Infrarenal Aortic Cross-clamping Research Articles

Vascular control by infrarenal aortic cross-clamping in placenta accreta spectrum disorders: description of technique.

We describe a novel surgical technique in 31 women with histopathologically confirmed placenta accreta spectrum (PAS) disorders managed by a multidisciplinary team using a prophylactic infrarenal abdominal aortic cross-clamping technique during caesarean hysterectomy. We conclude that this new surgical procedure is a relatively safe technique to potentially control operative blood loss. Our work may stimulate others to develop protocols assessing this innovative technique to improve the surgical outcome of PAS disorders.

The Influence of Suprarenal Aortic Cross-clamping on Perioperative and Follow-up Results of Open Repair of Abdominal Aortic Aneurysm

The objective was to retrospectively assess the perioperative and long-term outcomes in patients operated on with open repair of abdominal aortic aneurysm (AAA) with or without suprarenal aortic cross-clamping in a single-center experience. From January 2008 to December 2018, 1608 consecutive open and endovascular interventions for AAA were performed. Data concerning these interventions were prospectively recorded; a retrospective analysis of the database was performed and 540 elective open interventions for unruptured AAA were found, in 73 cases with suprarenal aortic cross-clamping (group 1) and in 467 cases with infrarenal aortic cross-clamping (group 2). The two groups were compared in terms of clinical, anatomic, and surgical characteristics and perioperative (<30 days) outcomes with χ2 test; follow-up results were compared with Kaplan-Meier curves and log-rank test. There were no differences between the two groups in terms of demographics, risk factors, and comorbidities, except for a higher percentage of female patients in group 1 than in group 2 (16.2% and 9.1%, respectively; P = .05). Mean preoperative estimated glomerular filtration rate was similar in the two groups as well. Most patients in both groups had a bifurcated aortobi-iliac graft; in group 1, 22 patients had a unilateral or bilateral renal revascularization, whereas in 51 cases, the ostium of one or both renal arteries was included in the proximal anastomosis. The mean time of renal ischemia in group 1 was 16 ± 12 minutes. Patients in group 1 had a longer time of intensive care unit stay than patients in group 2, but the overall length of stay was similar. Perioperative mortality rates were 4.1% in group 1 and 2.7% in group 2 (P = .5); nonfatal major complications occurred in 14 patients in group 1 (19%) and in 69 patients in group 2 (14.5%; P = .3). Follow-up was available in 512 patients (95%), with a median duration of 48 months (range, 1-144 months). Estimated 7-year survival rates were 51.5% in group 1 and 76.5% in group 2 (P < .001; log-rank, 15.3), whereas the corresponding figures in terms of freedom from AAA-related complications were 63.5% and 85.5% (P = .002; log-rank, 9.5). Moreover, patients in group 1 were more likely than patients in group 2 to undergo a reintervention at 7-year follow-up. In patients with complex AAA requiring suprarenal aortic cross-clamping, a significant increase of long term mortality, AAA-related complications, and reintervention was found in comparison with patients undergoing infrarenal aortic clamping.

Long-term Efficacy of EVAR in Patients Aged Less Than 65 Years with an Infrarenal Abdominal Aortic Aneurysm and Favorable Anatomy

The aim of this study was to compare early and long-term outcomes of endovascular aneurysm repair (EVAR) versus open surgical repair (OSR) in patients aged ≤65 years. Data of patients aged ≤65years undergoing infrarenal abdominal aortic aneurysm repair, between 2005 and 2013, were retrospectively reviewed. All EVAR procedures were performed according to the instruction for use, and only OSR procedures with an infrarenal aortic cross-clamping were included in the study. In this group of 115 patients (EVAR: 58 patients, 51% and OSR: 57 patients, 49%), EVAR and OSR patients had similar comorbidities, except for obesity (EVAR: 38% vs. OSR: 19%; P=0.03). A stay in the intensive care unit (ICU) was necessary in 19% of patients with EVAR versus 79% with OSR (P=0.001), and the amount of blood transfusion was 236±31mL for EVAR versus 744±98mL for OSR (P=0.001). The hospital stay was 4±2days for EVAR versus 9±6days for OSR (P=0.03). The overall 30-day mortality was 1% (EVAR: 0% vs. OSR: 2%; P=0.30). Five patients (4%) required reinterventions within 30 days (EVAR: 0% vs. OSR: 8%, P=0.001). The mean follow-up was 86±38months. Freedom from reintervention at 10years after EVAR was 81% versus OSR 74%; (P=0.77). Late reinterventions were reported in 13 patients (23%) with OSR and in 10 patients (17%) with EVAR. Postoperative retrograde ejaculation occurred more often in patients with OSR (31%) versus EVAR (2%) (P=0.001). During the follow-up, cancer was found in 19 (17%) patients with no difference between EVAR and OSR (P=0.83). The global survival at 10years was 72% (EVAR: 79% vs. OSR: 70%; P=0.94). In this study, EVAR was associated with a shorter hospital stay, less need for the ICU, and less early reinterventions than OSR. Survival and reinterventions during the follow-up were not significantly different between EVAR and OSR. According to theseresults, EVAR may be considered for patients aged ≤65years with a favorable anatomy.

Outcomes of Late Open Conversion after Endovascular Abdominal Aneurysm Repair.

Objective: To review our experience with a late open conversion as a final option for an endograft infection and aneurysm expansion after endovascular aneurysm repair (EVAR), especially in endoleaks for which radiological intervention is impossible.Materials and Methods: In this retrospective study, 13 late open conversions out of 513 consecutive patients treated by EVAR were analyzed. Indications for an open conversion were aneurysm enlargement, including all endoleaks, endograft migration, and endograft infection. The patients’ data on demographics, operative details, and outcomes were reviewed.Results: Indications for a late open conversion included endoleaks, infection, and migration in 61.5%, 30.8%, and 7.7% of patients, respectively. The median interval from the initial EVAR was 32.4 months. Complete endograft explantation was performed in four patients with an endograft infection. In endoleak cases, the endograft was partially preserved and a neo-neck was used. Sacotomy and branch ligation were performed in one case. One major operative complication was an aortic injury during infrarenal aortic cross-clamping in an endograft migration case. There was no operative mortality.Conclusion: A late open conversion after EVAR is valuable as a final option. The aortic cross-clamp site, especially in endograft migration cases, should be carefully considered. To avoid aneurysm-related events, graft replacement is recommended, if possible.

Neuroprotective Effects of Tocilizumab on Experimentally-Induced Spinal Cord Ischemia-Reperfusion Injury

We aimed to evaluate neuroprotective effects of tocilizumab on spinal cord ischemia-reperfusion (I/R) injury. Our study design was an experimental rabbit spinal cord I/R injury model, and the setting was at the Animal Research Laboratory, Necmettin Erbakan University, Meram School of Medicine, Konya, Turkey. Twenty-four adult New Zealand rabbits were randomly divided into 3 groups: Group 1, control group (n=8); Group 2, I/R group, and Group 3 (n= 8) I/R injury+ tocilizumab (4 mg/kg, ip) treatment group. Spinal cord I/R injury repair was performed by infrarenal aortic cross clamping. On neurologic evaluation, spinal cord tissue plasma tumor necrosis factor alpha (TNFα), total antioxidant status (TAS), total oxidant status (TOS), thiobarbituric acid reactive substances (TBARS), interleukin 6 (IL-6), interleukin 10 (IL-10) levels were analyzed. Spinal cord neuronal damage score and apoptotic cell count were also investigated. I/R injury significantly increases the plasma and spinal cord tissue TNFα, TOS, TBARS, and IL-6 levels and decreases the plasma and spinal cord tissue TAS and IL-10 levels. Tocilizumab treatment significantly reduces the plasma and spinal cord tissue TNFα, TOS, TBARS, IL-6 levels and increases plasma and tissue TAS and IL-10 levels. I/R injury significantly increases spinal cord neuronal damage score and apoptotic cell count. Tocilizumab treatment significantly reduces spinal cord neuronal damage score and apoptotic cell count. Neurologic examination scores at 24, 48, and 72 hours were significantly better in the treatment group when compared with the I/R group. This study shows significant neuroprotective effects of tocilizumab on rabbit spinal cord I/R injury.

Targeted Temperature Management With Total Liquid Ventilation After Ischemic Spinal Cord Injury

Ischemic spinal cord injury is a devastating condition after aortic surgery. We determined whether ultrafast and short whole-body hypothermia provided by total liquid ventilation (TLV) attenuated lower limb paralysis after aortic cross-clamping with a targeted temperature management at 33°C versus 36°C. Anesthetized rabbits were submitted to infrarenal aortic cross-clamping during 15 min. A control group (n= 7) was maintained at normothermia (38°C to 38.5°C) with conventional mechanical ventilation. In TLV groups, TLV was started after reperfusion and maintained during 30 min with a target temperature at either 33°C or 36°C (TLV-33°C and TLV-36°C, respectively; n= 7 in each condition). After TLV, animals were resumed to conventional ventilation. Hypothermia was maintained during 120 min, before rewarming and awakening. Hind limb motor function was assessed with modified Tarlov score at day 2 and infarct size in the spinal cord was determined using triphenyltetrazolium chloride staining. Target temperature was achieved within 20 minutes in the two TLV groups. At day 2, the modified Tarlov score was significantly lower in the control group, as compared with TLV-33°C and TLV-36°C groups (0.0 ± 0.0 versus 3.1 ± 0.7 and 2.6 ± 0.6, respectively). The infarct size of the spinal cord was also significantly higher in the control group compared with TLV-33°C and TLV-36°C groups (75% ± 10% versus 32% ± 7% and 28% ± 10%, respectively). Neither motor function nor infarct size differed significantly between TLV-33°C and TLV-36°C groups. Ultrafast hypothermic TLV attenuates spinal cord injury when applied after ischemic insult. Neurological outcome was similar with targeted temperature management at either 33°C or 36°C.

Pentoxifylline attenuates the local andsystemic inflammatory response afterinfrarenal abdominal aortic ischemia-reperfusion.

We studied the new anti-inflammatory effects of non-specific phosphodiesterase (PDE) inhibitor pentoxifylline (PTX) on ischaemia-reperfusion injury and postconditioning of the lower extremities. We aimed to examine the oxidative stress parameters (OSP), the inflammatory response and the changes in structure of skeletal muscle after revascularization surgery. 50 Wistar rats in five groups underwent a 60 min infrarenal aortic cross clamping. After the ischaemia in IR+PC group ischemic postconditioning was performed, intermittent 15 seconds reperfusion, 15 seconds ischaemic periods were applied four times. The ischemic phase was followed by a 120 min of reperfusion. In IR+PTX group the animals were treated with PTX. In IR+PC+PTX group both ischemic postconditioning and PTX treatment were performed. Blood samples and biopsy from quadriceps muscle were collected. Plasma malondialdehyde, reduced glutathione, -SH-groups, TNF-alpha, IL-6 concentrations and superoxide dismutase enzyme activity were measured. The levels of OSP and the inflammatory proteins were significantly higher in the IR group. PTX treatment and PC could significantly decrease the levels of OSP and inflammatory proteins. When the animals were co-treated with PTX and PC the results were even better. Inhibition of PDE by PTX could markedly decrease the inflammatory response and moderate the ischaemia-reperfusion damages after lower limb ischemia and reperfusion. Administration of PTX could potentiate the beneficial effects of PC.

Hydrogen sulfide ameliorates acute lung injury induced by infrarenal aortic cross-clamping by inhibiting inflammation and angiopoietin 2 release

Infrarenal aortic cross-clamping (IAC) is a common procedure during infrarenal vascular operations. It often causes ischemia-reperfusion injury to lower limbs, resulting in systemic inflammation response and damage to remote organs (particularly lungs). Hydrogen sulfide (H2S) is a gaseous mediator that has been shown to have a protective effect against lung injury. Wistar rats underwent IAC for 2hours, followed by 4hours of reperfusion. GYY4137 (a slow-releasing H2S donor) and dl-propargylglycine (PAG, an inhibitor of cystathionine γ-lyase) were preadministered to rats 1hour before IAC, and their effects on severity of lung injury and related mechanisms were investigated. IAC induced a significant increase in plasma levels of H2S, H2S-synthesizing activity, and cystathionine γ-lyase expression in lung tissues compared with sham operation. Administration of GYY4137 significantly increased the levels of H2S but had little effect on H2S-synthesizing activity, whereas PAG reduced H2S levels and H2S-synthesizing activity. Preadministration of GYY4137 significantly attenuated acute lung injury induced by IAC, evidenced by reduced histologic scores and wet lung contents; improved blood gas parameters; reduced cell counts and protein amounts in bronchoalveolar lavage fluids; and reduced myeloperoxidase activity in lung tissues and plasma levels of tumor necrosis factor α, interleukin 6, and interleukin 1β. However, PAG further aggravated the severity of lung injury and displayed opposite effects to GYY4137. In exploration of the mechanisms, we found that IAC increased the release of angiopoietin 2 (Ang2) and its expression in lung tissues. GYY4137 attenuated the increase of Ang2 release and expression and increased the phosphorylation of Akt and the activation of its downstream factors, glycogen synthase kinase 3β and ribosomal protein S6 kinase; PAG showed opposite effects. The study indicates that H2S may play a protective role in IAC-induced acute lung injury in rats by inhibiting inflammation and Ang2 release.

Ischemia and reperfusion injury of the spinal cord: experimental strategies to examine postischemic paraplegia

Thoracoabdominal aortic replacement, necessary in case of injuries, aneurysms and dissections, shows a high complication rate as a consequence of the perioperative ischemia / reperfusion-sequence (I/R). Clamping above and below the lesion leads to the spinal cord suffering from ischemia. Clamping times of less than 30 minutes show only a small risk of neurological deficit, while longer periods increase paraplegia rates disproportionately. The subsequent reperfusion as a second hit causes additional damage to the spinal cord. Up to 30 % of all patients who require being treated in the thoracoabdominal part of the aorta suffer from paraplegia within the first 24 postoperative hours (Kahn et al., 2012).

Inhibition of Glutathione S-Transferase by Ethacrynic Acid Augments Ischemia-Reperfusion Damage and Apoptosis and Attenuates the Positive Effect of Ischemic Postconditioning in a Bilateral Acute Hindlimb Ischemia Rat Model

Aims: We studied the effects of the inhibition of the endogene antioxidant glutathione-S-transferase (GST) by ethacrynic acid (EA) on ischemia-reperfusion (IR) injury and postconditioning (PC) in the lower extremities. We aimed to examine the oxidative stress parameters (OSP), inflammatory response and activation of proapoptotic signaling proteins (PSP) after revascularization surgery. Methods: Sixty Wistar rats were divided into 6 groups: control, IR, PC, EA-control, IR and administration of EA (IR/EA) and PC and administration of EA (PC/EA). The IR, PC, IR/EA and PC/EA groups underwent 60 min of infrarenal aortic cross-clamping. After that, PC was performed in the PC and PC/EA groups. In 3 of the groups, the animals were treated with EA (EA-control, IR/EA and PC/EA groups) as well. The ischemia was followed by 120 min of reperfusion. Blood samples and biopsy specimens were collected from the quadriceps muscle. Plasma malondialdehyde, reduced glutathione, thiol/sulfhydryl group levels, TNF-α and IL-6 concentrations and superoxide-dismutase enzyme activity were measured. Results: The levels of the OSP and the inflammatory proteins were higher in the EA-administered groups. The ratio of phosphorylated PSP was higher in the EA-administered groups and the protective effect of PC did not develop. Conclusions: Inhibition of GST by EA augmented the IR damage. GST inhibition was associated with a different activation of the mitogen-activated protein kinases and the PSP, regulating these pathways in the process of apoptosis and PC.

Borax Partially Prevents Neurologic Disability and Oxidative Stress in Experimental Spinal Cord Ischemia/Reperfusion Injury

The aim of this study is to investigate the potential effects of borax on ischemia/reperfusion injury of the rat spinal cord. Twenty-one Wistar albino rats were divided into 3 groups: sham (no ischemia/reperfusion), ischemia/reperfusion, and borax (ischemia/reperfusion + borax); each group was consist of 7 animals. Infrarenal aortic cross clamp was applied for 30 minutes to generate spinal cord ischemia. Animals were evaluated functionally with the Basso, Beattie, and Bresnahan scoring system and inclined-plane test. The spinal cord tissue samples were harvested to analyze tissue concentrations of nitric oxide, nitric oxide synthase activity, xanthine oxidase activity, total antioxidant capacity, and total oxidant status and to perform histopathological examination. At the 72nd hour after ischemia, the borax group had significantly higher Basso, Beattie, and Bresnahan and inclined-plane scores than those of ischemia/reperfusion group. Histopathological examination of spinal cord tissues in borax group showed that treatment with borax significantly reduced the degree of spinal cord edema, inflammation, and tissue injury disclosed by light microscopy. Xanthine oxidase activity and total oxidant status levels of the ischemia/reperfusion group were significantly higher than those of the sham and borax groups (P < .05), and total antioxidant capacity levels of borax group were significantly higher than those of the ischemia/reperfusion group (P < .05). There was not a significantly difference between the sham and borax groups in terms of total antioxidant capacity levels (P > .05). The nitric oxide levels and nitric oxide synthase activity of all groups were similar (P > .05). Borax treatment seems to protect the spinal cord against injury in a rat ischemia/reperfusion model and improve neurological outcome.

Effects of curcumin on acute spinal cord ischemia-reperfusion injury in rabbits

The object of this study was to conduct a prospective, randomized, laboratory investigation of the neuroprotective effects of curcumin functionally, biochemically, and histologically in an experimental acute spinal cord ischemia-reperfusion injury on rabbits. Eighteen rabbits were randomly assigned to 1 of 3 groups: the sham group, the ischemia-reperfusion group, or the curcumin group. Spinal cord ischemia was induced by applying an infrarenal aortic cross-clamp for 30 minutes. At 48 hours after ischemia, neurological function was evaluated with modified Tarlov criteria. Biochemical changes in the spinal cord and plasma were observed by measuring levels of malondialdehyde (MDA), advanced oxidation protein products (AOPP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), nitrite/nitrate, and tumor necrosis factor-α (TNF-α). Histological changes were examined with H & E staining. Immunohistochemical staining with antibodies against caspase-3 was performed to evaluate cell apoptosis after ischemia. In the curcumin group, neurological outcome scores were statistically significantly better compared with the ischemia-reperfusion group. In the ischemia-reperfusion group, MDA, AOPP, and nitrite/nitrate levels were significantly elevated in the spinal cord tissue and the plasma by the induction of ischemia-reperfusion. The curcumin treatment significantly prevented the ischemia-reperfusion-induced elevation of nitrite/nitrate and TNF-α. In addition, the spinal cord tissue and the plasma SOD, GSH, and CAT levels were found to be preserved in the curcumin group and not statistically different from those of the sham group. Histological evaluation of the tissues also demonstrated a decrease in axonal damage, neuronal degeneration, and glial cell infiltration after curcumin administration. Although further studies including different dose regimens and time intervals are required, curcumin could attenuate a spinal cord ischemia-reperfusion injury in rabbits via reducing oxidative products and proinflammatory cytokines, as well as increasing activities of antioxidant enzymes and preventing apoptotic cell death.

Simultaneous investigation of hemodynamic, microcirculatory and arterio-venous micro-rheological parameters in infrarenal or suprarenal aortic cross-clamping model in the rat

We aimed to investigate hemodynamic, microcirculatory and hemorheological consequence of infrarenal or suprarenal aortic cross-clamping (IRAXC, SRAXC) in the rat. We hypothesized that the magnitude of the changes are different. Twenty-one male rats were randomized into Control, IRAXC or SRAXC groups. Under anesthesia the right carotid artery was cannulated for monitoring heart rate and mean arterial pressure, then median laparotomy was performed. In AXC groups the abdominal aorta and the caudal caval vein were atraumatically clamped for 60 minutes below or above the renal vessels. Before and just after the ischemia, in the 30th and 60th minutes of the reperfusion besides hemodynamic test, laser Doppler flowmetry was used on the liver's, small-intestine's and the kidney's surface, then arterial (cannulated carotid artery) and venous (lateral tail vein) blood samples were taken for determining hematological, acid-base, erythrocytes' deformability, osmoscan and aggregation parameters. We found that when hemodynamic changes were prominent, microcirculatory or hemorheological parameters did not show such large differences. However, every parameter changed in various manners, showing more or less differences between IRAXC and SRAXC groups. Although the largest deviations were observable in SRAXC group, the acid-base and hemodynamic alterations were much more expressed than the micro-rheological ones. Further investigations of in vivo relations-correlations of changes in hemodynamic, microcirculatory, metabolic and hemorheological factors need further studies providing simultaneous monitoring possibilities.

Predicting Fluid Responsiveness During Infrarenal Aortic Cross-Clamping in Pigs

Infrarenal aortic cross-clamping (ACC) induces hemodynamic disturbances that may affect respiratory-induced variations in stroke volume and, therefore, affect the ability of dynamic parameters such as pulse-pressure variation (PPV) to predict fluid responsiveness. Since this issue has not been investigated yet to authors' knowledge, the hypothesis was tested that ACC may change PPV and impair its ability to predict fluid responsiveness. Prospective laboratory experiment. A university research laboratory. Nineteen anesthetized and mechanically ventilated pigs. Two courses of volume expansion were performed using 500 mL of saline before and during ACC. Animals were monitored using a systemic arterial catheter, and a pulmonary arterial catheter (stroke volume, central venous pressure, pulmonary arterial occlusion pressure). Animals were defined as responders to volume expansion if stroke volume increased ≥ 15%. Before ACC, 13 animals were responders. Fluid responsiveness was predicted by a PPV ≥ 14% with a sensitivity of 77% (95% CI = 46%-95%) and a specificity of 83% (95% CI = 36%-97%). The area under the receiver operating characteristic curve was 0.90(95% CI = 0.67-0.99) and was higher than those generated for central venous pressure and pulmonary arterial occlusion pressure. ACC induced an increase in PPV (p<0.0005). During ACC, 8 animals were responders. An 18% PPV threshold discriminated between responders and non-responders to volume expansion, with a sensitivity of 87% (95% CI = 47%-98%) and a specificity of 54% (95% CI = 23%-83%). The area under the receiver operating characteristic curve was 0.72 (95% CI = 0.47-0.90) and was not different from those generated for central venous pressure and pulmonary arterial occlusion pressure. ACC induced a significant increase in PPV and reduced its ability to predict fluid responsiveness.

Therapeutic option for managing lung injury induced by infrarenal aortic cross-clamping

BackgroundOperations on the infrarenal aorta can cause ischemic-reperfusion (IR) injury in local tissues, which could result in remote organ (e.g., lung) damage. Treatment of such injuries remains an unresolved problem. ObjectivesOur aim was to reduce remote lung damage after lower limb IR by means of postconditioning. Materials and methodsMale Wistar rats were divided into three groups: Sham-operated, IR, and Postconditioned (PostC). In the latter two groups rats underwent 180 min of exclusion of the infrarenal aorta. The reperfusion time was 4 h. Serum-free radical levels, tumor necrosis factor-α and interleukin-6 concentrations, histologic changes in the lung, wet/dry-ratio, myeloperoxidase activity, heat shock protein 72 level and blood gas changes were investigated. ResultsPostconditioning reduced histological damage in the lung (P < 0.05). Free radical levels and tumor necrosis factor-α concentrations were significantly lower in the PostC group than in the IR group (P < 0.05 and P < 0.01, respectively). Interleukin-6 concentrations did not significantly differ in the PostC group. Compared with the IR group, lung myeloperoxidase activity was lower in the PostC group. Decreased pulmonary heat shock protein 72 level was observed in the PostC group compared with the IR group and the wet/dry-ratio was also significantly lower in the PostC group (P < 0.05). A noticeably higher arterial pO2 level was manifest in the PostC group after 2 and 4 h of reperfusion (P < 0.05). ConclusionsPostconditioning reduced lung damage under experimental conditions, in the early period of reperfusion after lower limb IR injury.

Descending aortic blood flow during aortic cross-clamp indicates postoperative splanchnic perfusion and gastrointestinal function in patients undergoing aortic reconstruction

The purpose of this observational study was to investigate the relationship between splanchnic and renal blood flow during infrarenal aortic cross-clamp (XC) and postoperative gastrointestinal perfusion and function. Descending aortic blood flow (DABF) was continuously monitored with an oesophageal Doppler monitor (Cardio-Q, Deltex Ltd, Chichester, UK) in 31 patients undergoing elective abdominal aortic aneurysm repair. Cardiac output (CO) was determined by indocyanine green dilution before, during, and after XC. Perioperative gastrointestinal perfusion was assessed by gastric intramucosal pH (pHi, Tonocap, GE Healthcare, Helsinki, Finland). Postoperative gastrointestinal recovery was assessed by the number of postoperative days until the patient successfully resumed solid food intake. The relationship between the mean DABF during XC and gastric pHi after XC release and postoperative gastrointestinal recovery was analysed with Spearman's correlation coefficient. accounted for ∼ 55% of CO during XC and significantly decreased during XC, despite arterial pressure remaining within an optimal range. There were two distinct relationships between DABF during XC and gastric pHi after XC release. Gastric pHi steeply and linearly declined when indexed DABF was below 0.82 litre min(-1) m(-2). Above this critical value, there was no linear relationship between them. The duration of postoperative gastrointestinal dysfunction was inversely correlated with the mean DABF during XC. The best cut-off value of the mean indexed DABF during XC to prevent prolonged gastrointestinal dysfunction was 1.2 litre min(-1) m(-2). Decreased DABF during XC associates splanchnic hypoperfusion after XC release and delayed recovery of gastrointestinal function.

Myocardial depression following declamping of the infrarenal aortic cross-clamp

Reduced cardiac output during cross-clamping of the aorta has been attributed to the increased afterload. A second mechanism involves reperfusion of the ischemic lower torso. The author studied cardiac contractility during and following one hour of infrarenal aortic cross-clamping. Methods: Ultrasonic crystals were implanted on the anterior and posterior aspects of the left ventricle in 11 anesthetized dogs to measure the external minor diameter. A pressure transducer was placed in the left ventricular, and aortic and Swan-Ganz catheters were introduced. The animals were divided into two groups: A Clamp group (n=6) sustaining one hour of infrarenal aortic cross-clamping, and a Control group (n=5) who underwent a sham operator. Hemodynamic data were collected during the one hour of cross-clamping and for the next two hours.

Aortic Compression and Cross Clamping in a Case of Placenta Percreta and Amniotic Fluid Embolism: A Case Report

Amniotic fluid embolism (AFE, also known as anaphylactoid syndrome of pregnancy) at the time of surgery for placenta percreta has been previously reported. We report here a case in which AFE and associated cardiac arrest occurred following a hysterectomy for placenta percreta. In this case, subhepatic manual aortic compression during the cardiac arrest and chest compressions followed by infrarenal aortic cross-clamping during volume infusion and reversal of the coagulopathy were associated with a successful resuscitation and good maternal outcome.

Neuroprotective effects of infliximab in experimental spinal cord ischemic injury

Reactive oxygen species (ROS) have been implicated in the pathogenesis of spinal cord injury after both ischemia–reperfusion (I/R) and trauma. This experimental study was designed to investigate the potential effects of infliximab, an anti-tumor necrosis factor-α agent, on I/R injury of the rabbit spinal cord. Eighteen New Zealand white rabbits were divided into three groups, each consisting of six rabbits: sham (no I/R), I/R, and infliximab (I/R + infliximab). Spinal cord ischemia was induced by applying an infrarenal aortic cross clamp for 30 minutes. At 48 hours after ischemia, animals were functionally evaluated using the Tarlov score. Changes in the spinal cord were observed by measuring tissue levels of malondialdehyde (MDA), glutathione (GSH), advanced oxidation protein products (AOPP), and superoxide dismutase (SOD) and by evaluating hematoxylin–eosin-stained sections. At 48 hours after ischemia, the Tarlov scores in the infliximab group were higher than those of the I/R group, MDA and AOPP levels in the I/R group were significantly higher than those in the sham and infliximab groups ( p < 0.05), and SOD levels in the infliximab group were significantly higher than those in the I/R and sham groups ( p < 0.05). The sham group had higher GSH levels than the infliximab group; however, the difference was not statistically significant ( p > 0.05). Histological examination revealed that the infliximab group had significantly less vascular proliferation, edema, and neuron loss than the I/R group. These results indicate that infliximab may protect the spinal cord against injury in a rabbit I/R model.

Protective Effect of Etomidate on Spinal Cord Ischemia–Reperfusion Injury Induced by Aortic Occlusion in Rabbits

We conducted a randomized controlled study on the neuroprotective effect of a commonly used anesthetic, etomidate, in an ischemia-reperfusion (IR) injury rabbit model. We studied 24 white adult Japanese rabbits at the animal facility at the Medical College of Wuhan University. Rabbits were randomly assigned into a sham-operation group (group I), an IR group (group II), and an etomidate-treated IR group (group III). Rabbits in groups II and III were subjected to 45 min of infrarenal aortic cross-clamping to induce spinal cord ischemia, while group I rabbits received the sham operation as a control. Following an initial single-dose intravenous injection at 0.6 mg/kg 10 min before aortic clamping, etomidate was infused intravenously at 3mg/(kg . hr) in group III rabbits until unclamping, while 0.9% saline was given as the control in group II. Changes in neurological function scores, histopathology, electromyography, malondialdehyde levels, superoxide dismutase activities, and the concentrations of Ca(2+), Mg(2+), Cu(2+), and Zn(2+) ions were measured. Compared with the sham-operation group, group II showed significant IR injury-associated changes in all parameters evaluated (p<0.01), whereas these unfavorable changes were significantly reversed in etomidate-treated animals (p<0.05 or p<0.01). No significant differences were observed between group I and group III animals in all parameters. Etomidate displayed a potent neuroprotective effect against IR-induced spinal cord injuries. We propose that this effect may be associated with the ability of etomidate to enhance the activities of endogenous antioxidants and maintain the ion balance in IR-affected tissues.