Minimizing Ports During Robotic Partial Nephrectomy

Methods:Data on 11 robot-assisted laparoscopic partial nephrectomies performed by using our technique from February 2015 through June 2015 were retrospectively analyzed. The robotic platform used was DaVinci Xi (Intuitive Surgical, Inc., Sunnyvale, California, USA) with a 3-arm setup. The AirSeal system (SurgiQuest, Milford, Connecticut, USA) was used as a port allowing simultaneous introduction of 2 instruments for the bedside surgeon, obviating the need for an additional (fourth) robotic arm. A long suction-and-irrigation device and atraumatic grasping forceps were used. Both instruments were introduced through the trocar of the AirSeal system, making simultaneous introduction and use possible. We preferred the long suction-and-irrigation device, because it minimizes collision of the instruments.Results:Mean age and BMI of the patients were 55 ±14.6 y and 29.18 ± 6.85, respectively. Seven tumors were on the right side and 4 were on the left. The mean size of the tumors was 32.45 mm (± 11.31). Surgical time was 132.2 minutes (±37.17), with an estimated blood loss and ischemia time of 103.63 mL (±65.92) and 16.72 minutes (±9.52), respectively. One patient had postoperative bleeding that was resolved without transfusion. The median hospitalization period was 3.9 d (±0.53). Loss of intra-abdominal pressure was not observed, and pressure was stable at 10 mm Hg.Conclusion:The AirSeal System and its valveless trocar eliminated the need for an additional port placement in our series. The technique is feasible, safe, and reproducible; therefore, it may be implemented in selected cases of robot-assisted partial nephrectomies.     

Ultra-Violet Light Emission from HPV-G Cells Irradiated with Low Let Radiation From 90Y; Consequences for Radiation Induced Bystander Effects

In this study, we aimed to establish the emission of UV photons when HPV-G cells and associated materials (such as the cell substrate and cell growth media) are exposed to low LET radiation. The potential role of UV photons in the secondary triggering of biological processes led us to hypothesize that the emission and absorption of photons at this wavelength explain some radiation induced “bystander effects” that have previously been thought to be chemically mediated. Cells were plated in Petri-dishes of two different sizes, having different thicknesses of polystyrene (PS) substrate, and were exposed to β-radiation from ⁹⁰Y produced by the McMaster Nuclear Reactor. UV measurements were performed using a single photon counting system employing an interference-type filter for selection of a narrow wavelength range, 340±5 nm, of photons. Exposure of the cell substrates (which were made of polystyrene) determined that UV photons were being emitted as a consequence of β particle irradiation of the Petri-dishes. For a tightly collimated β-particle beam exposure, we observed 167 photons in the detector per unit μCi in the shielded source for a 1.76 mm thick substrate and 158 photons/μCi for a 0.878 mm thick substrate. A unit μCi source activity was equivalent to an exposure to the substrate of 18 β-particles/cm² in this case. The presence of cells and medium in a Petri-dish was found to significantly increase (up to a maximum of 250%) the measured number of photons in a narrow band of wavelengths of 340±5 nm (i.e. UVA) as compared to the signal from an empty control Petri-dish. When coloured growth medium was added to the cells, it reduced the measured count rate, while the addition of transparent medium in equal volume increased the count rate, compared to cells alone. We attribute this to the fact that emission, scattering and absorption of light by cells and media are all variables in the experiment. Under collimated irradiation conditions, it was observed that increasing cell density in medium of fixed volume resulted in a decrease in the observed light output. This followed a roughly exponential decline. We suggest that this may be due to increased scattering at the cell boundary and absorption of the UV in the cells. We conclude that we have measured UVA emitted by cells, cell medium and cell substrates as a consequence of their irradiation by low LET β-particle radiation. We suggest that these secondary UV photons could lead to effects in non-targetted cells. Some effects that had previously been attributed to a chemically mediated “bystander effect” may in fact be due to secondary UV emission. Some radiation bystander effect studies may require re-interpretation as this phenomenon of UV emission is further investigated.     

Fragmented QRS complexes not typical of a bundle branch block: a marker of greater myocardial perfusion tomography abnormalities in coronary artery disease.

BACKGROUND: Fragmented QRS (FQRS) complexes, not typical of a bundle branch block, are a marker of regional myocardial injury. The extent of stress myocardial perfusion imaging (MPI) abnormalities with FQRS patterns is not known. METHODS AND RESULTS: Twelve-lead electrocardiograms (ECGs) in 501 patients undergoing stress MPI were studied. FQRS was defined as a QRS duration of 120 milliseconds or less, with notches or slurs of QRS complexes, on 2 contiguous leads of a coronary artery territory. Abnormal MPI was defined as a regional summed stress score (SSS) and summed rest score (SRS) of 3 or greater based on a 17-segment model. Patients with a typical bundle (n = 26), paced rhythm (n = 2), and Q waves (n = 64) were excluded. Of the remaining 409 patients (mean age, 58 +/- 13 years; 52% male), 155 (38%) had FQRS on the ECG. FQRS patients had a higher mean SSS, SRS, and global summed difference score and a lower left ventricular ejection fraction (all P < .001), as well as greater regional stress MPI scar (69% vs 11%, P < .001). FQRS pattern sensitivity was 75% and specificity was 94% for a corresponding regional MPI scar. On logistic regression, SSS, SRS, summed difference score, left ventricular ejection fraction, and regional scar were univariate predictors of the FQRS pattern on the ECG (all P < .01), and any regional scar (odds ratio, 32; P < .001) was a multivariate predictor. CONCLUSIONS: FQRS complexes on an ECG are a marker of higher stress MPI perfusion and functional abnormalities. Regional FQRS patterns denote the presence of a greater corresponding focal regional myocardial scar on stress MPI.