Artificial chordae for mitral valve repair: mid-term clinical and echocardiographic results

BACKGROUND

This paper reports on the mid-term clinical and echocardiographic results of mitral valve repair with chordal replacement.

METHODS

Sixty-nine patients (mean age 61 +/- 14 years) underwent mitral valve repair with chordal replacement. The etiology was degenerative in 53 (77 %), rheumatic in 7 (10 %), ischemic in 6 (9 %) and infective in 3 (4 %). Mean ejection fraction was 58 +/- 14. In 35 patients (51 %), a minimally invasive approach was used. Mean follow-up time was 45 +/- 27 months.

RESULTS

Anterior leaflet chordae were replaced in 58 (84 %) patients. There were 3 operative deaths. Freedom from non-trivial recurrent mitral regurgitation (MR) was 81.3 +/- 8.7 % at 97 months. Follow-up echocardiographic controls showed mild recurrent MR in 5 (8 %) patients and moderate in 2 (3.2 %). These two patients required reoperation due to mitral annulus redilation after suture annuloplasty. Competent neochordae were found at reoperation. Freedom from reoperation at 97 months was 96.6 +/- 2.4 %. Four patients died during follow-up resulting in an actuarial survival of 87 +/- 6.2 %.

CONCLUSION

The replacement of chordae tendineae with ePTFE sutures during mitral valve repair has shown good mid-term results. The implantation of the neochordae can be also performed safely using minimally invasive procedures.

Radiographic evaluation of third molar development in relation to chronological age among Turkish children and youth

A sharp increase in forensic age estimation of living persons has been observed in recent years. However, ethnic populations residing in different countries have been insufficiently analyzed. According to 2004 data compiled by the Essen-based Turkey Research Center, there are 3.8 million Turkish people living abroad, and 3.2 million of them reside in European Union countries. Despite the high number of Turks living abroad, little is known about third-molar development for forensic application in this population. Hence, it was considered worthwhile to determine the developmental stages of the third molar in a group of Turkish population, to assess chronological age estimation based on the developmental stages, and to compare third molar development according to sex, age and location. Orthopantomograms of 1134 Turkish patients, ages 4-20 years were examined and third-molar developmental stages were evaluated based on Demirjian's classifications. Orthopantomograms were scored by two different observers, and Wilcoxon matched-pairs signed-ranks test used to test intra- and inter-observer reliability revealed a strong agreement between both intra- and inter-observer measurements. Linear regression analysis was performed to correlate third-molar development and chronological age, and further statistical analysis was performed to determine the relation between sex, age and location. Results showed a strong linear correlation between age and molar development (males: r(2)=0.57; females: r(2)=0.56). Mineralizations of left and right third molars were compared using Wilcoxon tests, and no statistical differences were found. No significant differences were found in third-molar development between males and females. Mandibular third molar crypt formation was observed in 2.4% of patients at age seven and maxillary third molar crypt formation was observed in 1.3% of patients at age seven. A strong correlation was found between third-molar development and chronological age. Among the Turkish population, third molar crypt formation is observable at as early as 7 years in both the mandible and maxilla. Agenesis can be determined conclusively if no radiolucent bud is present by age 14.

Tau protein as a serum marker of brain damage in mild traumatic brain injury: preliminary results

The objective of this study was to investigate the diagnostic value of serum tau protein in determining the severity of traumatic brain injury in patients with mild traumatic brain injury (mTBI) and high-risk patients. Adult patients who presented to our emergency department (ED) with mTBI over 1 year were prospectively enrolled. Patients underwent cranial computed tomography (CT) and were subdivided into high- and low-risk groups, according to the probability of resultant intracranial injury. Serum tau levels of 60 patients and 20 healthy volunteers, who served as a control group, were measured. The mean age of the 60 patients (45 males, 15 females) was 32.5 years (range, 15-66 y). Mean Glasgow Coma Scale (GCS) score was 14+/-0.6. CT scans demonstrated intracranial injury in 11 patients (18.3%) and depressed fracture in 4 patients (6.7%). Serum tau levels of patients (188+/-210 pg/mL), compared with those of controls (86+/-48 pg/mL), were relatively higher; however, differences were not statistically significant (P=.445). Also, serum tau levels of high-risk patients (307+/-246 pg/mL) were significantly higher than those of low-risk patients (77+/-61 pg/mL) (P=.001). A total of 48 patients (80%) were accessible for follow-up after 6 months. Postconcussive syndrome was observed in 8 patients, 5 of whom had serum tau protein levels that were higher than those of the other 3 patients. However, no statistically significant difference was observed (P>.05). Investigators of the present study noted that serum tau levels in patients with mTBI were increased. Therefore, it is believed that this biomarker may prove helpful in identifying high-risk patients with mTBI. However, additional studies are needed to establish the diagnostic value of serum tau in detecting traumatic brain injury in patients with mTBI.

Traumatic epidural haematomas of nonarterial origin: analysis of 30 consecutive cases

BACKGROUND

The purpose was to analyse the clinical and radiological findings, and management approaches used in 30 consecutive cases of traumatic epidural haematoma of nonarterial origin treated at one centre.

METHOD

Medical records for 30 patients surgically treated for epidural haematoma of nonarterial origin between 1997 and 2003 were reviewed. Epidural haematoma of nonarterial origin was diagnosed based on computed tomography (CT) and the bleeding source was confirmed intra-operatively. Admission status, outcome, fracture location, haematoma location/size/volume, and additional intracranial pathology were among the data noted. Two groups were formed for analysis: venous sinus bleeding (group 1) and other venous sources (group 2).

FINDINGS

The 30 cases accounted for 25% of the total number of traumatic epidural haematomas (n = 120) treated during the same period. The epidural haematomas of nonarterial origin locations were transverse sigmoid sinus (n = 11; 36.7%), superior sagittal sinus (n = 6; 20%), venous lakes (n = 5; 16.6%), diploë (n = 5; 0.16%), arachnoid granulations (n = 2; 6.7%), petrosal sinus (n = 1; 3.3%). There were 12 postoperative complications in 9 patients: recurrence (n = 4; 13.3% of the 30 total), pneumonia (n = 4; 13.3%), meningitis (n = 2; 6.7%), hydrocephalus (n = 1; 3.3%) and subdural effusion (n = 1; 3.3%). All recurrence cases were re-explored. Six (20%) patients died. Glasgow Outcome Scale (GOS) scores (mean follow-up 13.3 +/- 7.8 months) revealed 22 (73.3%) patients with favourable results (GOS 4-5) and 8 (26.7%) had poor results (GOS 1-3).

CONCLUSIONS

Cases of epidural haematoma of nonarterial origin differ from the more common arterial-origin epidural haematomas with respect to lesion location, surgical planning, postoperative complications, and outcome. Epidural haematoma of nonarterial origin should be suspected if preoperative CT shows a haematoma overlying a dural venous sinus or in the posterior fossa and convexity. The sinus-origin group had a high frequency of fractures which crossed the sinuses, and this might be diagnostically and surgically useful in such cases.

Gastrointestinal involvement in POEMS syndrome: a novel clinical manifestation

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) is characterised by a rare multisystem disorder of unknown pathogenesis. Although its pathophysiology is not well understood, overexpression of proinflammatory cytokines has been implicated. Gastrointestinal system disorders have not been reported among the components of the syndrome. A case is reported of POEMS syndrome with gastrointestinal involvement shown by gastrointestinal endoscopy.

Oxidised regenerated cellulose as a cause of paraplegia after thoracotomy: case report and review of the literature

STUDY DESIGN

Case report.

OBJECTIVE

To report an unusual case of paraplegia.

SETTING

University Hospital Bursa, Turkey.

CASE REPORT

A 22-year-old woman presented with paraplegia following a left-sided thoracotomy. Magnetic resonance imaging showed a dorsal epidural mass at the level of T6. The patient underwent an emergency T6/7 laminectomy and removal of a tuft of oxidised regenerated cellulose, which had migrated through the intervertebral foramen causing spinal cord compression.

CONCLUSION

In cases of neurological deficits after surgery at the posterolateral edge of a thoracotomy, the clinician should be aware of the above possibility. Urgent radiological diagnosis and decompressive laminectomy is the treatment of choice.

Nitric oxide, lipid peroxidation and antioxidant defence system in patients with active or inactive Behçet's disease

BACKGROUND

One of the prominent features of Behçet's disease (BD) is vasculitis and thrombosis as a result of endothelial dysfunction. Nitric oxide (NO) is responsible for endothelial vasorelaxation and inhibition of platelet adhesion.

OBJECTIVES

To assess serum total NO, erythrocyte superoxide dismutase (SOD), whole blood glutathione peroxidase (GSH-Px), plasma total antioxidant status (TAS) and plasma malondialdehyde (MDA) in patients with BD and to correlate their levels with disease activity.

METHODS

The study group consisted of 49 patients with BD and 26 healthy control subjects. None of the subjects was given a standardized diet. Patients with any systemic disease were excluded. Patients with BD were randomized to two groups according to their disease activity (active/inactive, 26/23). We measured serum total NO levels using the enzyme-linked immunosorbent assay method, and SOD, GSH-Px, TAS and MDA levels by spectrophotometric methods.

RESULTS

In patients with active disease (n = 26), serum total NO levels were found to be significantly decreased when compared with the inactive (n = 23) and control (n = 26) groups. Levels were also significantly lower in patients with inactive disease and in total BD patients (n = 49) than in the controls. GSH-Px activities and TAS levels were significantly lower in total BD patients than those in the controls. Patients with active disease and total BD patients exhibited markedly higher MDA levels than the control subjects. MDA levels in the patients with active disease were also found to be elevated compared with the patients with inactive disease.

CONCLUSIONS

We conclude that changes in parameters associated with oxidative stress such as NO-related processes, activities of antioxidant enzymes in the bloodstream and erythrocytes and total plasma antioxidant capacity are involved in the aetiopathogenesis of the vasculitis seen in BD.

Nickel adsorption on the modified pine tree materials

Removal of nickel ions from aqueous solutions containing 1-100 mg l(-1), using pine tree (Pinus nigra) materials modified with HCl, was investigated on a laboratory scale. For this purpose, two natural adsorbents such as the modified pine bark (MPB) and the modified pine cone (MPC) materials with HCl solution were studied. At first, the required concentration level of the HCl solution for the modification was observed, and then this was followed by the determinations of optimum levels of adsorbent amount, stirring rate, contact time and pH values. Various adsorption isotherms were also obtained by using different concentrations of the heavy metal cations tested in the experiment. As a result, the maximum removal efficiency levels obtained were as follows; 97% for the modified pine bark at pH 8 and 80% for the modified pine cone at pH 8.

Moderate Hypothermia (30 °C) for Surgery of Acute Type A Aortic Dissection

OBJECTIVE

Antegrade cerebral perfusion has proved to be a reliable method of brain protection during surgery of thoracic aneurysms. In addition, the drawbacks of deep hypothermia may be avoided. This study examines the outcome after surgery for acute type A aortic dissections (AAD) using moderate (30 degrees C) systemic hypothermia compared with conventional techniques of cerebral protection.

METHODS

Between January 1999 and August 2003, 74 patients underwent repair of acute type A aortic dissection. Moderate systemic hypothermia (30 degrees C) with selective antegrade cerebral perfusion through subclavian artery (group A) was used in 18 patients. Deep hypothermia (20 - 24 degrees C) was employed using either retrograde (18 patients, group B) or antegrade (38 patients, group C) cerebral perfusion. Tube graft replacement was performed in 55, valve-sparing procedure in 8, and composite graft replacement in 11 patients.

RESULTS

The 30-day mortality was 5.5 % in group A, 5.5 % in group B, and 15.8 % in group C (A vs. C and B vs. C; p < 0.01). New postoperative permanent neurologic deficit occurred in 5.5 % of patients in group A, 16.7 % in group B, and 13.2 % in group C. Mean chest tube drainage within the first 24 h in groups A, B and C was 703 +/- 338, 1178 +/- 820, and 1447 +/- 802 ml, respectively (A vs. B and A vs. C; p < 0.01). Cardiopulmonary bypass, ICU, and hospital times were significantly shorter in group A.

CONCLUSIONS

Selective antegrade cerebral perfusion with moderate systemic hypothermia appears to be a safe and sufficient tool for brain protection during AAD repair. In avoiding deep hypothermia, this technique may help to reduce cardiopulmonary bypass time and hypothermia-related side effects.

Effect of MnSO4 on the chromium removal from the leather industry wastewater

Chromium (VI) is one of the heavy metals in water and wastewater that has the most toxic characteristic. Consequently, it is dangerous for human and environmental health. Various methods are used for removal of the chromium from wastewater, and new methods have been developed in recent years. Recent studies and investigations on the removal of environmental pollution selected methods that were economical, of optimum efficiently and could be carried out easily. In this study, the removal of Cr6+ in the leather industry wastewater is investigated using MnSO4 that was used easily and economically. Experimental studies are performed in two phases. In the first phase, the optimum MnSO4 dose for removal of Cr6+ was determined. In the second phase, the optimum pH was studied. About 96% removal of chromium was launched with 530 mg l(-1) MnSO4 dose at pH value 9 in the wastewater sample.

Segmental myocardial wall motion during minimally invasive coronary artery bypass grafting using open and endoscopic surgical techniques

Current options for minimally invasive surgical treatment of single-vessel coronary artery disease include beating heart procedures without cardiopulmonary bypass (CPB) via mini-thoracotomy (MIDCAB) and totally endoscopic robot-assisted techniques (TECAB) with CPB. Both procedures are associated with potential myocardial stress before revascularization, such as single-lung ventilation (SLV), temporary coronary artery occlusion, cardiac luxation, intrathoracic carbon dioxide insufflation, and extended CPB and operating time. In this echocardiographic study we sought to evaluate the extent of intraoperative segmental wall motion abnormalities (SWMA) during MIDCAB and TECAB surgery and to identify factors affecting SWMA. Forty-six patients with single-vessel coronary artery disease were studied. Sixteen patients were operated using the MIDCAB technique and 30 patients with TECAB. In both groups sequential transesophageal echocardiograms were recorded during the entire procedure. Hemodynamic data and oxygenation variables were acquired simultaneously. In both groups, mild but obvious perioperative SWMA were identified and noted to increase during the course of the operation. These SWMA were more pronounced in the TECAB group. Independent of operating time, these changes disappeared completely after revascularization. No significant hemodynamic compromise was observed. We conclude that MIDCAB and TECAB techniques are associated with significant perioperative SWMA. The appearance of more profound SWMA in the TECAB group compared with the MIDCAB patients might have been the result of intrathoracic CO(2) insufflation, as SLV was used in both groups. No persistent SWMA or post-CPB SWMA were apparent in either group. More extensive intraoperative ventricular SWMA was detected in the TECAB group, suggesting that a more frequent risk for right ventricular dysfunction may exist during TECAB procedures.

Totally endoscopic coronary artery bypass graft: initial experience with an additional instrument arm and an advanced camera system

BACKGROUND

Robotically enhanced telemanipulation for totally endoscopic coronary artery bypass does not provide adequate tactile feedback, traction, or countertraction. The exposition of coronary target sites is difficult, the visual field is limited, and the epicardial stabilization may be troublesome. A fourth robotic arm for endothoracic instrumentation has been added to the da Vinci surgical system to facilitate totally endoscopic operations. The stereoendoscope was upgraded with a wide-angle feature.

METHODS

The procedure was performed in five patients. Four of these patients had left internal thoracic artery (LITA) to left anterior descending artery (LAD) grafting on the beating heart and the fifth had sequential bypass grafting (LITA to diagonal branch and LAD) on an arrested heart. The additional effector arm of the da Vinci surgical system was brought into the operative field beneath the operating table and used as a second right arm. The wide-angle view was activated by either the console or the patient side surgeon.

RESULTS

The mean operative, port placement, and anastomotic times for a beating-heart totally endoscopic coronary artery bypass were 195 +/- 58, 25 +/- 10, and 18 +/- 5 min, respectively. All procedures were free of morbidity and mortality, with satisfactory angiographic control. The sequential arterial bypass grafting procedure was fully completed in totally endoscopic technique.

CONCLUSIONS

The additional instrumentation arm and wide-angle visualization are useful technical improvements of the da Vinci surgical system, solving the problem of traction, countertraction, and facilitated exposition of target sites as well as visualization of the surgical field. They provide potential for wider acceptance of totally endoscopic coronary artery bypass grafting in a larger surgical community.

Multiple Metastatic Malignant Meningioma: A Case Report

We report a case of a 27-year-old man who presented with a clinical history of swelling on the left side of his head. MRI scan showed a left frontal meningioma. The patient underwent a macroscopically complete resection. The histological diagnosis was malignant meningioma. Ten months after the initial diagnosis, multiple distant metastases were detected. Risk factors leading to metastasis in this case are discussed with a review of the literature.

The first records of two cheyletid mites from Turkey: Chelotomimus (Hemicheyletia) wellsi (Baker, 1949) and Hypopicheyla elongata Volgin, 1969 (Acari: Cheyletidae)

Two cheyletid mites, Chelotomimus (Hemicheyletia) wellsi (Baker, 1949) and Hypopicheyla elongata Volgin, 1969, are given as new records for the Turkish fauna, and illustrated. The cheyletid genus Hypopicheyla Volgin, 1969 is reported from Turkey for the first time.

Cardiopulmonary Bypass impairs Left Ventricular Function determined by Conductance Catheter Measurement

OBJECTIVE

Postoperative cardiac depression is attributed to ischemia and the effects of cardiopulmonary bypass (CPB). To evaluate the effect of CPB alone on postoperative left ventricular (LV) dysfunction, we used a conductance catheter to determine the LV performance by pressure-volume relation before and after CPB.

METHODS

Twenty-two 3-week-old piglets underwent sternotomy and normothermic CPB for one hour. A conductance catheter was placed in the LV cavity. End-systolic pressure-volume relationships (ESPVR), left ventricular end-diastolic pressure (LVEDP) and systemic vascular resistance (SVR) were measured under steady-state conditions before and 15 min after weaning from CPB in group A (n = 11). Group B included 11 piglets without CPB and served as control.

RESULTS

There was no difference between groups before initiating CPB. As an indication of depressed LV function, the ESPVR slope (mmHg/ml) was significantly lower in group A after weaning from CPB than in group B (1.69 +/- 0.5 vs. 1.86 +/- 0.55; p = 0.008). In group A, peak dP/dt (max index) (mmHg/s/m (2)) decreased markedly (1596 +/- 339 vs. 2045 +/- 206; p = 0.03), while LVEDP (mmHg) was significantly increased (11.7 +/- 2.6 vs. 5.4 +/- 0.9; p < 0.0001). In addition, SVR (index) (dyn x s x cm (-5)/m (2)) in group A was significantly lower (1407 +/- 176 vs. 1677 +/- 313; p < 0.0001) than in group B.

CONCLUSION

Using the very sensitive conductance catheter technique in a pig model, we could show that CPB leads to a significant depression of LV contractility and elastance even without ischemic arrest.

Effects of low-concentrated chlorhexidine on growth of Streptococcus sobrinus and primary human gingival fibroblasts

The aim of this study was to investigate the in vitro effects of low concentrations of chlorhexidine (CHX) on the proliferation of Streptococcus sobrinus (ATCC 33478) and primary human gingival fibroblasts (HGF). Liquid cultures of bacteria or human gingival fibroblasts were exposed to CHX concentrations ranging from 0.07 to 40 microM in microtiter plates at 37 degrees C for 24 h. Bacteria or cells grown without CHX served as controls. The effects of CHX were determined either by measurements of the optical density (OD) of bacterial cultures or by evaluation of cell growth with the DNA-intercalating fluorescent stain H33342 in comparison to untreated controls. Results were evaluated calculating means and standard deviations. Data were statistically analyzed by an ANOVA using Post Hoc tests ( p<0.005). No growth inhibition of S. sobrinus was found at concentrations between 0.07 and 0.15 microM CHX, whereas 0.3 microM CHX led to an elongated (2 h more) lag phase and 0.6 microM CHX induced a lag phase of 4 h more and a minor inclination of the curve in the log phase. Concentrations of CHX>/=1.25 microM completely inhibited growth of S. sobrinus. On the contrary, CHX showed no significant effect on growth of HGF at concentrations </=5 microM. A slight growth inhibition was only observed at a concentration of 5 microM. CHX-concentrations of 10 and 20 microM reduced cell growth to 88 or 75% of control assays. Data analysis showed that overall treatment effects were highly significant ( p<0.005). Our data reveal that chlorhexidine inhibits proliferation of S. sobrinus even at very low concentrations while concentrations of CHX</=5 microM are not cytotoxic to human gingival fibroblasts.

First report on sequential totally endoscopic thymomectomy and adrenalectomy using computer-enhanced telemanipulation

BACKGROUND

Laparoscopic adrenalectomy is considered the standard method for removal of benign adrenal tumors, regardless of hormone activity. Minimally invasive surgery for thymomectomy aims at limited approaches, avoiding complete sternotomy or large thoracotomy.

METHODS

We report on a case in which totally endoscopic thymomectomy and adrenal gland resection were performed sequentially using a computer-enhanced telemanipulation system within 3 weeks.

RESULTS

Operating time was 4.5 h for totally endoscopic adrenalectomy and 1.5 h for totally endoscopic thymomectomy. The patient was transferred to the normal ward on the day of operation after either procedure and had an uneventful recovery. Pathology yielded no malignancy in both cases.

CONCLUSION

This report demonstrates the safety and feasibility of various totally endoscopic procedures performed sequentially.

Operative techniques in awake coronary artery bypass grafting

BACKGROUND

Off-pump coronary artery bypass grafting was implemented to reduce trauma of surgical coronary revascularization by avoiding extracorporeal circulation. High thoracic epidural anesthesia further reduces intraoperative stress and postoperative pain. In addition, this technique even allows awake coronary artery bypass grafting, avoiding the drawbacks of mechanical ventilation and general anesthesia in high-risk patients.

METHODS

Thirty-four patients underwent awake coronary artery bypass grafting with left internal thoracic artery to left anterior descending coronary artery by partial lower ministernotomy (n = 20), H-graft technique (n = 2), or rib cage-lifting technique (n = 2). In 9 cases we performed double bypass grafting, and in 1 case we performed triple-vessel coronary artery revascularization through complete median sternotomy. In addition to clinical outcomes, visual analog scale pain scores were recorded on days 1, 2, and 3 after surgery.

RESULTS

Thirty-one patients remained awake throughout the whole procedure. Three patients required secondary intubation because of incomplete analgesia (n = 1) or pneumothorax (n = 2). Procedure time was 90 +/- 31 minutes, and recovery room stay was 4.2 +/- 0.6 hours. There were no in-hospital deaths or serious postoperative complications. In 1 case a graft occlusion was documented on predischarge angiography. Early postoperative pain was low (visual analog scale score of 30 +/- 6).

CONCLUSION

These data demonstrate the feasibility and safety of various surgical coronary revascularization techniques without general anesthesia. Continuation of thoracic epidural analgesia provides good pain control and fast mobilization postoperatively. Surprisingly, the awake coronary artery bypass grafting procedure was well accepted by the patients.

[Coronary bypass operation with complete median sternotomy in awake patients with high thoracic peridural anesthesia]

OBJECTIVE

High thoracic epidural anesthesia (TEA) combined with general anesthesia is increasingly being used for coronary artery bypass grafting (CABG) with extracorporeal circulation. Recent developments in beating heart techniques have rendered the use of TEA alone in conscious patients possible and have been reported for single-vessel beating heart CABG via lateral thoracotomy. For multi-vessel revascularization the heart is usually approached via median sternotomy, therefore the use of TEA alone was applied in awake patients with multi-vessel coronary artery disease who underwent CABG via median sternotomy.

METHODS

A total of 10 patients scheduled for awake coronary artery bypass grafting (ACAB) received TEA via an epidural catheter placed at T1/2 or T2/3. Total arterial myocardial revascularization was performed after median sternotomy. In addition to standard monitoring, anesthetic sensory and motor block levels were determined using an epidural scoring scale for arm movements (ESSAM).

RESULTS

Except for one patient who required intraoperative endotracheal intubation due to a pneumothorax, all patients were awake and maintained spontaneous breathing during the entire procedure. Compared to baseline values, hemodynamic parameters, e.g. arterial blood pressure (SAP, MAP, DAP) and heart rate significantly declined during coronary anastomosis. No significant hypercarbia was observed. The intraoperative pain level was subjectively estimated by the patients as less than 20 out of 100 (median 10.95% confidence interval 4.2-21.6) using a visual analogue scale. All patients rated TEA as "good" or "excellent." Adverse effects associated with TEA were not observed.

CONCLUSIONS

We could demonstrate that the use of TEA alone for CABG via median sternotomy was feasible and produced good results. High patient satisfaction in our small and highly selected cohort could be reported. Nevertheless, randomized controlled trials in large cohorts are mandatory to definitively evaluate the role of TEA alone in cardiac surgery.

Computer-enhanced telemanipulation enables a variety of totally endoscopic cardiac procedures

BACKGROUND

Since its introduction in the field of cardiac surgery in 1997, computer-enhanced telemanipulation has been used in a number of different specialized areas. In cardiac surgery, various procedures have been successfully completed in totally endoscopic fashion ever since. Between June 1999 and January 2002, 75 closed-chest cardiac procedures have been performed at our institution using the da Vinci telemanipulation system.

PATIENTS AND METHODS

In 42 patients, a single-vessel totally endoscopic coronary artery bypass was performed on the arrested heart (left internal thoracic artery (LITA) to left anterior descending artery (LAD), n = 36; right internal thoracic artery (RITA) to right coronary artery (RCA), n = 6). 12 patients had different types of multivessel revascularization using both internal thoracic arteries. 8 patients underwent LITA-to-LAD grafting on the beating heart. 10 patients underwent closure of an atrial septal defect (9 direct, 1 patch). 3 patients received an epicardial left ventricular pacemaker lead, 2 of which were reoperations.

RESULTS

Overall conversion rate to any kind of incision was 25 %. The last 26 LITA to LAD patients on the arrested heart had a conversion rate of 4 %. There were no mortalities, 3 patients required reexploration via a median sternotomy, and one patient suffered a hypoxemic brain damage. The first 22 TECAB patients demonstrated excellent graft patency in angiographic control upon discharge. None of the atrial septal defect (ASD) closures showed any residual shunt on the intraoperative transesophageal echocardiogram (TEE). Patients with end-stage heart failure had successful biventricular stimulation.

CONCLUSION

Our current experience confirms the feasibility of various totally endoscopic cardiac procedures with good clinical outcomes. After a steep learning curve, the conversion rate could be lowered to an acceptable figure. Some of these procedures at our institution became a reasonable treatment alternative in selected patients.

Totally endoscopic coronary artery bypass grafting on the arrested heart is a prerequisite for successful totally endoscopic beating heart coronary revascularisation

Telemanipulators have been introduced into cardiac surgery recently expanding the scope of minimally invasive techniques and enabling endoscopic cardiac surgery. Our aim was to evaluate clinical results of totally endoscopic single vessel bypass grafting on the arrested as well as on the beating heart. Since 1999, 44 totally endoscopic single vessel arterial bypass grafting procedures were performed at our institution. Thirty-eight procedures were performed on the arrested heart (group A), and six such procedures on the beating heart (group B) using the daVinci telemanipulation system. In group A, totally endoscopic coronary artery bypass grafting (TECAB) with left internal thoracic artery (LITA) to left anterior descending artery (LAD) was performed in 33 patients and right internal thoracic artery (RITA) to right coronary artery (RCA) grafting in five cases. The overall conversion rate in group A was 18.4% and dropped down to 5% in the last 20 cases. In group B (n=6), four patients received successful LITA to LAD grafting; two patients (33%) required conversion to minithoracotomy. The first 22 TECAB patients of group A (58%) had control angiography and demonstrated excellent graft patency upon discharge. All grafts in group B showed excellent function on angiographic control as well. The mean procedural time for single vessel TECAB was 4.2+/-0.9h, cardiopulmonary bypass (CPB) time was 136+/-32 min and aortic cross-clamp time amounted to 61+/-16 min. The present data show feasibility of totally endoscopic single arterial grafting on the arrested heart in a reproducible manner, though procedural times were still prolonged due to the difficult handling of the port access system and the complex time consuming endoscopic operation. A low conversion rate was achieved in arrested heart TECAB after a relatively short learning curve and is mandatory for successful totally endoscopic off-pump bypass grafting.

Chemical-biological interactions of NaF with three different cell lines and the caries pathogen Streptococcus sobrinus

Fluoride is used in dentistry as a prophylactic agent to reduce caries rates due to the demineralization/remineralization effect and its influence on the metabolism of cariogenic bacteria. The purpose of this study was to evaluate the cytotoxic effects of sodium fluoride (NaF) on three different cell lines and the antibacterial potency on Streptococcus sobrinus. Cell lines were treated with various concentrations of NaF ranging from 0.039 mM to 10 mM for 24 h. For microbial assays, concentrations of NaF between 0.03 mM and 10 mM were added to liquid cultures of bacteria. Our results showed that immortalized human keratinocytes (HaCaT) and human osteogenic sarcoma cells (SAOS-2) were similarly affected by concentrations up to 2.5 mM. However, cell growth of HaCaT was slightly more inhibited at 2.5 mM of NaF than SAOS-2. At concentrations between 0.62 mM and 10 mM, 3T3 mouse fibroblast cells reacted more sensitively than HaCaT and SAOS-2 to NaF. The 3T3 cells did not survive in the presence of 10 mM NaF. NaF caused no significant effect on all tested cells at concentrations of < or = 0.31 mM. NaF at 0.039 mM and 0.06 mM did not affect growth of S. sobrinus. At concentrations of 0.125 mM and 0.5 mM, growth was slightly reduced. The proliferation of S. sobrinus significantly decreased at 1 mM and 2 mM NaF. S. sobrinus survived at 4 mM, revealing a delayed log phase with a decreased proliferation. No viable S. sobrinus cells were detected at concentrations of > or = 8 mM NaF. Data analysis revealed that overall treatment effects were highly significant (P<0.05, analysis of variance, Tukey's difference test). This study indicates that cytotoxic effects due to NaF significantly vary in dependence upon the applied cell line. The toxicity of NaF approached 50% (TC50) at concentrations of 6 mM for HaCaT, 2.3 mM for 3T3 cells, and 7.5 mM for SAOS-2. Additionally, NaF revealed antimicrobial effects only at concentrations that are significantly higher than oral fluoride concentrations.

Totally endoscopic coronary artery bypass grafting on cardiopulmonary bypass with robotically enhanced telemanipulation: report of forty-five cases

BACKGROUND

Robotically enhanced telemanipulation is a new powerful tool for minimally invasive procedures that allows totally endoscopic cardiac surgery. Between June 1999 and February 2001, 45 robotically enhanced totally endoscopic coronary artery bypass grafting procedures on the arrested heart were performed at our institution with the use of the da Vinci telemanipulation system (Intuitive Surgical, Inc, Mountain View, Calif).

METHODS

In 37 patients a single-vessel totally endoscopic coronary bypass operation was performed. Eight patients had different types of multivessel revascularization with both internal thoracic arteries. The initial conversion rate was 22% and dropped to 5% in the last 20 patients. Two patients required reexploration via median sternotomy. The first 22 patients had excellent graft patency on discharge. The procedural time for single-vessel totally endoscopic bypass was 4.2 +/- 0.4 hours, bypass time was 136 +/- 11 minutes, and aortic crossclamp time amounted to 61 +/- 5 minutes.

CONCLUSION

The present data show the feasibility of closed chest single- and double-vessel revascularization, with good clinical results. However, procedural time is prolonged and the complex endoscopic and endoaortic occlusion techniques, as well as the extensive anesthesiologic monitoring, are demanding. The need for conversion to an open procedure diminished after a relatively short learning curve. All postulated benefits of totally endoscopic surgery other than excellent cosmesis must be evaluated in larger cohorts.

[Total arterial bypass operations with complete sternotomy in the awake patient]

BACKGROUND

In minimally invasive coronary artery bypass surgery beating heart procedures and operations via limited incisions became more popular and are routinely performed in many centers. An additional approach to minimize general trauma is avoidance of general anesthesia endotracheal intubation.

PATIENTS AND METHODS

Between March and June 2001, 14 spontaneously breathing patients underwent coronary artery bypass grafting on the beating heart without general anesthesia. Intra- and postoperative analgesia management was performed using continuous epidural infusion of local anesthetics at level Th2-Th3. Single (n = 8) as well as double (n = 5) and triple (n = 1) bypass grafting was performed with the off pump technique. Surgical access to the chest cavity was created via partial (n = 8) or complete sternotomy (n = 6).

RESULTS

Twelve patients remained awake throughout the procedure; 2 patients required secondary intubation due to incomplete sensory block and pneumothorax. Operating time was 94 +/- 18 minutes. Intermediate care monitoring time amounted to 4.8 +/- 0.6 hours. No surgery-related complications or myocardial infarction occurred. Postoperative angiography reviewed good graft function in all patients.

CONCLUSION

Our preliminary experience shows that complete surgical revascularization is safe and feasible without endotracheal intubation and general anesthesia. Thus, invasiveness in cardiac surgery is further reduced with less need for intensive care unit monitoring enabling faster mobilization and recovery.

5 S rRNA and tRNA import into human mitochondria. Comparison of in vitro requirements

In vivo, human mitochondria import 5 S rRNA and do not import tRNAs from the cytoplasm. We demonstrated previously that isolated human mitochondria are able to internalize a yeast tRNA(Lys) in the presence of yeast soluble factors. Here, we describe an assay for specific uptake of 5 S rRNA by isolated human mitochondria and compare its requirements with the artificial tRNA import. The efficiency of 5 S rRNA uptake by isolated mitochondria was comparable with that found in vivo. The import was shown to depend on ATP and the transmembrane electrochemical potential and was directed by soluble proteins. Blocking the pre-protein import channel inhibited internalization of both 5 S rRNA and tRNA, which suggests this apparatus be involved in RNA uptake by the mitochondria. We show that human mitochondria can also selectively internalize several in vitro synthesized versions of yeast tRNA(Lys) as well as a transcript of the human mitochondrial tRNA(Lys). Either yeast or human soluble proteins can direct this import, suggesting that human cells possess all factors needed for such an artificial translocation. On the other hand, the efficiency of import directed by yeast or human protein factors varies significantly, depending on the tRNA version. Similarly to the yeast system, tRNA(Lys) import into human mitochondria depended on aminoacylation and on the precursor of the mitochondrial lysyl-tRNA synthetase. 5 S rRNA import was also dependent upon soluble protein(s), which were distinct from the factors providing tRNA internalization.

Immunohistological and morphometric analysis of inflammatory cells in rapidly progressive periodontitis and adult periodontitis

The purpose of this study was to localize, characterize, and quantify in situ the inflammatory cells in the gingival connective tissue prior and subsequent to the initial therapy of ten patients with rapidly progressive periodontitis (RPP) and five patients with adult periodontitis (AP). Using immunohistological techniques, the amount of T lymphocytes, alphabeta-T lymphocytes, gammadelta-T lymphocytes, B lymphocytes, and plasma cells was determined at the beginning of the periodontal therapy (baseline) and at the time of periodontal surgery. Furthermore, the distribution of collagen types I, III, V, and VI was investigated using transmission electron microscopy. At baseline, patients with RPP revealed much higher numbers of inflammatory cells than patients with AP. During initial therapy of patients with RPP, the amount of T cells, alphabeta-T cells, and gammadelta-T cells was reduced significantly (P<0.05). Biopsies of patients with AP revealed a statistically significant reduction of all cell types, except alphabeta-T cells and gammadelta-T cells in the deep connective tissue. The transmission electron microscopy of biopsies from patients with RPP and AP with severe inflammation taken at baseline revealed that collagen types I and III were destroyed nearly completely in areas with leukocyte infiltration, whereas collagen types V and VI revealed a more pronounced labeling reaction. The results revealed that, during initial therapy, the amount of inflammatory cells was reduced significantly more in biopsies of patients with AP than in patients with RPP. At baseline, the inflamed gingival tissue consists mainly of collagen types V and VI in areas with infiltrates of inflammatory cells.

Effects of various storage media on surface hardness and structure of four polyacid-modified composite resins ("compomers")

It was the purpose of this study to determine surface microhardness and structure of four poly-acid modified composite resins ("compomers") after 1-year storage in water and various solutions. Specimens of the compomers Dyract (DY), Compoglass F (CG), an experimental compomer (EC), and of F2000 (F) were stored at 37 degrees C for 1 year in distilled water, acidic buffer (pH 4.2), neutral buffer (pH 7.0), and neutral buffer supplemented with 1.6 u/ml porcine liver esterase. Then the specimens were kept dry for 3 days further. Continuously dry-stored samples (37 degrees C) served as controls. Surface microhardness (Vickers) was read at baseline (prior to wet storage), after 24 h and 144 h, then every 30 days up to 1 year and after the further 3 days of dry storage. Surface roughness (Ra) was determined at baseline, after 3, 6, 9, and 12 months and, finally, after the further 3 days. In addition, randomly selected control and experimental specimens were investigated by SEM. Data were statistically analyzed by a three-factor ANOVA using Scheffé tests (P<0.05). Vickers hardness of all experimental samples dropped significantly due to wet storage (P<0.000) during the first month. However, the type of storage medium did not influence microhardness significantly. Surface roughness was not altered by wet storage except for compomer F, which revealed pronounced surface cracks in the SEM. Altogether, our findings point out that surface microhardness and structure of the investigated compomers were not significantly deteriorated by the tested intraoral conditions, such as humidity, pH-fluctuation, or the action of hydrolytic salivary enzymes.

Computer-enhanced totally endoscopic sequential arterial coronary artery bypass

Minimally invasive coronary artery bypass grafting of the anterior wall using a left anterior small thoracotomy became a routine procedure within the last 3 years. The introduction of robotics into the cardiosurgical practice in 1998 has finally enabled totally endoscopic closed chest procedures. We report two patients with totally endoscopic left internal thoracic artery bypass grafting to the left anterior descending artery and the first diagonal branch in sequential arterial revascularization technique using the daVinci surgical system.

Robotically enhanced totally endoscopic right internal thoracic coronary artery bypass to the right coronary artery

Computer-enhanced telemanipulation systems allow totally endoscopic coronary artery bypass grafting. This report demonstrates the feasibility of a coronary artery anastomosis between the right internal thoracic artery and the right coronary artery using the daVinci surgical system (Intuitive Surgical, Inc, Mountain View, CA).

Abdominal complications after cardiac surgery

OBJECTIVE

Abdominal complications after cardiac surgery are associated with a high mortality rate. Due to the absence of early specific clinical signs, diagnosis is often delayed. The present study seeks to determine predictive risk factors for subsequent gastrointestinal complications after cardiosurgical procedures.

METHODS

Within 12 months, all patients (n = 1,116) who had undergone open heart surgery with cardiopulmonary bypass at our institution were studied for abdominal complications. To determine predictive factors, all case histories of the patients were analysed.

RESULTS

Abdominal complications occurred in 23 (2.1%) patients during the postoperative intensive care unit (ICU) stay, ten of whom had to undergo subsequent abdominal surgery. Of these 23 patients, 20 died. Early complications occurred most likely on postoperative days 6 and 7, consisting of bowel ischaemia or hepatic failure. Late complications consisted of gastrointestinal bleeding, pseudomembraneous colitis, cholecystitis and septic rupture of a spleen. The relative risk for abdominal complications after cardiopulmonary bypass was highly increased in association with a cardiac index less than 2.0 l/min-1/(m2)-1 (22.1-fold), postoperative onset of atrial fibrillation (16.6-fold), emergency surgery (10.7-fold), need for vasopressors (10.1-fold), need for intra-aortic balloon counterpulsation (8.6-fold), and the need for re-exploration within the first 24 hours (8.4-fold). All patients with necrotic bowel disease had elevated serum lactate levels. Furthermore, both cardiopulmonary bypass and aortic clamping times were significantly prolonged in patients who developed gastrointestinal complications.

CONCLUSIONS

A number of predictive factors has been described to contribute to the development of abdominal complications subsequently after cardiac surgery on cardiopulmonary bypass. Knowledge of these factors may lead to earlier identification of patients at increased risk and may allow for more efficient and earlier interventions.

Two years' clinical experience with a quadrileaflet stentless bioprosthesis in the mitral position

BACKGROUND AND AIMS OF THE STUDY

Currently available bioprosthetic mitral valves do not provide sufficient durability. A new stentless pericardial prosthesis was designed for better hemodynamic performance and reduction of stress load compared with current stented bioprostheses.

METHODS

Between September 1997 and August 1999, the Quadrileaflet mitral valve (QMV) was implanted in 17 patients at our institution. Four patients had minimally invasive mitral valve replacement. Mean patient age was 62.2 +/- 16.3 years; preoperative NYHA class was 3.06 +/- 0.2; ejection fraction was 64.1 +/- 14.7%. Echocardiography was performed pre-, intra- and postoperatively, and at 3-6, 12 and 24 months follow up.

RESULTS

Fifteen patients had an uneventful intra- and postoperative course. Two patients died, one from acute left heart failure at 6 h after surgery, and one on the first postoperative day after resuscitation for ventricular fibrillation. A small-sized prosthesis was implanted in four patients, medium-sized in eight and large-sized in five. The mean duration of cardiopulmonary bypass was 138.3 +/- 37.0 min; mean cross-clamp time was 91.3 +/- 26.3 min. Postoperative control echocardiography showed a mean valve orifice area of 2.5 +/- 0.4 cm2, transvalvular velocity (Vmax) was 1.6 +/- 0.4 m/s, and mean pressure gradient 3.6 +/- 2.0 mmHg. Echocardiographic evaluation after 3, 6 and 12 months showed no significant difference compared with the intraoperative data. Three patients had a minor mitral regurgitation (grade I-II). At 12 months all patients were in NYHA class I or II.

CONCLUSION

The implantation technique of the QMV is more demanding, but the prosthesis is a promising alternative to conventional biological mitral valve replacement. Further follow up is needed to confirm these favorable mid-term results.