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Christiansson, Lennart
Publications (10 of 11) Show all publications
Christiansson, L., Ulus, A. T., Hellberg, A., Bergqvist, D., Wiklund, L. & Karacagil, S. (2001). Aspects of the spinal cord circulation as assessed by intrathecal oxygen tension monitoring during various arterial interruptions in the pig. Journal of Thoracic and Cardiovascular Surgery, 121(4), 762-772
Open this publication in new window or tab >>Aspects of the spinal cord circulation as assessed by intrathecal oxygen tension monitoring during various arterial interruptions in the pig
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2001 (English)In: Journal of Thoracic and Cardiovascular Surgery, ISSN 0022-5223, E-ISSN 1097-685X, Vol. 121, no 4, p. 762-772Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE: We sought to study the effect of various modes of interruption of the spinal cord blood supply on intrathecal oxygenation.

METHODS: In 24 pigs intrathecal PO (2), PCO (2), and pH were continuously monitored with a multiparameter catheter (Paratrend 7, Biomedical Sensors; Diametrics Medical, Inc, St Paul, Minn) during and after aortic crossclamping or selective interruption of segmental arteries and proximal collateral circulation.

RESULTS: Proximal aortic clamping (n = 6) produced complete ischemia, whereas a second clamp close to the celiac trunk (n = 4) partly protected against spinal cord ischemia. This is explained by prevention of the steal phenomenon in the excluded part of the aorta. Adding clamps to the subclavian arteries (n = 6) created complete spinal ischemia as the collateral circulation was interrupted. In another group (n = 4) all segmental arteries below T5 were occluded with no reaction in the intrathecal variables. Additional selective clamping of supreme intercostal arteries (n = 4) showed the relative importance of the subclavian and vertebral collateral pathways.

CONCLUSIONS: Continuous intrathecal PO (2) was monitored during various modes of interruption of the spinal cord blood supply. This provided insight into the ischemia mechanisms and relative importance of the segmental contribution and proximal collateral pathways of the spinal cord circulation in pigs. A short literature review is given, and aspects of comparative anatomy are discussed.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58432 (URN)10.1067/mtc.2001.112466 (DOI)11279419 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-12-01Bibliographically approved
Christiansson, L., Ulus, A. T., Hellberg, A., Bergqvist, D., Wiklund, L. & Karacagil, S. (2001). Increased FiO2 improves intrathecal oxygenation during thoracic aortic cross-clamping in pigs. Scandinavian Cardiovascular Journal, 35(2), 147-150
Open this publication in new window or tab >>Increased FiO2 improves intrathecal oxygenation during thoracic aortic cross-clamping in pigs
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2001 (English)In: Scandinavian Cardiovascular Journal, ISSN 1401-7431, E-ISSN 1651-2006, Vol. 35, no 2, p. 147-150Article in journal (Refereed) Published
Abstract [en]

OBJECTIVES: To investigate the effect of 100% oxygen ventilation on cerebrospinal fluid (CSF) oxygenation in 11 pigs during thoracic aortic cross-clamping.

DESIGN: An aorto-aortic shunt was used for control of central hemodynamics and study of hypoperfusion by exsanguination. CSF PO2, PCO2 and pH were continuously monitored before and during clamping. The changes in hemodynamic parameters and intrathecal gas tensions in response to variations in proximal mean aortic pressure and fraction of inspired oxygen (FiO2) were recorded.

RESULTS: Baseline CSF PO2 decreased from 4.8 +/- 1.9 to 2.6 +/- 2.2 kPa following aortic occlusion. Increasing FiO2 to 1.0 resulted in a significant increase in CSF PO2 to 4.1 +/- 3.0 with a return to 2.7 +/- 2.1 kPa after reducing FiO2 to 0.4 again. The same variations in FiO2 did not induce any significant changes in CSF PO2 during hypotension.

CONCLUSION: Increased FiO2 during experimental thoracic aortic cross-clamping with stable proximal arterial pressure helps to maintain CSF PO2, whereas severe hypotension could not be compensated for by hyperoxemia.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58429 (URN)11405492 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-12-01Bibliographically approved
Christiansson, L., Hellberg, A., Koga, I., Thelin, S., Bergqvist, D., Wiklund, L. & Karacagil, S. (2000). A new method of intrathecal PO2, PCO2, and pH measurements for continuous monitoring of spinal cord ischemia during thoracic aortic clamping in pigs. Surgery, 127(5), 571-576
Open this publication in new window or tab >>A new method of intrathecal PO2, PCO2, and pH measurements for continuous monitoring of spinal cord ischemia during thoracic aortic clamping in pigs
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2000 (English)In: Surgery, ISSN 0039-6060, E-ISSN 1532-7361, Vol. 127, no 5, p. 571-576Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Impaired spinal cord circulation during thoracic aortic clamping may result in paraplegia. Reliable and fast responding methods for intraoperative monitoring are needed to facilitate the evaluation of protective measures and efficiency of revascularization.

METHODS: In 11 pigs, a multiparameter PO2, PCO2, and pH sensor (Paratrend 7, Biomedical Sensors Ltd, United Kingdom) was introduced into the intrathecal space for continuous monitoring of cerebrospinal fluid (CSF) oxygenation during thoracic aortic cross-clamping (AXC) distal to the left subclavian artery. A laser-Doppler probe was inserted into the epidural space for simultaneous measurements of spinal cord flux. Registrations were made before and 30 minutes after clamping and 30 and 60 minutes after declamping. The same measuring points were used for systemic hemodynamic and metabolic data acquisition.

RESULTS: The mean CSF PO2 readings of 41 mm Hg (5.5 kPa) at baseline decreased within 3 minutes to 5 mm Hg (0.7 kPa) during AXC (P < .01). Spinal cord flux measurement responded immediately in the same way to AXC. Both methods indicated normalization of circulation during declamping. Significant (P < .01) changes were also observed in the CSF metabolic parameters PCO2 and pH.

CONCLUSIONS: In this experimental model of spinal ischemia by AXC, online monitoring of intrathecal PO2, PCO2, and pH showed significant changes and correlated well with epidural laser-Doppler flowmetry (P < .01).

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-62364 (URN)10.1067/msy.2000.105036 (DOI)10819067 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-11-30Bibliographically approved
Hellberg, A., Christiansson, L., Tulga Ulus, A., Bergqvist, D., Wiklund, L. & Karacagil, S. (2000). A prolonged spinal cord ischaemia model in pigs. Passive shunting offers stable central haemodynamics during aortic occlusion. European Journal of Vascular and Endovascular Surgery, 19(3), 318-323
Open this publication in new window or tab >>A prolonged spinal cord ischaemia model in pigs. Passive shunting offers stable central haemodynamics during aortic occlusion
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2000 (English)In: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 19, no 3, p. 318-323Article in journal (Refereed) Published
Abstract [en]

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.

Keywords
Experimental model, Aortic occlusion, Spinal cord ischaemia
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58005 (URN)10.1053/ejvs.1999.1027 (DOI)10753699 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-12-01Bibliographically approved
Hellberg, A., Koga, I., Christiansson, L., Stiernström, H., Wiklund, L., Bergqvist, D. & Karacagil, S. (2000). Influence of segmental spinal cord perfusion on intrathecal oxygen tension during experimental thoracic aortic crossclamping. Journal of Vascular Surgery, 31(1 Pt 1), 164-170
Open this publication in new window or tab >>Influence of segmental spinal cord perfusion on intrathecal oxygen tension during experimental thoracic aortic crossclamping
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2000 (English)In: Journal of Vascular Surgery, ISSN 0741-5214, Vol. 31, no 1 Pt 1, p. 164-170Article in journal (Refereed) Published
Abstract [en]

PURPOSE: The purpose of this study was to evaluate the possibility of identifying alterations in blood supply to the spinal cord during thoracic aortic crossclamping.

METHODS: In 17 pigs, a multiparameter PO(2), PCO(2,) and pH sensor was introduced into the intrathecal space for continuous monitoring of cerebrospinal fluid (CSF) oxygenation during aortic crossclamping. An epidural laser Doppler probe was used to measure spinal cord flux. After insertion of an aortic shunt from the left subclavian to the left iliac artery and interruption of the right subclavian and lumbar arteries (L2-L5), the thoracic aorta just distal to the left subclavian artery was clamped for 60 minutes. By placement of the distal aortic crossclamping below the level of L1 in group A (n = 9 animals), perfusion of only the abdominal visceral arteries was maintained. In group B (n = 8 animals), the distal aortic crossclamping was above the level of T12, and thus some spinal cord perfusion was maintained through the aortic shunt.

RESULTS: The significant decrease in CSF PO(2) was observed within 3 minutes after the placement of the proximal aortic crossclamping and was normalized in all animals after establishment of the shunt flow. In group A, distal aortic crossclamping caused a decrease in CSF PO(2) with at least 50% of the preclamping values within 3 minutes. The mean CSF PO(2) of 2.99 +/- 0.70 kPa at 60 minutes of distal aortic crossclamping in group B was significantly higher than in group A (0.11 +/- 0.11 kPa; P <. 001). In group A, PCO(2) measurements showed no significant changes in 3 minutes after distal aortic crossclamping but revealed significantly higher values at 30 and 60 minutes compared with group B. Spinal cord flux values showed similar changes as CSF PO(2) during the whole experiment in both groups.

CONCLUSION: In this experimental model of aortic crossclamping, continuous CSF oxygen tension monitoring allows rapid detection of alterations in spinal cord circulation.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58120 (URN)10.1016/S0741-5214(00)70078-4 (DOI)10642719 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2015-06-09Bibliographically approved
Koga, I., Stiernstrom, H., Christiansson, L. & Wiklund, L. (2000). Intraperitoneal tonometry for detection of regional enteric ischaemia [InProcess Citation]. Acta Anaesthesiol. Scand., 44, 985
Open this publication in new window or tab >>Intraperitoneal tonometry for detection of regional enteric ischaemia [InProcess Citation]
2000 (English)In: Acta Anaesthesiol. Scand., Vol. 44, p. 985-Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58119 (URN)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2015-06-09
Koga, I., Stiernstrom, H., Christiansson, L. & Wiklund, L. (2000). Intraperitoneal tonometry for detection of regional enteric ischemia. Acta Anaesthesiologica Scandinavica, 44(8), 985-990
Open this publication in new window or tab >>Intraperitoneal tonometry for detection of regional enteric ischemia
2000 (English)In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, Vol. 44, no 8, p. 985-990Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-90927 (URN)
Available from: 2003-10-16 Created: 2003-10-16 Last updated: 2015-06-09Bibliographically approved
Christiansson, L., Hellberg, A., Svensson, B. A., Bergqvist, D., Wiklund, L. & Karacagil, S. (2000). Relationship between intrathecal oxygen tension and ultrastructural changes in the spinal cord during experimental aortic clamping. European Journal of Vascular and Endovascular Surgery, 19(4), 413-420
Open this publication in new window or tab >>Relationship between intrathecal oxygen tension and ultrastructural changes in the spinal cord during experimental aortic clamping
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2000 (English)In: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 19, no 4, p. 413-420Article in journal (Refereed) Published
Abstract [en]

OBJECTIVES: To investigate spinal cord ultrastructure related to cerebrospinal fluid (CSF) oxygenation.

DESIGN: experimental aortic occlusion model with intrathecal oxygen tension monitoring.

MATERIALS AND METHODS: Two groups of pigs underwent proximal (P) or double (D) aortic occlusion for 30 min followed by 1 h of reperfusion. In a third group (I) segmental arteries distal to T3 were clamped for 90 min. A thin pO(2), pCO(2) and pH sensor was placed intrathecally for continuous monitoring of CSF. Spinal cord segments were studied by electron microscopy (EM).

RESULTS: In group P, CSF-pO(2)rapidly decreased during clamping and major changes in pH and pCO(2)were seen. EM demonstrated neuronal degeneration with loss of cellular integrity and severe affection of organelles. In the group D, CSF oxygenation decreased to about half, but with only moderate changes in the metabolic parameters. Group I showed no significant changes in CSF measurements. The latter groups were similar at EM, showing only mild mitochondrial changes.

CONCLUSIONS: The level of CSF oxygenation during aortic cross-clamping or segmental artery interruption seems to correlate with ultrastructural changes in the spinal cord. This online intrathecal monitoring technique may provide valuable information on spinal cord circulation during thoracoabdominal aortic surgery.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58064 (URN)10.1053/ejvs.1999.1055 (DOI)10801376 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-12-01Bibliographically approved
Koga, I., Stiernstrom, H., Christiansson, L. & Wiklund, L. (1999). Intraperitoneal and sigmoid colon tonometry in porcine hypoperfusion and endotoxin shock models. Acta Anaesthesiologica Scandinavica, 43(7), 702-707
Open this publication in new window or tab >>Intraperitoneal and sigmoid colon tonometry in porcine hypoperfusion and endotoxin shock models
1999 (English)In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, Vol. 43, no 7, p. 702-707Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-90926 (URN)
Available from: 2003-10-16 Created: 2003-10-16 Last updated: 2015-06-09Bibliographically approved
Christiansson, L., Karacagil, S., Thelin, S., Hellberg, A., Tyden, H., Wiklund, L. & Bergqvist, D. (1998). Continuous monitoring of intrathecal pO2, pCO2 and pH during surgical replacement of type II thoracoabdominal aortic aneurysm. European Journal of Vascular and Endovascular Surgery, 15(1), 78-81
Open this publication in new window or tab >>Continuous monitoring of intrathecal pO2, pCO2 and pH during surgical replacement of type II thoracoabdominal aortic aneurysm
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1998 (English)In: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 15, no 1, p. 78-81Article in journal (Refereed) Published
Keywords
Aortic surgery, Thoracoabdominal aneurysm, Paraplegia, Spinal cord ischaemia, Intrathecal monitoring
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-58030 (URN)10.1016/S1078-5884(98)80076-2 (DOI)9519004 (PubMedID)
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-12-01Bibliographically approved
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