Laser-induced interstitial thermotherapy via a single-needle delivery system: Optimal conditions of ablation, pathological and ultrasonic changes.

This study aimed to examine the optimal conditions of laser-induced interstitial thermotherapy (LITT) via a single-needle delivery system, and the ablation-related pathological and ultrasonic changes. Ultrasound (US)-guided LITT (EchoLaser system) was performed at the output power of 2-4 Wattage (W) for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers (n=24), and VX2 tumors implanted in the hind limbs of rabbits (n=24). The ablation area was histologically determined by hematoxylin-eosin (HE) staining. Traditional US and contrast enhanced ultrasound (CEUS) were used to evaluate the treatment outcomes. The results showed: (1) In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 min, and it extended slightly with the ablation time. (2) In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. (3) Gross examination of the liver and carcinoma showed three distinct regions: ablation crater/carbonization, coagulation and congestion distributed from the center outwards. (4) Microscopy revealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and congestion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. (5) The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effectively guide and assess the treatment.

Evaluation of left atrial function in patients with coronary artery disease by two-dimensional strain and strain rate imaging.

BACKGROUND: Left ventricular (LV) dysfunction in patients with coronary artery disease is shown by strain and strain rate imaging. However, left atrium (LA) function in patients with coronary artery disease (CAD) has not been assessed by this method. METHODS AND RESULTS: In 34 CAD patients, including 17 patients with enlarged LA (LA diameter ≤ 4.0 cm) and 17 with normal-size LA (LA diameter ≤ 4.0 cm), two-dimensional strain echocardiographic imaging (2DSE) was performed. Twenty healthy subjects as a control group were included. Both conventional parameters and strain parameters, such as LA peak systolic strain (LAs S/SR), preatrial contraction strain (LAa S), peak systolic (LAs SR), early diastolic strain rate (LAe SR) and late diastolic strain rate (LAa SR), were measured. Conventional parameters were abnormal in CAD patients with enlarged LA (ELA), but there were no significant differences between CAD with normal-size left atrium (NLA) and control groups. LAs S/SR and LAe SR were lower in patients than in normal controls, and were even lower in CAD-ELA group (P < 0.05). LAa S/SR were lower in CAD patients with ELA (P < 0.05), but without a significant difference between CAD-NLA and control groups. A significant correlation was observed between LAs S/SR and LA emptying fraction (r = 0.85, P < 0.05; r = 0.72, P < 0.05, respectively). LAa S/SR related well to LA ejection fraction (r = 0.68, P < 0.05; r = 0.61, P < 0.05, respectively). LAs SR was most accurate in identifying both CAD patients with NLA from controls and CAD patients from controls (area under the curve: 0.91; 0.95, respectively). CONCLUSIONS: LA diastolic dysfunction occurs prior to LA systolic dysfunction in CAD patients, and LAs SR is the most accurate index in identifying patients with CAD.

[Different therapeutic efficacy of pralidoxime chloride PAM-Cl on AChE against acute toxicity of methamidophos, dichlorvos and omethoate].

OBJECTIVE: To observe the treatments on the patients with acute methamidophos dichlorvos (DDV) and omethoate poisoning and provide the reliable basis for the rational treatments on these three organophosphorus pesticides poisoning. METHODS: 101 patients with AOPP in 7 hospitals were divided into three groups: Group A, 59 patients with acute methamidophos poisoning, Group B, 32 patients with acute DDV/dipterex (DEP) poisoning, Group C, 10 patients with acute omethoate/dimethoate poisoning. The levels of erythrocyte AChE and the therapeutic efficacies of pralidoxime chloride (PAM-Cl) were compared among the three groups. RESULTS: The AChE activities of all the three groups were inhibited on level of (9.12 +/- 7.99) U/g Hb (group A), 7.32 +/- 4.62 U/g Hb (group B) and (12.01 +/- 9.53) U/g Hb (group C), among which no significant difference was found (P > 0.05). All the patients recovered from acute cholinergic excitation or crisis after the treatment of PAM-Cl. The erythrocyte AChE activities were obviously reactivated in group A three hours later after admission to hospital, each on level of (11.37 +/- 8.67) U/g Hb, (12.51 +/- 6.98) U/g Hb, (15.90 +/- 7.31) U/g Hb, (18.33 +/- 4.78) U/g Hb and (18.91 +/- 7.00) U/g Hb at the 12th, 24th, 48th, 72nd hour and discharge (P < 0.05), and the upgrade tendency was continuous. AChE activities in group B were also reactivated after treatment, each on level of (8.91 +/- 5.89) U/g Hb, (1.31 +/- 6.61) U/g Hb, (13.00 +/- 7.55) U/g Hb, (14.22 +/- 7.80) U/g Hb, (12.78 +/- 7.07) U/g Hb and (16.87 +/- 7.06) U/g Hb at the 3rd, 12th, 24th, 48th, 72nd hour and discharge, but the upgrade tendency turned slowly after 12 hours, the inhibited AChE activities were not reactivated in group C from the beginning to the end. CONCLUSION: After the treatment of PAM-Cl, the AChE activities of the patients with acute methamidophos poisoning could be continuously reactivated, the AChE activities of the patients with acute DDV/DEP poisoning could also be reactivated in 12 hours, and then keep stable, but the AChE activities of the patients with acute omethoate/dimethoate poisoning could not be reactivated. However, PAM-Cl has therapeutic efficacy against acute toxicity of all the three organophosphorus pesticides. Oximes should be vigorously used in the treatment of AOPP, including acute omethoate/dimethoate poisoning.

[Treatment of mandibular fracture with combined interdental ligation with minimally invasive expansive compression screws].

PURPOSE: To evaluate the therapeutic efficacy of mandibular fracture treatment with combined interdental ligation with minimally invasive expansive compression screws. METHODS: One hundred and sixty-eight patients received this treatment modality. The length of intraoral incision was 3-4 cm. An expansive compression screw was inserted and fixed on the fracture line, and two to three teeth anterior and posterior to the fracture line were ligated. RESULTS: The minimally invasive technique and expansive compression screw supplied continuous pressure with less periosteum stripping. This method led to direct fracture union rather than secondary fracture healing with callus formation. CONCLUSIONS: Combined interdental ligation with minimally invasive expansive compression screw the mandible fracture is easier to carry out than traditional treatment. This technique makes the patient suffer from less pain, with faster fracture healing and no sequela.

Assessment of atrial septal defect area changes during cardiac cycle by live three-dimensional echocardiography.

OBJECTIVES: To investigate the accuracy of measurement of the atrial septal defect (ASD)area and dynamic change by live three-dimensional echocardiography (L3DE). METHODS: L3DE was performed in patients with ASD using a three-dimensional workstation to obtain the en face view of the ASD and measure its area at the peak of P-wave, the peak of R-wave, the initial and the destination point of T-wave, and the period of P-T. Parameters derived from L3DE were compared with intraoperative measurements. RESULTS: The ASD area changed significantly during cardiac cycles (mean change 46.1%, p < 0.0001; range 15.2-72.5%), with the maximal area at endsystole and the minimal area at enddiastole. There was excellent correlation between L3DE and intraoperative measurements for the area of ASD at the peak of P-wave (r = 0.92). There were good correlations between the two methods during the other phases of cardiac cycle (r = 0.81-0.86). CONCLUSIONS: L3DE provides accurate and feasible measurements of the ASD area. Investigation of the dynamic changes during the cardiac cycle may lead to an improved understanding of the hemodynamics of ASD.