Biomedical subjects

Selami Dogan

Publications and source records attributed to Selami Dogan.

29 records · Page 2Linked to original sources

PubMed2003

Totally endoscopic atrial septal repair in adults with computer-enhanced telemanipulation.

OBJECTIVE: Standard surgical closure of an atrial septal defect via sternotomy is a safe and effective procedure with low morbidity and mortality. Considering that young female patients are frequently operated on for atrial septal defects, a minimally invasive procedure avoiding sternotomy is convincingly desirable and led to the approach through a right anterolateral minithoracotomy. The recent clinical introduction of robotically assisted surgery further reduced skin incisions and enabled totally endoscopic procedures through ports. This article reports on a first series of atrial septal defect closures of which the first case was operated on August 24, 1999, in a totally endoscopic closed chest technique using a computer-enhanced telemanipulation system. METHODS: We performed totally endoscopic atrial septal repair using the da Vinci surgical system (Intuitive Surgical, Mountain View, Calif) in 10 consecutive adult patients. Median age was 45.5 +/- 10.0 years, and preoperative New York Heart Association functional class was 1.8 +/- 0.1. Left ventricular ejection fraction was normal in all patients and mean pulmonary artery pressure amounted to 35 +/- 7 mm Hg. Shunt volume ranged from 24% to 70%. All patients displayed a fossa ovalis type of atrial septal defect; 2 of them multiperforated. RESULTS: Neither intraoperative nor postoperative complications occurred. Two patients had to be converted to minithoracotomy due to endoaortic balloon clamp failure. Length of operation was 262 +/- 37 minutes, and cardiopulmonary bypass time was 161 +/- 26 minutes. Intraoperative transesophageal echocardiography certified complete closure of the atrial septal defect in all patients. The totally endoscopic computer-enhanced technique yielded excellent cosmetic results. CONCLUSION: Totally endoscopic atrial septal repair is a feasible and safe procedure with good clinical results and excellent cosmetic outcomes. It may be considered as perfect adjunct to interventional treatment options. Further studies with larger cohorts and randomized trials are necessary to document potential benefits. Evolution in robotic technology and refinement of procedural flow may shorten procedural time and decrease costs.

Adult↗

PubMed2003

Multi-detector row CT versus coronary angiography: preoperative evaluation before totally endoscopic coronary artery bypass grafting.

PURPOSE: To assess multi-detector row spiral computed tomography (CT) for preoperative evaluation of patients undergoing totally endoscopic coronary artery bypass grafting and to correlate the data with coronary angiographic and intraoperative findings. MATERIALS AND METHODS: Thirty-six patients preoperatively underwent multi-detector row CT (4 x 1-mm collimation, pitch of 1.5, 500-msec rotation time, retrospective electrocardiographic gating, 1.25-mm effective section thickness) and coronary angiography. Assessment criteria for both techniques were visibility and cardiac course of coronary arteries, localization and degree of stenoses, composition of atherosclerotic plaques, and vascular diameter at anastomosis site. Site for distal bypass anastomosis was recommended. Results at multi-detector row CT were calculated relative to results at coronary angiography and surgery. RESULTS: Multi-detector row CT properly displayed 79.4% (154 of 194) of all surgical relevant coronary segments and 80.4% (434 of 540) of all coronary segments. For coronary angiography, ratios of 88.7% (172 of 194) and 94.6% (511 of 540), respectively, were observed. For detection of calcified plaques, multi-detector row CT results exceeded those at coronary angiography by a difference of 17% (18 of 18 [100%] compared with 15 of 18 [83%]). Hemodynamically relevant stenoses were identified with multi-detector row CT in 76% (42 of 55) of cases. Bridging of coronary segments through either myocardium (four of five) or epicardial fat (two of three) was better identified at multi-detector row CT than it was at coronary angiography (one of five compared with zero of three, respectively). At multi-detector row CT, 76% (28 of 37) of all distal bypass touchdown segments were identified, but at coronary angiography, only 70% (26 of 37) were identified. CONCLUSION: Multi-detector row CT provides extended information about coronary target site and therefore should be regarded as an ideal additive planning tool for complex minimally invasive procedures such as totally endoscopic coronary artery bypass grafting or minimally invasive direct coronary artery bypass grafting.

Adult↗

PubMed2003

Minimally invasive versus conventional aortic valve replacement: a prospective randomized trial.

BACKGROUND AND AIM OF THE STUDY: A prospective randomized study was performed to compare conventional with minimally invasive aortic valve replacement (AVR). METHODS: Forty consecutive patients scheduled for elective aortic valve surgery were prospectively randomized either to the conventional group (group A, complete median sternotomy) or minimally invasive group (group B, partial upper sternotomy). Intraoperative and postoperative clinical data, and markers of myocardial and cerebral protection were determined. Neuropsychological tests were carried out to quantify psychological disorders. RESULTS: Operative time and cardiopulmonary bypass time were slightly longer in group B, but not significantly so. No significant inter-group differences were found for postoperative pain scores and respiratory function. Chest tube drainage was significantly less in group B (495 +/- 165 versus 240 +/- 69 ml, p = 0.008). Creatine kinase (CK), CK-MB and troponin T levels were similar in both groups. Neither S-100B protein nor neuron-specific enolase levels differed significantly between groups at all sampling times. There were no strokes in the entire cohort. None of the neuropsychological tests yielded significant inter-group differences between conventional and minimally invasive surgery. CONCLUSION: The safety and reliability of AVR via a partial upper sternotomy is reported. Minimally invasive AVR can be performed with only slightly longer operative times, good cosmetic results and significantly less blood loss. A limited surgical access affected neither the patients' neurological outcome nor the efficacy of myocardial protection.

Aortic Valve Insufficiency↗

PubMed2002

Heart-rate-adapted image reconstruction in multidetector-row cardiac CT: influence of physiological and technical prerequisite on image quality.

The purpose of this study was to develop strategies for optimal image reconstruction in multidetector-row cardiac CT and to discuss the results in the context of individual heart rate, cardiac physiology, and technical prerequisite. Sixty-four patients underwent multidetector-row cardiac CT. Depending on the heart rate either a single-segmental reconstruction (SSR) or an adaptive two-segmental reconstruction (ASR) was applied. Image reconstruction was done either antegrade (a) or retrograde (r) in relation to the R-peak. Reconstruction of all data sets was performed at multiple time points within the t-wave/p-wave interval, differing from each other by 50 ms. In addition, each reconstruction was assigned to one of six reconstruction intervals (A-F), each corresponding to a specific event in the cardiac cycle. While no significant time points were found for absolute values, the following interval/reconstruction technique combinations provided significant better image quality: F/r at HR <60 bpm for all coronary segments ( p</=0.004) and at HR 60-65 bpm for segments 5-10 ( p</=0.001); B/a at HR 60-65 bpm for segments 1-4 and 11-15 ( p<0.001) and at HR >65 bpm for all segments ( p</=0.002). The results show that in order to achieve optimal image quality, image reconstruction has to be adjusted to each patient's ECG curve and heart rate individually. The moment of reconstruction should be determined as absolute rather than as relative distance from the previous R-peak.

Algorithms↗

PubMed2002

How safe is the port access technique in minimally invasive coronary artery bypass grafting?

BACKGROUND: This study compares conventional coronary artery bypass grafting (CABG) with port access CABG via a left anterior small thoracotomy in patients requiring surgical multivessel revascularization. Clinical, neuropsychological, and angiographic outcomes were studied, as well as parameters of myocardial and cerebral protection. Pathogenicity of cardiopulmonary bypass (CPB) was further evaluated by measuring parameters of peripheral limb ischemia and inflammatory whole-body response. METHODS: In a prospective randomized study, 40 patients who required multivessel CABG were assigned to either conventional CABG via complete median sternotomy (group A) or port access CABG via minithoracotomy (group B). Control angiograms were performed in group B only. In addition, patients underwent neuropsychological testing after the operation. CK, CK-MB, and Troponin T levels were documented. S-100B protein and neuron-specific enolase (NSE) served to quantify cerebral injury. The terminal complement complex (C5b-9) and myeloperoxidase concentrations were determined to analyze inflammatory whole-body response after CPB. RESULTS: There was no mortality. One patient suffered a retrograde aortic dissection immediately after onset of CPB, but had an uneventful postoperative course after surgical repair. Troponin T and CK-MB showed no difference between groups. CK and myoglobin were significantly higher in the minimally invasive cohort. Changes in complement activation (C5b-9) and myeloperoxidase during CPB markers of the whole-body inflammatory response were similar in both groups. S-100B concentrations in the port access group were significantly higher, whereas NSE levels were similar in both groups. Both groups did not display any significant difference in neuropsychological testing. CONCLUSIONS: Minimally invasive multivessel CABG via minithoracotomy using port access technology is feasible and safe. Though prolonged operating and CPB times with significantly higher S-100B concentrations were observed in group B, equivalent myocardial and cerebral protection and similar whole-body inflammatory response were documented.

Aged↗

PubMed2002

Robotically enhanced placement of left ventricular epicardial electrodes during implantation of a biventricular implantable cardioverter defibrillator system.

Biventricular pacing has gained increasing acceptance in advanced heart failure patients. One major limitation of this therapy is positioning the left ventricular stimulation lead via the coronary sinus. This report demonstrates the feasibility of totally endoscopic direct placement of an epicardial stimulation lead on the left ventricle using the daVinci surgical system.

Aged↗

PubMed2002

Segmental wall motion abnormalities during telerobotic totally endoscopic coronary artery bypass grafting.

UNLABELLED: In addition to single-lung ventilation (SLV), intrathoracic CO2 insufflation is mandatory for adequate exposure during totally endoscopic coronary artery bypass grafting. With transesophageal echocardiography, we investigated biventricular myocardial wall motion in 25 patients with isolated disease of the left anterior descending coronary artery who underwent totally endoscopic coronary artery bypass grafting with the "Da Vinci" robotic surgical system. At distinct time points during the operation, a cine loop of both ventricles was registered from a transgastric mid-short-axis view. Myocardial wall motion analysis was performed according to an established segmentation model of the left ventricle and to an established five-point scale for wall motion (1, normal; 5, dyskinesia). Significant alterations from preoperative baseline wall motion were visible in the septal, inferior, and anterior segments of the left ventricle at some time during the prebypass period, combined with a markedly decreased PaO2 under SLV and increased intrathoracic pressure. The same findings applied to the right ventricle; however, wall motion abnormalities were more pronounced here. After myocardial revascularization, weaning from cardiopulmonary bypass, CO2 deflation, and return to double-lung ventilation, myocardial wall motion recovered to baseline values. Clinically significant hemodynamic instability did not occur. The data suggest that robot-assisted coronary artery bypass grafting leads to significant prebypass alterations of biventricular segmental wall motion. On the basis of our data, it cannot be definitively stated whether the observed results were due to reduced oxygenation during SLV and thus "real" myocardial ischemia, intrathoracic CO2 insufflation with positive pressure leading to mechanical compromise of the heart, absolute or relative hypovolemia, or a combination of these factors. However, in this cohort, which consisted of patients with single-vessel disease and good ventricular function, these changes were of limited clinical relevance. IMPLICATIONS: Segmental myocardial wall motion was evaluated with transesophageal echocardiography during robot-assisted totally endoscopic coronary artery bypass grafting. Significant biventricular segmental wall motion abnormalities occurred before cardiopulmonary bypass under single-lung ventilation and carbon dioxide insufflation. The changes in myocardial wall motion were of limited clinical relevance.

Carbon Dioxide↗

PubMed2002

High thoracic epidural anesthesia for coronary artery bypass grafting using two different surgical approaches in conscious patients.

Recent developments in coronary artery bypass graft surgery (CABG) without cardiopulmonary bypass made the sole use of high thoracic epidural anesthesia (TEA) in conscious patients feasible. Previously, TEA has been reported only for single-vessel CABG via lateral thoracotomy. We investigated the feasibility and complications of sole TEA in 20 patients undergoing beating-heart arterial revascularization via partial lower sternotomy for single-vessel disease (minimally invasive direct coronary artery bypass grafting [MIDCAB] technique; n = 10) or complete median sternotomy for multivessel disease (off-pump coronary artery bypass grafting [OPCAB] technique; n = 10). An epidural catheter was inserted at the T1-2 or T2-3 interspace. An epidural infusion of ropivacaine 0.5% and sufentanil 1.66 micro g/mL was started to establish anesthetic levels at C5-6 for OPCAB and at T1-2 for MIDCAB. Nine OPCAB and eight MIDCAB procedures were completed while patients were awake and spontaneously breathing during the entire procedure. Because of surgical pneumothorax (OPCAB), insufficient anesthesia, or phrenic nerve palsy (both MIDCAB), three patients required intraoperative conversion to general anesthesia. The heart rate decreased significantly (P < 0.05) by 10%-15% in both groups during the procedure. Compared with baseline (B), mean arterial blood pressure (mm Hg) was decreased significantly only during coronary anastomosis (CA) (B(OPCAB), 95 +/- 11; CA(OPCAB), 68 +/- 9; B(MIDCAB), 86 +/- 10; CA(MIDCAB), 73 +/- 10; P not significant between groups). PaCO(2) increased from 42 +/- 2 mm Hg to 46 +/- 7 mm Hg (P < 0.05) throughout the perioperative course during OPCAB, whereas it remained almost unaltered during MIDCAB procedures. All patients rated TEA as "good" or "excellent." In conclusion, we demonstrated that the sole use of TEA for MIDCAB and OPCAB procedures was feasible and provided a high degree of patient satisfaction in our small and highly selected cohorts. IMPLICATIONS. The sole use of high thoracic epidural anesthesia was studied in 20 patients who underwent beating-heart coronary artery bypass grafting using either median or partial lower sternotomy while awake.

Aged↗

PubMed2002

Techniques for the detection of coronary atherosclerosis: multi-detector row CT coronary angiography.

PURPOSE: To investigate the accuracy of different computed tomographic (CT) reformation techniques in assessing the coronary arteries. MATERIALS AND METHODS: Sixty-four patients undergoing both multi-detector row CT and invasive coronary angiography were consecutively included in a retrospective study. CT scans were obtained with collimation of 4 x 1 mm, pitch of 1.5, and rotation time of 500 msec. Retrospective electrocardiographic gating was used for image reconstruction, with 1.25-mm section thickness and 0.5-mm increment. The CT data set of each patient was evaluated by independent observers using transverse scanning, virtual endoscopic, and three-dimensional reformation and multiplanar reformation. RESULTS: Hemodynamically relevant stenoses (>50%) were detected with highest sensitivity at transverse scanning (58 of 79 [73.4%] stenoses), followed by virtual endoscopic (38 of 79 [48.1%] stenoses) and three-dimensional reformation (34 of 79 [43.0%] stenoses), and multiplanar reformation (37 of 79 [46.8%] stenoses). Atherosclerotic plaques were identified with comparable sensitivities at transverse scanning (143 of 218 plaques [65.6%]) and at three-dimensional (139 of 218 [63.8%] plaques) and virtual endoscopic reformation (136 of 218 [62.4%] plaques). Multiplanar reformation had distinctly poorer results (217 of 218 [58.3%] plaques). Combined interpretation with all four techniques increased sensitivity to 74.7% (59 of 79) for stenosis and 71.6% (156 of 218) for atherosclerosis. Calculated overall specificity was 91.4% or greater. Sufficient vascular evaluation was possible only in vessels larger than 1.6 mm in diameter. Thus, even in patients with heart rates below 60 bpm, only 80.0% of all coronary segments could be visualized, while at higher frequencies, visibility decreased to 66.2%. CONCLUSION: Although multi-detector row CT is a favorable alternative procedure in evaluating coronary arteries, its clinical value still is restricted to low heart rates and proximal coronary arterial segments.

Aged↗

PubMed2002

Coronary artery bypass grafting through complete sternotomy in conscious patients.

BACKGROUND: Complete sternotomy is the standard approach in cardiac surgery, and coronary artery bypass grafting (CABG) is the most common revascularization procedure to use this approach. A new technique has been developed that permits complete surgical revascularization with arterial grafts in awake patients. This technique, which we refer to as awake coronary artery bypass grafting, avoids general anesthesia, mechanical ventilation, and extracorporeal circulation, thereby creating the least invasive method for heart operations yet described. METHODS: A thoracic epidural catheter was placed at T2-T3 level one day before surgery. In 12 patients, single (n = 6), double (n = 5), or triple (n = 1) vessel coronary artery bypass grafting was performed without general anesthesia. In six patients, this procedure was performed after complete median sternotomy. RESULTS: Ten patients remained awake throughout the whole procedure. Two patients required secondary intubation due to incomplete analgesia in one case and pneumothorax in the other. Procedural time was 98.2 +/- 19.8 minutes. Intermediate care stay was 4.9 +/- 0.6 hours. There were no perioperative complications, and early angiographic results before discharge were excellent in all patients. CONCLUSIONS: The data presented show the feasibility and safety of complete surgical revascularization via median sternotomy using arterial grafts without general anesthesia. This approach shortens recovery time and increases patient comfort, suggesting that outpatient cardiac surgery may eventually be possible.

Aged↗

PubMed2002

Totally endoscopic bilateral internal thoracic artery bypass grafting in a young diabetic patient.

BACKGROUND: The introduction of robotics into cardiosurgical practice in 1998 has enabled totally endoscopic closed chest procedures. Totally endoscopic grafting of the LAD (TECAB) is no longer an experimental procedure. CASE REPORT: We report on a case with totally endoscopic bilateral internal thoracic artery bypass grafting to the left anterior descending and right coronary artery in a 36-year-old obese female diabetic patient using the daVinci surgical system. The patient, suffering from juvenile diabetes for 26 years, presented with stable angina (CCS class II). A coronary angiogram revealed 2-vessel disease with a long complex proximal lesion of the left anterior descending artery (LAD) (90%) and 80% stenosis of the proximal right coronary artery (RCA). Due to the condition of the proximal LAD (high risk PTCA with rather poor prognosis), the patient was referred for minimally invasive operative revascularisation of the LAD and the RCA. After informed consent was obtained the patient underwent totally endoscopic double internal thoracic artery bypass revascularisation on the arrested heart using computer-enhanced telemanipulation technology. RESULTS: The feasibility and safety of successful closed chest, totally endoscopic double coronary bypass grafting with two internal thoracic arteries is demonstrated in this case. Preservation of a stable chest cavity and reduced risk for wound healing complications in diabetics with an excellent cosmetic result are the obvious advantages of the techniques described.

Adult↗