cardio vascular surgery. It is different from conventional CPB, and although some uninitiated practitioners consider it simpler, it is in fact more complicated than conven tional CPB and involves different concepts. It requires expertise and skill in regulating the flow, pressure, and oxygenation of blood going to both the proximal and distal parts of the body and management of the special bypass or shunt procedures used, specialized monitor ing, and knowledge about the protection and preserva tion of organs both proximal and distal to the aortic clamping. It demands exquisite communication and un derstanding of the unique problems faced by the sur geon, anesthesiologist, and perfusionist.
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Affiliation(s)
- Eugene A. Hessel
- Department of Anesthesiology, College of Medicine, Chandler Medical Center, University of Kentucky, Louisville, KY
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Juvonen T, Biancari F, Rimpiläinen J, Satta J, Rainio P, Kiviluoma K. Strategies for Spinal Cord Protection during Descending Thoracic and Thoracoabdominal Aortic Surgery: Up-to-date Experimental and Clinical Results - A review. SCAND CARDIOVASC J 2009. [DOI: 10.1080/cdv.36.3.136.160] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Barkhordarian S, Dardik A. Preoperative assessment and management to prevent complications during high-risk vascular surgery. Crit Care Med 2004; 32:S174-85. [PMID: 15064676 DOI: 10.1097/01.ccm.0000115625.30405.12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Most patients requiring vascular surgical reconstruction are at high risk for major morbidity and mortality, with certain vascular procedures at particularly high risk for complications. Although numerous comorbid conditions are precisely the risk factors that determine outcome, we review particular factors for each surgery that may be optimized to alter outcome and minimize postoperative complications. DESIGN Literature review. RESULTS Certain aspects of care are common to all vascular surgery procedures, including thoracoabdominal aortic aneurysm repair, pararenal and ruptured abdominal aortic aneurysm repair, mesenteric and renal revascularization, and carotid endarterectomy. Some factors that are important include careful preoperative assessment and optimization of cardiac, pulmonary, and renal function and volume status. In addition, the use of experienced teams during and after the procedure, as well as clear and continuous communication between all surgical team members, may improve outcome. Particular attention to procedural details is also crucial to achieving excellent results. CONCLUSIONS Patients needing vascular surgery often possess management challenges that increase the risk of perioperative complications. Meticulous attention to details during all phases of care, including preoperative optimization as well as intraoperative procedural conduct and communication, helps achieve optimal results and thus minimize the risk of complications.
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Affiliation(s)
- Siamak Barkhordarian
- Yale University School of Medicine, Section of Vascular Surgery, New Haven, CT, USA
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Estrera AL, Huynh TTT, Porat EE, Miller CC, Smith JJ, Safi HJ. Is acute type A aortic dissection a true surgical emergency? Semin Vasc Surg 2002; 15:75-82. [PMID: 12060896 DOI: 10.1053/svas.2002.33093] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Untreated acute aortic dissection involving the ascending aorta (type A) is associated with a high early mortality owing to rupture. Despite advancements in surgical technique and critical care, early mortality remains high. Operative mortality may be related to the technical challenges associated with intervening on the acutely dissected aorta as well as the multiorgan insult it induces. In this article, we review our approach to acute type A aortic dissection with regard to diagnosis, initial medical management, surgical repair, and timing of repair.
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Affiliation(s)
- Anthony L Estrera
- Department of Cardiothoracic and Vascular Surgery, The University of Texas at Houston Medical School and Memorial Hermann Hospital, 77030, USA
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Hellberg A, Christiansson L, Tulga Ulus A, Bergqvist D, Wiklund L, Karacagil S. A prolonged spinal cord ischaemia model in pigs. Passive shunting offers stable central haemodynamics during aortic occlusion. Eur J Vasc Endovasc Surg 2000; 19:318-23. [PMID: 10753699 DOI: 10.1053/ejvs.1999.1027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES to evaluate the effect of a modified aortic shunt on central haemodynamic variables during experimental thoracic aortic occlusion in a prolonged spinal cord ischaemia model. MATERIAL AND METHODS central haemodynamic variables were evaluated during aortic cross-clamping. In the shunt group (n=11), after the placement of proximal and distal aortic clamps, distal aortic perfusion was restored through an aortoiliac shunt via the left subclavian artery. In the no-shunt group (n=11), spinal cord ischaemia was achieved with only proximal aortic cross-clamping. The clamping time was 60 minutes in the shunt group and 30 minutes in the no-shunt group. RESULTS in the no-shunt group, all animals needed inotropic support, vasodilators and buffers during the experiment. None of these drugs were needed in the shunt group. In the no-shunt group, cross-clamping caused a significant increase in mean arterial pressure and heart rate compared to baseline values. These variables were stable in the shunt group during aortic occlusion. In the reperfusion period cardiac output, heart rate and arterial pCO(2)were significantly higher in the no-shunt than in the shunt group. CONCLUSION the present experimental spinal cord ischaemia model, using double aortic cross-clamping with shunt, offers improved central haemodynamics. This enables the study of prolonged selective spinal cord ischaemia without interaction from vasoactive drugs or systemic reperfusion.
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Affiliation(s)
- A Hellberg
- Department of Surgery, University Hospital, Uppsala, Sweden
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de Haan P, Kalkman CJ, Meylaerts SA, Lips J, Jacobs MJ. Development of spinal cord ischemia after clamping of noncritical segmental arteries in the pig. Ann Thorac Surg 1999; 68:1278-84. [PMID: 10543493 DOI: 10.1016/s0003-4975(99)00727-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Blood flow to the thoracolumbar spinal cord is thought to be critically dependent on the arteria radicularis magna. We investigated whether spinal cord blood supply becomes dependent on other, noncritical, segmental arteries if spinal cord perfusion pressure (SCPP) is decreased. The SCPP is equal to the mean arterial pressure (MAP) minus the cerebrospinal fluid (CSF) pressure (SCCP = MAP - CSF). METHODS The thoracoabdominal aorta was exposed in 10 pigs. Functional integrity of spinal cord motor pathways was assessed with myogenic motor-evoked potentials after transcranial electrical stimulation (tc-MEPs). Using this technique, a group of segmental arteries not critical for spinal cord blood supply was identified. Before, during, and after clamping of the noncritical segmental arteries, spinal cord ischemia was produced by decreasing SCPP by means of increasing CSF pressure, and the SCPP threshold at which tc-MEPs showed evidence of spinal cord ischemia was determined. Ischemic SCPP thresholds, obtained during and after clamping of the noncritical segmental arteries, were compared with the ischemic threshold obtained before clamping (control value). RESULTS Before noncritical segmental arteries were clamped, ischemic tc-MEP changes occurred when the SCPP was below 15 +/- 5 (SD) mm Hg. With a total of 9 +/- 3 (SD) segmental arteries clamped, the ischemic SCPP threshold was 48 +/- 14 mm Hg (p < 0.01). After the release of all clamps, ischemia occurred at a SCPP of 15 +/- 5 (SD) mm Hg. CONCLUSIONS In this porcine experiment, clamping of originally noncritical segmental arteries significantly reduced the tolerance of the spinal cord to a decrease in SCPP.
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Affiliation(s)
- P de Haan
- Department of Anesthesiology, Academic Hospital, University of Amsterdam, Academic Medical Center, The Netherlands.
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Greenberg R, Risher W. Clinical decision making and operative approaches to thoracic aortic aneurysms. Surg Clin North Am 1998; 78:805-26. [PMID: 9891578 DOI: 10.1016/s0039-6109(05)70352-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The care of the patient with thoracic aneurysms is quite complicated. The decision to treat an aneurysm must be based on the risk of rupture and the patient's life expectancy. The preoperative evaluation must include detailed imaging to allow proper preoperative planning. This is especially important to determine the need for hypothermic circulatory arrest or the potential to treat a descending aneurysm with an endovascular approach. Thorough preoperative preparation and intraoperative care are as important as surgical decision making and meticulous technique. Although significant advances have been made in operative approaches, cerebral and myocardial preservation, and postoperative care, the management of complicated aneurysms of the thoracic aorta is frequently a humbling experience.
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Affiliation(s)
- R Greenberg
- Department of Surgery, University of Rochester-Strong Memorial Hospital, New York, USA
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Cambria RP, Giglia JS. Prevention of spinal cord ischaemic complications after thoracoabdominal aortic surgery. Eur J Vasc Endovasc Surg 1998; 15:96-109. [PMID: 9551047 DOI: 10.1016/s1078-5884(98)80129-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since the publication of prior reviews on this topic, substantial clinical experience with a variety of operative strategies to prevent ischaemic cord complications has been reported. The available data on angiographic localisation of critical intercostal vessels, and, in particular, the evoked potential response to cross-clamping in patients indicates that risk of paraplegia varies considerably even among patients with equivalent TAA extent. Factors such as individual development of the ASA, patent critical intercostals, and the particulars of collateral circulation when intercostal aortic ostia are already occluded likely account for this variability. Information available from SSEP monitoring relative to the dynamic course of cord ischaemia with cross-clamping, and the parallel, if not, frustrating experience with angiographic localisation and intercostal vessel reconstruction indicates that a narrow temporal threshold of cord ischaemia with clamping is present in many patients. This reinforces the importance of both expeditious clamp intervals, critical intercostal re-anastomoses, and the desirability of neuroprotective manoeuvres during cross-clamp induced cord ischemia. As suggested in compelling experimental work our contemporary clinical experience, and predicted by prior reviewers, regional cord hypothermia provides significant promise for limiting or eliminating, in particular, immediate perioperative deficits. Avoidance of postoperative hypotension, spinal cord oedema, and preservation of critical intercostal vessels are additional strategies necessary to impact the development of delayed deficits favourably.
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Affiliation(s)
- R P Cambria
- Department of Surgery, Massachusetts General Hospital, Boston 02114, USA
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Abstract
BACKGROUND Although rare, paralysis secondary to spinal cord ischaemia after aortic aneurysm surgery is a devastating complication. Many papers have been published on this topic but without a clear consensus on the best way of minimizing the problem. Recent articles have included advanced pharmacological approaches and the literature has been reviewed in light of these. METHODS Relevant papers were identified by an extensive text word search of the Medline database and a review of quoted articles. RESULTS Spinal cord complications are commoner after the repair of Crawford type II aneurysms than less extensive aneurysms. The presence of dissection, rupture and prolonged clamp times are associated with an increased incidence. About a quarter of all cord problems develop over 24 h after surgery and this may be due to a reperfusion type injury, although the exact mechanisms are by no means clear. CONCLUSION A combination of rapid surgery, left heart bypass for the repair of more extensive aneurysms, free spinal drainage and the avoidance of postoperative hypoxia and hypotension help to minimize spinal cord ischaemia. No pharmacological agent has yet been shown conclusively to improve outcome in the clinical setting.
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Affiliation(s)
- P Lintott
- Academic Surgical Unit, Imperial College School of Medicine at St Mary's, St Mary's Hospital, London, UK
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O'Connor CJ, Rothenberg DM. Anesthetic considerations for descending thoracic aortic surgery: part II. J Cardiothorac Vasc Anesth 1995; 9:734-47. [PMID: 8664471 DOI: 10.1016/s1053-0770(05)80241-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- C J O'Connor
- Department of Anesthesiology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA
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Simpson JI, Eide TR, Schiff GA, Clagnaz JF, Zisbrod Z, Newman SB, Hossain I. Isoflurane versus sodium nitroprusside for the control of proximal hypertension during thoracic aortic cross-clamping: effects on spinal cord ischemia. J Cardiothorac Vasc Anesth 1995; 9:491-6. [PMID: 8547547 DOI: 10.1016/s1053-0770(05)80129-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE This study was designed to compare the effects of isoflurane and nitroprusside on spinal cord ischemia when they are used to control proximal hypertension during thoracic aortic cross-clamping (TACC). DESIGN Prospective, randomized, blinded experimental study. SETTING Laboratory and animal research facility. PARTICIPANTS Adult mongrel dogs. INTERVENTIONS Two groups of eight dogs had TACC for 45 minutes. Proximal aortic, distal aortic, and cerebrospinal pressure was calculated as the distal mean pressure minus the CSF pressure. Group 1 received nitroprusside and group 2 received isoflurane to control proximal hypertension during cross-clamping. The dogs were neurologically evaluated 24 and 48 hours later by an observer blinded as to the study group. Spinal cord segments were obtained for histopathologic examination. MEASUREMENTS AND MAIN RESULTS Distal perfusion pressure and spinal cord perfusion pressure were significantly higher in the isoflurane group (p < .005). At 24 hours, seven of eight dogs in group 1 had severe neurologic injury (ie, paraplegia), with the eight having mild neurologic injury. This is in contrast to group 2, where 6 of 8 dogs had either minimal or no injury, one had mild injury, and one had severe injury. Similar results were observed at 48 hours (p < .005). CONCLUSIONS Isoflurane, when used to control proximal hypertension during TACC, produces a higher spinal cord perfusion pressure and is associated with a lower incidence of neurologic injury than nitroprusside in this canine model.
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Affiliation(s)
- J I Simpson
- Department of Anesthesiology, Long Island Jewish Medical Center, New Hyde Park, NY 11042, USA
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Acher CW, Wynn MM, Hoch JR, Popic P, Archibald J, Turnipseed WD. Combined use of cerebral spinal fluid drainage and naloxone reduces the risk of paraplegia in thoracoabdominal aneurysm repair. J Vasc Surg 1994; 19:236-46; discussion 247-8. [PMID: 8114185 DOI: 10.1016/s0741-5214(94)70099-0] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE This report summarizes our experience with the use of cerebral spinal fluid drainage (CSFD) and naloxone for prevention of postoperative neurologic deficit (paraplegia or paraparesis). METHODS We reviewed 110 consecutive patients with 86 thoracoabdominal aneurysms and 24 thoracic aneurysms. The status of 47 patients (43%) was acute (rupture or dissection), and the status of 52 (47%) was Crawford type I or II. None of the patients had intercostal artery reimplantation. There were two patient groups for analysis of neurologic deficit risk. Group A (61 patients) received naloxone and CSFD, and group B (49 patients) did not. RESULTS One deficit occurred in group A and 11 deficits occurred in group B (p = 0.001). By multiple logistic regression analysis, the variables acute status, Crawford type II, or group B classification were significant factors for deficit risk. Use of the same logistic regression analysis on the subgroup of 47 patients with acute aneurysms and 33 patients with Crawford type 2 aneurysms confirmed the protective effect of combined CSFD and naloxone (group A) and that clinical presentation and extent of aorta replaced are the primary risk factors for development of deficit. To test this conclusion we developed a highly predictive model (correlation coefficient 0.997 with 16 series of thoracoabdominal aneurysms) for neurologic deficit. We applied our data to this model. Group B had the predicted number of deficits, and group A had substantially fewer deficits than predicted. CONCLUSIONS We conclude that the combined use of CSFD and naloxone offers significant protection from neurologic deficits in patients undergoing thoracoabdominal and thoracic aortic replacement.
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Affiliation(s)
- C W Acher
- University of Wisconsin Hospital, Madison
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Cernaianu AC, Olah A, Cilley JH, Gaprindashvili T, Gallucci JG, DelRossi AJ. Effect of sodium nitroprusside on paraplegia during cross-clamping of the thoracic aorta. Ann Thorac Surg 1993; 56:1035-7; discussion 1038. [PMID: 8239796 DOI: 10.1016/0003-4975(95)90009-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Sodium nitroprusside (SNP) is usually used to control excessive proximal pressure after aortic cross-clamping. To assess the effect of SNP on circulatory dynamics, somatosensory evoked potentials, and neurologic outcome, 10 adult mongrel dogs that underwent 45 minutes of cross-clamping of the thoracic aorta were randomly assigned to receive either 50 mg/kg of SNP or no treatment for excessive proximal hypertension. There was a statistically significant difference noted between the SNP-treated animals and the control animals in terms of the proximal mean arterial pressures (112 +/- 13 versus 142.2 +/- 15 mm Hg, respectively; p < 0.05) and the mean distal arterial pressures (15 +/- 3 mm Hg versus 23 +/- 1 mm Hg; p = 0.04). However, the electrical activity of the spinal cord, as indicated by the somatosensory evoked potentials, returned significantly faster in the nontreated group than in the SNP-treated group (15 +/- 9 versus 44 +/- 13 minutes; p < 0.05). Control animals exhibited a significantly better neurologic outcome and no paraplegia 24 hours postoperatively. We conclude that the use of SNP to treat excessive proximal hypertension may be detrimental to the spinal cord during cross-clamping of the thoracic aorta, resulting in a decline in the ischemic tolerance.
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Affiliation(s)
- A C Cernaianu
- Division of Cardiothoracic Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden 08103
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Mutch WA, Graham MR, Halliday WC, Thiessen DB, Girling LG. Use of neuroanesthesia adjuncts (hyperventilation and mannitol administration) improves neurological outcome after thoracic aortic cross-clamping in dogs. Stroke 1993; 24:1204-10; discussion 1210-1. [PMID: 8342198 DOI: 10.1161/01.str.24.8.1204] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE Using a canine model of thoracic aortic cross-clamping, we compared the incidence and severity of paraplegia with and without standard neuroanesthesia adjuncts (mannitol administration and deliberate hyperventilation). Better outcome was predicted for animals treated with mannitol and hyperventilation. METHODS Nineteen dogs (mean +/- SD weight, 21 +/- 3 kg) were anesthetized with methohexital to an isoelectric electroencephalogram. Animals were randomized to group C (control; n = 9) or group M (mannitol administration and deliberate hyperventilation; n = 10). In group C, animals were maintained normocapnic (PaCO2, 38 to 42 mm Hg). In group M, animals were hyperventilated to a PaCO2 of 28 to 32 mm Hg and received mannitol 2 g.kg-1 during surgical preparation, then 1 g.kg-1.h-1 by continuous infusion. The thoracic aorta was cross-clamped for 30 minutes. Systemic hemodynamics, cerebrospinal fluid pressure, and arterial blood gases were measured at (1) baseline, (2) 2 minutes after cross-clamp, (3) 20 minutes after cross-clamp, (4) 5 minutes after cross-clamp release, and (5) 30 minutes after resuscitation. No attempt was made to control the hemodynamic consequences of cross-clamping in either group. With release of the cross-clamp, PaCO2 was not controlled in group C; in group M the minute ventilation was further increased to maintain PaCO2 constant. At precisely 24 hours after cross-clamp the animals were assessed for incidence and severity of paraplegia, using the Tarlov score, by an observer unaware of the experimental protocol. The animals were killed, and the entire spinal cord was removed for histological assessment. Multiple sections of the lumbar spinal cord were processed and stained with hematoxylin and eosin. RESULTS With application of the cross-clamp, cerebrospinal fluid pressure and central venous pressure increased significantly in both groups. However, in group M the maximal mean cerebrospinal fluid pressure never exceeded baseline values in group C. With cross-clamp release, spinal cord perfusion pressure (distal mean aortic pressure minus mean cerebrospinal fluid pressure) was significantly greater in group M (86 +/- 23 vs 65 +/- 17 mm Hg; P = .0017 between groups). Acid-base balance was better maintained in group M. The incidence and severity of paraplegia were significantly lower in group M (P = .043; Mann-Whitney rank-sums test, two-tailed). In this group 10 of 10 animals could walk and 4 of 10 had complete recovery. In group C 4 of 9 animals were paraplegic. There was a strong negative correlation between the Tarlov score and the ratio of dead to total anterior spinal cord neurons in the lumbar region as assessed by light microscopy (P = .0004; Spearman's rank test). CONCLUSIONS We conclude that a protocol using standard neuroanesthesia adjuncts (mannitol administration and deliberate hyperventilation) is associated with improved neurological outcome after thoracic aortic cross-clamping of 30 minutes' duration in dogs anesthetized with methohexital.
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Affiliation(s)
- W A Mutch
- Department of Anesthesia, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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Murray MJ, Bower TC, Oliver WC, Werner E, Gloviczki P. Effects of cerebrospinal fluid drainage in patients undergoing thoracic and thoracoabdominal aortic surgery. J Cardiothorac Vasc Anesth 1993; 7:266-72. [PMID: 8518371 DOI: 10.1016/1053-0770(93)90003-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cerebrospinal fluid (CSF) drainage has been reported to protect the spinal cord during surgical procedures requiring thoracic aortic cross-clamping. In 1986, CSF pressure monitoring and drainage was begun in an attempt to reduce the incidence of paraplegia associated with surgical repair of descending thoracic and thoracoabdominal aortic aneurysms (TAAA). These Group II patients (n = 50) were retrospectively compared to Group I patients (n = 49) who had undergone similar surgical procedures in the previous 3 years before CSF monitoring was introduced into this practice. Group II patients had intrathecal catheters placed for monitoring of CSF pressure and drainage of CSF to maintain the pressure < or = 15 mmHg. Seven patients (four in Group I, three in Group II) died before recovering from the anesthetic. Of the 47 patients in Group II who survived, none had clinically apparent complications such as an epidural hematoma or meningitis from the intrathecal catheter. The mean aortic cross-clamp time was 58.6 +/- 30.5 minutes (mean +/- SD) in Group I versus 65 +/- 42.6 minutes in Group II. Twenty-three patients in Group I and 16 patients in Group II had a shunt to the distal aorta. To maintain a CSF pressure of < or = 15 mmHg in Group II, an average of 46.9 +/- 6.9 mL of CSF was withdrawn. Of the 45 survivors in Group I, 4 developed a spinal cord deficit; the number of patients with spinal cord deficit in Group II was 4 out of the 47 who survived.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M J Murray
- Division of Cardiovascular and Thoracic Anesthesiology, Mayo Clinic, Rochester, MN 55905
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Affiliation(s)
- M Nugent
- Department of Anesthesia, Medical College of Ohio, Toledo 43699
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Woloszyn TT, Marini CP, Coons MS, Nathan IM, Jacobowitz IJ, Cunningham JN. A multimodality approach lengthens warm ischemic time during aortic cross-clamping. J Surg Res 1992; 52:15-21. [PMID: 1548863 DOI: 10.1016/0022-4804(92)90272-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To evaluate the effects of exsanguination, cerebrospinal fluid drainage (CSFD), steroids alone and in conjunction with CSFD on spinal cord perfusion pressure (SCPP), and neurological outcome following 70 min of normothermic spinal cord ischemia, we monitored proximal (Px BP) and distal (Ds BP) aortic blood pressure, cerebrospinal fluid pressure, and somatosensory evoked potentials (SEP) in 29 mongrel dogs. In all animals Px BP during aortic cross-clamping was controlled with partial exsanguination (40-50% circulating blood volume). Dogs were randomized into four groups (gp): gp 1 (n = 6) control; gp 2 (n = 8) steroids only (methylprednisolone 30 mg/Kg 10 min before aortic occlusion and 4 hr later); gp 3 (n = 8) CSFD only; gp 4 (n = 7) steroids and CSFD. Partial exsanguination effectively controlled Px BP during aortic cross-clamping in all groups. After the statistically significant decrease from preclamp values, mean Px BP did not differ among groups (78.9, 81.2, 80.5, and 80.3 mm Hg, respectively, P greater than 0.05). Mean Ds BP decreased from systemic values to 12.6, 16.8, 16.7, and 17 mm Hg, respectively, after aortic occlusion (P less than 0.05); these values did not differ from one another. CSFP did not change significantly from its baseline value while the aorta was cross-clamped in gp 1; CSFP was significantly reduced to 6.2 mm Hg in gp 2, steroid-treated animals (P less than 0.05 vs gp 1); a further significant reduction in CSFP was noted in gp 3 and 4 undergoing CSFD (0.07 and 0.67 mm Hg, respectively, P less than 0.05 vs gp 1 and 2).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T T Woloszyn
- Department of Surgery, Maimonides Medical Center, Brooklyn, New York 11219
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