[Radiation exposure caused by the OrthoScan mini C-arm in hand surgery: a one-year case series]. / Röntgenstrahlenexposition in der Handchirurgie durch den OrthoScan Mini-C-Arm: eine 1-Jahres Fallserie.

BACKGROUND: Mobile X-ray imaging systems are standard in the operating theatre. Mini-C-arms are the prevailing technology in hand surgery. Unfortunately, the exposure to Mini-C-arm radiation is often underestimated. METHODS: For one year, the intraoperative radiation dose delivered by an OrthoScan High Definition Mini-C-arm with a flat panel detector was measured using headband and finger ring dosimeters in all hand and wrist surgeries performed by three experienced hand surgeons. RESULTS: Two hundred and thirteen patients underwent surgical treatment involving the use of an OrthoScan High Definition Mini-C-arm. The total radiation dose administered by all three hand surgeons over 12 months was 9033.39 mGy with a total irradiation time of 376:38 min. A radiation exposure of 2.0 mSv was detected on both finger ring dosimeters of one surgeon during one month. For all other dosimeters, the monthly radiation exposure was below the detection limit of < 0.3 mSv. CONCLUSION: The radiation exposure reached during about 100 surgeries/surgeon/year involving the use of an OrthoScan Mini-C-arm does not exceed the annual occupational exposure limits of 50 mSv for the hand and 20 mSv for the lens of the eye. Only at an X-ray exposure of 800-1000 mGy/month can radiation exposure be detected with a finger ring dosimeter (measuring range 0.3 mSv-10 Sv) in a hand surgeon. Due to the potential health risk posed by stochastic radiation effects, all possible safeguards including behavioural measures should be observed.

Primary early correction of tetralogy of Fallot irrespective of age.

OBJECTIVE: The policy of early repair of patients with tetralogy of Fallot, irrespective of age, as opposed to initial palliation with a shunt, remains controversial. The aim of our study was to analyze the midterm outcome of primary early correction of tetralogy of Fallot. METHODS: Between 1996 and 2005, a total of 61 consecutive patients less than 6 months of age underwent primary correction of tetralogy of Fallot in two institutions. The median age at surgery was 3.3 months, and 27 patients (44%) were younger than 3 months of age, including 12 (20%) newborns. We analyzed the patients in 2 groups: those younger than 3 months of age, and those aged between 3 and 6 months. RESULTS: There was one early (1.6%), and one late death. Actuarial survival was 98.4%, 96.7%, 96.7% at 1, 5, and 10 years respectively, with a median follow up of 4.5 years. There was no difference in survival, bypass time, lengths of ventilation, and hospital stay between the groups. A transjunctional patch was placed significantly more often in the patients younger than 3 months (p = 0.039), with no adverse effect on survival and morbidity during the follow-up. Freedom from reoperation was 98.2%, 92.2%, and 83% at 1, 5, and 10 years respectively, with no difference between the groups. CONCLUSION: Elective primary repair of tetralogy of Fallot in asymptomatic patients is delayed beyond 3 months of age. In symptomatic patients, primary repair of tetralogy of Fallot is performed irrespective of age, weight and preoperative state. This approach is safe, and provides an excellent midterm outcome with acceptable morbidity and rates of reintervention. The long-term benefits of this approach must be established by careful follow-up, with particular emphasis on arrhythmias, right ventricular function, and exercise performance.

Biventricular repair in double outlet right ventricle: surgical results based on the STS-EACTS International Nomenclature classification.

BACKGROUND: The STS-EACTS International Nomenclature for Congenital Heart Surgery (CHS) defines four anatomic subtypes of double outlet right ventricle (DORV) based on the relationship of the ventricular septal defect (VSD) with the great vessels and the presence of right ventricular outflow tract obstruction (RVOTO). We reviewed our experience with DORV patients and two ventricles that underwent repair, applying this nomenclature. METHODS: Between January 2000 and January 2005, 50 patients with DORV and two viable ventricles underwent surgical intervention: 44 patients had biventricular repair, 3 had 1.5 ventricular repair, 2 underwent a Fontan, and 1 died prior to corrective surgery. Median age at repair was 9.1 months (range: 4D-4Y). Eighteen patients (36%) were DORV-Fallot (including 5 with AVSD and heterotaxy), 9 (18%) were DORV-TGA (Taussig-Bing), 12 (24%) were DORV-VSD, and 11 (22%) were DORV non-committed VSD. Corrective surgery included 35 repairs with a VSD-aorta baffle+/-RVOTO procedure and 12 arterial switches with a VSD-PA baffle (9 Taussig-Bing and 3 DORV-ncVSD). Associated procedures included 13 VSD enlargements, 8 subaortic resections, 9 arch repairs, 5 AVSD repairs, and 7 others. RESULTS: There were three deaths in the 50 patients studied (overall mortality of 6%). Excluding one patient that died prior to corrective surgery and the two patients palliated with a Fontan procedure, the actual surgical mortality for a corrective repair was 4.3% (2/47 patients). Two surgical deaths occurred following, respectively, one repair of a Taussig-Bing with an interrupted arch and a Swiss cheese VSD and one repair of ncVSD-type with pulmonary atresia that had undergone a previous cavo-pulmonary anastamosis. No late deaths occurred. Two late reoperations included a heart transplant in a DORV-Fallot patient with Swiss cheese VSD and subaortic resection in a DORV-ncVSD patient. Angioplasties were needed for PA stenosis (n=2) and aortic arch obstruction (n=2). Four patients had LV to aorta baffle gradients between 10 and 20 mmHg. All patients were of NYHA class I/II. CONCLUSIONS: The STS-EACTS International Nomenclature provides more uniform analysis of outcomes with respect to acceptable surgical risk and mortality. Biventricular repair can be safely achieved on selected DORV, including DORV-ncVSD and DORV with AVSD and heterotaxy lesions traditionally indicated for a single ventricle palliative approach.

Ross-Konno procedure in neonates: report of three patients.

The Ross-Konno procedure, applied to neonates with severe left ventricular outflow tract (LVOT) obstruction, offers a satisfactory solution in fully releasing the LVOT gradient, and in replacing the aortic valve with a pulmonary autograft with an excellent growth potential. We reported on three recent neonatal cases.

Improved myocardial function using a Na+/H+ exchanger inhibitor during cardioplegic arrest and cardiopulmonary bypass.

INTRODUCTION: We have demonstrated that a component of post-cardiopulmonary bypass (CPB)/cardioplegic arrest (CPA) myocardial dysfunction is related to myocardial edema. Myocardial ischemia/reperfusion that occurs with CPB/CPA activates the Na(+)/H(+) exchanger to normalize intracellular pH, with intracellular Na(+) (and water) accumulation. We hypothesized that Na(+)/H(+) exchanger inhibition with a selective inhibitor (EMD 87580) would decrease myocardial edema and improve myocardial performance after CPB/CPA. METHODS: Anesthetized dogs (n = 14) were instrumented with myocardial ultrasonic crystals, and left ventricular (LV) micromanometer, to study myocardial function. Myocardial tissue water (MWC) was determined using microgravimetry. Treated animals (n = 5) received EMD 87580 (5 mg/kg IV pretreatment and 10 mol/L cardioplegia); control animals (n = 9) received a saline vehicle. After baseline, hypothermic CPB/CPA was initiated for 2 h, followed by reperfusion/rewarming for 45 min and separation from CPB. Myocardial function parameters and MWC were measured at 30 min, 60 min, and 120 min after CPB. RESULTS: Preload recruitable stroke work did not decrease from baseline in EMD 87580-treated animals, and was significantly greater in EMD 87580-treated animals than control animals at 120 min after CPB. At a similar LV end-diastolic volume, the maximal rate of rise of LV pressure (dp/dtMAX) was significantly decreased from baseline at all time points in control animals, and unchanged in EMD 87580-treated animals. MWC increased with CPB/CPA in both groups, with no difference between groups. There was no difference in - dp/dtMAX or slope of the end-diastolic pressure-volume relationship. CONCLUSION: Na(+)/H(+) exchanger inhibition improves systolic but not diastolic function after CPB/CPA. This is not due to a reduction in MWC.

Myocardial performance after cardiopulmonary bypass and cardioplegic arrest: impact of na+/h+ exchanger inhibition.

This study was designed to determine if pretreatment with a sodium/hydrogen exchange inhibitor (EMD 96 785) improves myocardial performance and reduces myocardial edema after cardioplegic arrest (CPA) and cardiopulmonary bypass (CPB). Anesthetized canines (n = 18) were instrumented with vascular catheters, myocardial ultrasonic crystals, and left ventricle (LV) micromanometer to measure preload recruitable stroke work (PRSW), +dP/dt(max), and cardiac output. Serial myocardial tissue water content (MWC) was determined from sequential biopsy. After baseline measurements, hypothermic (28 degrees C) cardiopulmonary bypass was initiated. CPA was maintained for 2 h, followed by reperfusion/rewarming and separation from CPB. PRSW and myocardial tissue water were measured at 30, 60, and 120 min after CPB. EMD 96 785 (3 mg/kg) was given 15 min prior to CPB. Controls received the same volume of saline vehicle. It was found that MWC increased from baseline in both EMD 96 785 and controls with CPB/CPA. PRSW decreased from baseline at 30 and 60 min post CPB/CPA in controls; PRSW did not decrease from baseline with EMD 96 785, and was statistically greater at 30 and 60 min post CPB/CPA compared to controls. Thus, Na(+)/H(+) exchanger inhibition with EMD 96 785 (3 mg/kg) pretreatment improves post-CPB/CPA myocardial performance without reducing myocardial edema. Na(+)/H(+) exchanger inhibition during cardiac procedures using CPB/CPA may be a useful adjunct to improve immediate post-CPB/CPA myocardial performance.

Sodium/hydrogen-exchanger inhibition during cardioplegic arrest and cardiopulmonary bypass: an experimental study.

OBJECTIVE: We sought to determine whether pretreatment with a sodium/hydrogen-exchange inhibitor (EMD 96 785) improves myocardial performance and reduces myocardial edema after cardioplegic arrest and cardiopulmonary bypass. METHODS: Anesthetized dogs (n = 13) were instrumented with vascular catheters, myocardial ultrasonic crystals, and left ventricular micromanometers to measure preload recruitable stroke work, maximum rate of pressure rise (positive and negative), and left ventricular end-diastolic volume and pressure. Cardiac output was measured by means of thermodilution. Myocardial tissue water content was determined from sequential biopsy. After baseline measurements, hypothermic (28 degrees C) cardiopulmonary bypass was initiated. Cardioplegic arrest (4 degrees C Bretschneider crystalloid cardioplegic solution) was maintained for 2 hours, followed by reperfusion-rewarming and separation from cardiopulmonary bypass. Preload recruitable stroke work and myocardial tissue water content were measured at 30, 60, and 120 minutes after bypass. EMD 96 785 (3 mg/kg) was given 15 minutes before bypass, and 2 micromol was given in the cardioplegic solution. Control animals received the same volume of saline vehicle. Arterial-coronary sinus lactate difference was similar in both animals receiving EMD 96 785 and control animals, suggesting equivalent myocardial ischemia in each group. RESULTS: Myocardial tissue water content increased from baseline in both animals receiving EMD 96 785 and control animals with cardiopulmonary bypass and cardioplegic arrest but was statistically lower in animals receiving EMD 96 785 compared with control animals (range, 1.0%-1.5% lower in animals receiving EMD 96 785). Preload recruitable stroke work decreased from baseline (97 +/- 2 mm Hg) at 30 (59 +/- 6 mm Hg) and 60 (72 +/- 9 mm Hg) minutes after cardiopulmonary bypass and cardioplegic arrest in control animals; preload recruitable stroke work did not decrease from baseline (98 +/- 2 mm Hg) in animals receiving EMD 96 785 and was statistically greater at 30 (88 +/- 5 mm Hg) and 60 (99 +/- 4 mm Hg) minutes after bypass and arrest compared with control animals. CONCLUSIONS: Sodium/hydrogen-exchanger inhibition decreases myocardial edema immediately after cardiopulmonary bypass and cardioplegic arrest and improves preload recruitable stroke work. Sodium/hydrogen-exchange inhibition during cardiac procedures with cardiopulmonary bypass and cardioplegic arrest may be a useful adjunct to improve myocardial performance in the immediate postbypass or arrest period.