Search PubMed⌕ Search

Biomedical subjects

M A Ergin

Publications and source records attributed to M A Ergin.

At least 37 records · Page 2Linked to original sources
PubMed1999

Surgical techniques. Aortic arch and deep hypothermic circulatory arrest: real-life suspended animation.

Surgical reconstruction of the aortic arch is a complex procedure requiring careful preoperative analysis of the pathology and forethought toward surgical approach. Development of surgical techniques has brought dramatic improvement survival and reduction of neurological events associated with these procedures, yet significant morbidity is still encountered. New approaches to the patient with these pathologies include antegrade and retrograde perfusions to the brain. Continued research into physiology of hypothermic circulatory arrest offers the promise of pharmacological protection of the brain during aortic reconstruction and potentially development of therapeutic modalities to treat and limit ischemic brain damage.

Aorta, Thoracic↗
PubMed1999

Thromboelastography-guided transfusion algorithm reduces transfusions in complex cardiac surgery.

UNLABELLED: Transfusion therapy after cardiac surgery is empirically guided, partly due to a lack of specific point-of-care hemostasis monitors. In a randomized, blinded, prospective trial, we studied cardiac surgical patients at moderate to high risk of transfusion. Patients were randomly assigned to either a thromboelastography (TEG)-guided transfusion algorithm (n = 53) or routine transfusion therapy (n = 52) for intervention after cardiopulmonary bypass. Coagulation tests, TEG variables, mediastinal tube drainage, and transfusions were compared at multiple time points. There were no demographic or hemostatic test result differences between groups, and all patients were given prophylactic antifibrinolytic therapy. Intraoperative transfusion rates did not differ, but there were significantly fewer postoperative and total transfusions in the TEG group. The proportion of patients receiving fresh-frozen plasma (FFP) was 4 of 53 in the TEG group compared with 16 of 52 in the control group (P < 0.002). Patients receiving platelets were 7 of 53 in the TEG group compared with 15 of 52 in the control group (P < 0.05). Patients in the TEG group also received less volume of FFP (36 +/- 142 vs 217 +/- 463 mL; P < 0.04). Mediastinal tube drainage was not statistically different 6, 12, or 24 h postoperatively. Point-of-care coagulation monitoring using TEG resulted in fewer transfusions in the postoperative period. We conclude that the reduction in transfusions may have been due to improved hemostasis in these patients who had earlier and specific identification of the hemostasis abnormality and thus received more appropriate intraoperative transfusion therapy. These data support the use of TEG in an algorithm to guide transfusion therapy in complex cardiac surgery. IMPLICATIONS: Transfusion of allogeneic blood products is common during complex cardiac surgical procedures. In a prospective, randomized trial, we compared a transfusion algorithm using point-of-care coagulation testing with routine laboratory testing, and found the algorithm to be effective in reducing transfusion requirements.

Aged↗
PubMed1999

Descending thoracic and thoracoabdominal aneurysm.

The low incidence of permanent spinal cord injury in our most recent cohort (Group II) of patients suggests that serial sacrifice of intersegmental vessels, careful monitoring of spinal cord function are effective in preventing paraplegia after descending thoracic and thoracoabdominal aneurysm operations. Updated anesthetic and postoperative care minimized overall mortality risk. (Ref. 9.)

Aortic Aneurysm, Abdominal↗
PubMed1998

Rate of carriage, serotype distribution and penicillin resistance of Streptococcus pneumoniae in healthy children.

This study was aimed to define the carriage rates for Streptococcus pneumoniae in a given population in Ankara and also to determine the serotypes and penicillin resistance of these strains. Oropharyngeal swabs were taken from a total of 661 children aged between 0-11 years and living in a province of Ankara between January 1995-January 1997. Serotyping was performed by detection of the Quellung reaction. The isolates were screened for penicillin susceptibility by the agar dilution method according to the guidelines of NCCLS. The total rate of pneumococcal carriage in the study population was 23.90% and the isolation rate was found to be statistically associated with age, being higher in small children. Among the 158 S. pneumoniae isolates, the most prevalent serotypes (in order of frequency) were 6, 19, 9, 23, 3 and 14. Penicillin susceptibility was examined in 120 of the isolates. 55 of them (45.83%) were susceptible, 53 (44.17%) were intermediately and 12 (10.0%) were highly resistant to penicillin. Evaluation of the results showed that serotypes 6, 14 and 23 were those most often associated with penicillin resistance. The significant rate of isolation of penicillin-resistant pneumococci in healthy carriers points to the importance of active immunization in risk groups and also the importance of the rational use of antibiotics to limit the spread of resistant strains.

Carrier State↗
PubMed1998

Minimizing spinal cord injury during repair of descending thoracic and thoracoabdominal aneurysms: the Mount Sinai approach.

In an effort to reduce the incidence of spinal cord injury following resection of descending thoracic and thoracoabdominal aneurysms, we have developed a multifaceted approach to maximize spinal cord perfusion which involves monitoring spinal cord function using somatosensory evoked potentials (SSEPs) intraoperatively and postoperatively. Intercostal and lumbar intersegmental vessels are sacrificed in a gradual stepwise fashion before the aneurysm is incised: none of these vessels is reattached unless SSEPs are abnormal following temporary occlusion, and this has not yet been observed. Postoperative spinal cord perfusion is maximized by keeping arterial pressure high and by draining cerebrospinal fluid if intrathecal pressure is elevated. Only two cases of permanent paraplegia have developed in 95 patients. Multivariate analysis showed extensive aneurysms (spanning 10 or more intersegmental arteries) and a history of smoking as the only significant risk factors for development of spinal cord injury.

Aortic Aneurysm, Abdominal↗
PubMed1997

Prospective study of the natural history of thoracic aortic aneurysms.

BACKGROUND: The decision whether or not to recommend resection of moderately large descending thoracic and thoracoabdominal aneurysms requires weighing the relatively high mortality and significant risk of paraplegia associated with operation against the likelihood that the aneurysm will rupture spontaneously, with an almost invariably fatal outcome. To better define the risk of aneurysm rupture, we undertook a prospective study of patients who had not had operation on their moderately large descending thoracic and thoracoabdominal aneurysms. METHODS: Patients were enrolled at the time of their second computed tomographic scans: three-dimensional computer-generated reconstructions allowed determination of several dimensional parameters for each study, including diameters and cross-sectional areas at the site of maximal dilatation in the descending aorta and in the abdomen as well as total thoracoabdominal surface area. Comparisons of serial studies permitted calculation of yearly rates of change in these dimensions. RESULTS: Of 114 patients, 8 died of causes unrelated to the aneurysm, 26 died of rupture, 20 met previously determined criteria for operation, and 60 survived without operation or rupture. Multivariate regression analysis identified maximal diameter in the descending and in the abdominal aorta as independent risk factors for rupture, as well as older age, the presence of even uncharacteristic pain, and a history of chronic obstructive pulmonary disease. A piecewise exponential model enabled construction of an equation allowing calculation of rate of rupture in patients in whom the values of the risk factors are known, and also of the probability of rupture in a given individual over a specified time interval. CONCLUSIONS: Because using this equation--based on easily determined risk factors (age, pain, chronic obstructive pulmonary disease, maximal thoracic and maximal abdominal aortic diameter)--allows the risk of aneurysm rupture within a given interval to be estimated fairly accurately for each individual patient, it is our current practice to recommend operation when the calculated risk of rupture within 1 year exceeds the anticipated mortality of elective operation, rather than relying on general operative guidelines based almost exclusively on aneurysm size.

Adult↗
PubMed1996

Selective management of acute type B aortic dissection: long-term follow-up.

BACKGROUND: Since 1985, we have selectively treated acute type B aortic dissections. Initial treatment lowered blood pressure and heart rate. Transesophageal echocardiography and computed tomographic scans were used to diagnose and follow up the patients. Patients were operated on for organ ischemia, pain, hypertension, or increasing subpleural fluid on computed tomographic scan. METHODS: We retrospectively reviewed consecutive patients admitted over a 10-year period to the Mt. Sinai Hospital. RESULTS: From August 1985 to May 1995, 68 patients were seen. Three died soon after admission during initial diagnostic evaluation. Seventeen patients underwent operation without mortality or paraplegia (group 1). Forty-seven of 48 patients treated nonoperatively were discharged; 1 patient died of rupture on day 7 (group 2). Actuarial survival for all 68 patients at 1 and 5 years was 92% +/- 4% and 82% +/- 8%. Group 1 survival was 93% +/- 4% and 68% +/- 5%, and group 2 survival was 90% +/- 6% and 87% +/-14%. There were no differences between groups. Late intervention was required in 2 group 1 patients (12%) and in 12 of 48 group 2 patients (25%), again without mortality or paraplegia. CONCLUSIONS: This experience suggests that selective management of acute type B aortic dissection results in acceptable short-term and long-term survival. Avoiding early operation did not compromise late results.

Adult↗
PubMed1996

Looking for the artery of Adamkiewicz: a quest to minimize paraplegia after operations for aneurysms of the descending thoracic and thoracoabdominal aorta.

All patients undergoing resection of thoracic or thoracoabdominal aneurysms at Mount Sinai Hospital since November 1993 had spinal cord function monitored with somatosensory-evoked potentials as part of a multimodality approach to reducing spinal cord injury. In the segment to be resected, each pair of intersegmental vessels was sequentially clamped, and they were subsequently sacrificed only if no change in somatosensory evoked potentials occurred within 8 to 10 minutes after occlusion. Adjunctive protective measures included mild hypothermia (31 degrees to 33 degrees C), distal perfusion, corticosteroids, maintenance of high normal blood pressures, avoidance of nitroprusside, and cerebrospinal fluid drainage. Ninety-five consecutive patients operated on since 1993 (group II) were compared with 138 earlier patients (group I). Preoperative characteristics such as age, sex, etiology of aneurysm, emergency operation, and reoperation did not differ between groups, nor did operative variables such as incidence of rupture and extent of resection. Group I had slightly more smokers and slightly fewer hypertensive individuals. Group II patients had a significantly better outcome with respect to in-hospital mortality (10.5% vs 18%, p = 0.045) and paraplegia (2% vs 8%, p = 0.008). By multivariate analysis, rupture and diabetes were associated with significantly higher in-hospital mortality, and smoking greatly increased the incidence of paraplegia. The extent of the aneurysm was a major determinant of mortality and paraplegia. The low paraplegia rate in group II was achieved without reattachment of a single intercostal or lumbar artery. No patient with fewer than 10 intersegmental arteries severed had paraplegia, and spinal cord ischemia was reversible in three patients after adjunctive maneuvers were performed to improve perfusion, suggesting that spinal cord blood supply is unlikely to depend on a single "artery of Adamkiewicz."

Aged↗
PubMed1996

Radical replacement of the aortic root in acute type A dissection: indications and outcome.

OBJECTIVE: Failure of the repair at the proximal aorta is an important cause of morbidity and mortality following surgical treatment of acute type A dissection. This review was undertaken to determine the influence of total composite replacement of the ascending aorta and the root on the operative risk and long-term survival. METHODS: In a consecutive series of 73 patients with acute type A dissections between 1985 and 1994, 19 (26%) patients with radical root replacement (group I) were compared with 54 patients who had conventional valve-preserving root reconstruction (group II). RESULTS: Group I represented a higher operative risk with the presence of significant aortic regurgitation (13/19 68.4% vs 23/54 42.5% P < 0.05), aortic dilatation (19/19 100% vs 32/54 59.2% P < 0.00), and coronary dissection (13/19 68.4% vs 3/54 5.5% P < 0.000). In spite of this there was no difference in operative mortality (3/19 15.7% vs 7/54 12.9%, NS) or the occurrence of major postoperative complications: bleeding (3/19 15.7% vs 7/54 12.9%, NS), respiratory (5/19 26.3% vs 11/54 20.3%, NS), stroke (2/19 10.5% vs 3/54 5.5%, NS). Patients with radical root replacement had substantially better event-free survival at 5 years (87.5% +/- 11.7% vs 67.1% +/- 8.9%) and 9 years (87.5% +/- 21.9% vs 63.0% +/- 19.2%). CONCLUSIONS: This experience confirms that, in the treatment of acute type A dissection, an aggressive approach to aortic root pathology is indicated for specific indications, and can be carried out with good early and excellent long-term results.

Adult↗
PubMed1996

Tranexamic acid reduces transfusions and mediastinal drainage in repeat cardiac surgery.

The administration of tranexamic acid (TA) prior to cardiopulmonary bypass (CPB) has been associated with reduced bleeding during and after cardiac surgery. In a prospective, randomized, controlled, double-blind clinical trial, adult patients undergoing repeat open heart surgery received TA (n = 17) or an equal volume of saline placebo (n = 13). In the TA group, a 20-mg/kg intravenous (IV) initial dose of TA at akin incision was followed by an infusion of 2 mg.kg-1.h-1, which continued for the duration of the surgical procedure. Identical transfusion guidelines were followed in both groups. Routine coagulation tests, D-dimer levels, mediastinal tube drainage, and transfusion requirements were compared. Cumulative postoperative mediastinal tube drainage measured at 24 h was 649 +/- 391 mliter (mean +/- SD) in the TA group compared with 923 +/- 496 mliter in the placebo group (P < 0.01). Forty-eight-and 72-h mediastinal tube drainage were also significantly less in the TA group (P < 0.01). Seven of 17 TA patients received to transfusion of allogeneic blood products compared with 1 of 13 placebo patients (P = 0.047). The incidence and volumes of platelet and fresh frozen plasma transfusion in the TA group were not significantly different in comparison with the placebo group. The perioperative increase in D-dimer levels (post-CPB minus pre-CPB) in the placebo group (median difference = 675 ng/mliter, range 125-1648) was significantly more than in the TA group (median difference = 182 ng/mliter, range -426-1950; P = 0.003). Sternal closure occurred in 41 +/- 21 min in the TA group and 61 +/- 49 min in the placebo group (P = 0.14), and the subjective bleeding score was less in the TA group than in the placebo group (2.38 +/- 0.78 vs 3.08 +/- 1.04; P = 0.045). The data from the current study support the prophylactic use of TA in patients undergoing repeat cardiac surgery. TA administered prior to CPB reduced the incidence of allogeneic transfusions and postoperative mediastinal tube drainage, and improved the subjective assessment of post-CPB hemostasis in a group of patients at moderately high risk for perioperative bleeding.

Adult↗
PubMed1995

Surgical techniques in prosthetic valve endocarditis.

Annular extension of the infectious process is common in prosthetic valve endocarditis and carries a substantial prognostic significance in determining the immediate and late results of the surgical treatment of prosthetic valve endocarditis. Advanced destruction of the annular tissues requires complex reparative techniques for treatment. The cardiac surgeon faces the challenge of removing all infected tissues while preserving and restoring the functional integrity of the ventricular inlet and outlet. Familiarity with a growing number of specialized techniques is necessary for effective surgical treatment of these destructive lesions. This article is a synopsis of surgical techniques that we have found useful in the treatment of extensive annular destruction in bacterial endocarditis.

Endocarditis, Bacterial↗
PubMed1994

Significance of distal false lumen after type A dissection repair.

Fifty-eight patients underwent repair of acute type A dissection between 1986 and 1992. Follow-up aortogram, computed tomographic scan with contrast, magnetic resonance imaging scan, or a combination of these tests was available in 38 patients with preoperatively patent distal false lumens. All distal anastomoses were constructed with the open technique during a period of circulatory arrest. There were 25 suture and 13 intraluminal graft anastomoses. Patency of the distal false lumen was found in 47.3%. Use of the intraluminal graft for the distal anastomosis decreased patency, although not significantly (4/13, 30% versus 14/25, 56%; p = 0.14). The direction of flow into the false lumen was antegrade in 11 of 24 (45.8%) of sutured anastomoses and 0 of 9 intraluminal graft anastomoses (p < 0.01). Actuarial survival at 5 years for patients with closed distal false lumen was 95% +/- 4.8% versus 76% +/- 15% for patients with patency of the distal false lumen (p = not significant). Event-free survival at 5 years for both groups was 84% +/- 8.3% (closed false lumen) and 63% +/- 13.5% (patency of distal false lumen; p = not significant). This experience indicates that in the treatment of acute type A dissections, operative strategy and anastomotic technique play a role in reducing the incidence of patency and related complications of the distal false lumen.

Actuarial Analysis↗
PubMed1994

Pathogenesis of spinal cord injury during simulated aneurysm repair in a chronic animal model.

The pathogenesis of paraplegia after repair of thoracic aortic aneurysms is controversial. Using direct spinal cord evoked potential monitoring, critical intercostal arteries (CICA) were identified to evaluate the impact of backbleeding and ligation versus that of preservation during simulated aneurysm repair. Thirty pigs (40 kg) were randomly assigned to one of five groups. In groups 1 through 4, a thoracic segment containing CICA was cross-clamped for 60 minutes and distal aortic perfusion was provided by a centrifugal pump. In groups 1 and 2, the thoracic segment was vented, maintaining segment pressure at 0 mm Hg; CICA were ligated in group 1 and preserved in group 2. Thoracic segment was perfused at 70 mm Hg in groups 3 and 4; CICA were ligated in group 3 and preserved in group 4. Critical intercostal artery ligations were performed at the end of the cross-clamp period. In group 5 simple cross-clamping at the left subclavian artery was performed as a control. The combination of venting and ligation of CICA correlated with impaired neurologic outcome according to Tarlov's score (median, 1.5 in group 1 versus 3 in group 2; p = 0.015), indicated by a significant difference in median values of direct spinal cord evoked potential amplitude (expressed as a fraction of baseline values) at 120 minutes after cross-clamping (0.76 in group 1 versus 0.98 in group 2; p = 0.0082).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Hypothermic circulatory arrest and other methods of cerebral protection during operations on the thoracic aorta.

Current surgical techniques in operations on the thoracic aorta frequently require exclusion of the cerebral circulation for varying periods. During these periods, hypothermic circulatory arrest (HCA), selective cerebral perfusion (SCP), and retrograde cerebral perfusion (RCP) can be used for cerebral protection. Hypothermia is the principle component of these methods of protection. The main protective effect of hypothermia is based on reduction of cerebral energy expenditures and largely depends on adequate suppression of cerebral function. It is most effective at deep hypothermic levels (13 degrees C to 15 degrees C). Measures that preserve autoregulation of cerebral blood flow help increase the margin of safety with all methods of protection. There is solid experimental and clinical data indicating the safe limits and outcome following HCA. Current applications of SCP and RCP are fairly recent developments and do not have comparable supporting data. SCP can be used without deep hypothermia and allows prolonged periods of cerebral protection, but is complex in application. RCP is simpler, but always requires deep hypothermia. Present clinical data do not allow separation of its protective effect from that of HCA alone. Recent modifications in the application of HCA include monitoring of cerebral O2 extraction, and selective use of supplemental SCP to limit arrest times to less than 50 minutes, or RCP to prevent embolic strokes, as indicated. These changes appear to have reduced the overall mortality, the severity of embolic strokes, and stroke-related mortality.

Adult↗
PubMed1994

Comparison of retrograde cerebral perfusion to antegrade cerebral perfusion and hypothermic circulatory arrest in a chronic porcine model.

Retrograde cerebral perfusion (RCP) is a new method of cerebral protection that has been touted as an improvement over hypothermic circulatory arrest (HCA). However, RCP has been used clinically for durations and at temperatures that are "safe" for HCA alone. This study was designed to compare RCP to HCA and antegrade cerebral perfusion (ACP) deliberately exceeding "safe" limits, in order to determine unequivocally whether RCP provides better cerebral protection than HCA. Four groups of six Yorkshire pigs (20 to 30 kg) were randomly assigned to undergo 90 minutes of RCP, ACP, HCA, or HCA with heads packed in ice (HCA-HP) at an esophageal temperature of 20 degrees C. Arterial, mixed venous and cerebral venous oxygen, glucose and lactate contents; quantitative EEG; were monitored at baseline (37 degrees C); at the end of cooling cardiopulmonary bypass (20 degrees C); during rewarming (30 degrees C); and at two and four hours post intervention. Animals were recovered and were evaluated daily using a quantitative behavioral score (0 to 9). Mean behavioral score was lower in the HCA group than in the other three groups at seven days (HCA 5.8 +/- 1.1; RCP 8.5 +/- 0.2; ACP 9.0 +/- 0.0; HCA-HP 8.5 +/- 0.2, p < 0.05). Recovery of QEEG was better in the ACP group than in all others, but the RCP group had faster EEG recovery than HCA alone, although not better than HCA-HP (HCA 15 +/- 4; RCP 27 +/- 3; ACP 78 +/- 5; HCA-HP 19 +/- 3, p < 0.001). However, histopathological evidence of ischemic injury was present in 5 of 6 HCA animals and also in 4 of 6 of the HCP-HP group, but only in 1 of 6 RCP animals and in none of the ACP group. This study demonstrates that ACP affords the best cerebral protection by all outcome measures, but RCP provides clear improvement compared to HCA.

Animals↗
PubMed1994

A new technique using somatosensory evoked potential guidance during descending and thoracoabdominal aortic repairs.

Recent work in our laboratory has demonstrated the effectiveness of somatosensory evoked potentials (SEPs) in identifying the critical intercostal arteries (CICAs) for preserving spinal cord integrity during simulated aortic aneurysm repairs in the pig. Further studies have also demonstrated increased preservation of neurological function during prolonged aortic clamping if CICAs are perfused until ligation or clipping, as opposed to transaortic identification of back-bleeding intercostals and their subsequent ligation. We have developed a technique of repair of descending thoracic and thoracoabdominal aortic aneurysms and dissections that uses these principles. Since January 1993, 26 patients have undergone repair of their aortas using this new technique and SEP directed intercostal artery ablation. There were 22 (85%) long-term survivors among 10 thoracoabdominal and 16 descending aortic repairs. All patients with uncorrected abnormal SEP recordings developed paralysis; one patient who required reimplantation of an intercostal artery island into the aortic graft had normal neurological function postoperatively. Paraplegia was seen in only one of the surviving patients, but this patient had normal intra- and postoperative SEPs (4% false negative). Our experience suggests that SEP-guided obliteration of intercostal arteries while maintaining perfusion may be a useful approach to the surgical repair of descending and thoracoabdominal aortic disease.

Adolescent↗