5-Year Renal Function Outcomes after SABR for Primary Renal Cell Carcinoma: A Report from the International Radiosurgery Oncology Consortium of the Kidney (IROCK)

PURPOSE/OBJECTIVE(S)

Renal cell carcinoma (RCC) presents uncommonly in patients with a congenital solitary kidney or prior contralateral nephrectomy. The objective of this study was to compare renal function outcomes of stereotactic ablative body radiotherapy (SABR) in patients with solitary vs. bilateral kidneys.

MATERIALS/METHODS

Patients with primary RCC with ≥2 years of follow-up at 12 participating International Radiosurgery Consortium for Kidney (IROCK) institutions were included. Patients with upper tract urothelial carcinoma or metastatic disease were excluded. Renal function was measured by estimated glomerular filtration rate (eGFR). For patients where eGFR was not recorded, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to estimate eGFR based on known creatinine. Baseline characteristics and renal function outcomes were compared between solitary vs. bilateral kidneys. Multivariable logistic regression was used to identify factors predictive of eGFR decline ≥ 15 mL/min and any eGFR increase evaluated at 1-year post-SABR.

RESULTS

One hundred and ninety patients with solitary (n = 56) or bilateral kidneys (n = 134) underwent SABR and were followed for a median of 5.0 years (IQR: 3.4-6.8). Pre-SABR eGFR (mean ± SD) was similar in patients with solitary (61.1 ± 23.2 mL/min) vs. bilateral kidneys (58.0 ± 22.3 mL/min, p = 0.324). Mean tumor size was 3.70 ± 1.40 cm in solitary and 4.35 ± 2.50 cm in bilateral kidneys (p = 0.026). After SABR, an initial compensatory increase in eGFR was observed in both cohorts (22.7% solitary and 17.7% bilateral at 1 year). This compensatory increase persisted in patients with bilateral but not a solitary kidney (10.3% vs. 0% at 3-years and 21.1% vs. 0% at 5-years, respectively). At 5-years post-SABR, eGFR decreased by -14.5 ± 7.6 in solitary and -13.3 ± 15.9 mL/min in bilateral kidneys (p = 0.665). At all timepoints assessed, there were no significant differences in eGFR decline between solitary vs. bilateral cohorts (all p > 0.05). There were also no significant differences in post-SABR end-stage renal disease (7.1% vs. 6.7%) or dialysis (3.6% vs. 3.7%) in solitary vs. bilateral, respectively. Multivariable analysis demonstrated that increasing tumor size (OR per 1 cm: 1.57; 95% CI: 1.14-2.16, p = 0.006) and baseline eGFR (OR per 10 mL/min: 1.30; 95% CI: 1.02-1.66, p = 0.034) was more likely to be associated with eGFR decline ≥ 15 mL/min. There was no significant association between solitary vs. bilateral kidney and eGFR decline (OR: 1.22; 95% CI: 0.45-3.34, p = 0.693).

CONCLUSION

There was no observed difference between renal function outcomes in patients with a solitary vs. bilateral kidneys. While larger tumor size may increase the risk of eGFR decline post-SABR, treatment of a solitary kidney does not appear to increase the risk of renal dysfunction long-term.

Emergence of vancomycin-resistant Enterococcus faecium at a tertiary care hospital in Karachi, Pakistan

Vancomycin-resistant enterococcus (VRE) has not been reported previously in Pakistan. This is the first report where in vancomycin-resistant Enterococcus faecium was isolated from the clinical specimens of six patients admitted to the intensive care unit (ICU) and neonatal intensive care unit (NICU) of the Aga Khan University Hospital, Karachi. To identify the extent of the outbreak, rectal swabs were obtained from all the patients admitted to the ICU and NICU at that time. A total of 10 strains of vancomycin-resistant Enterococcus faecium were isolated. All the strains showed high-level resistance to both glycopeptides (vancomycin and teicoplanin) with a vancomycin minimum inhibitory concentration greater than 256 mg/L. All isolates had the vanA gene detected by polymerase chain reaction. The contour-clamped homogeneous electric field (CHEF) pattern demonstrated that all but one of the isolates were of a single clone, suggesting that they were derived from common source. Use of vancomycin and prolonged hospitalization were common features in all cases investigated.

A comparison of inhaled nitric oxide and milrinone for the treatment of pulmonary hypertension in adult cardiac surgery patients

OBJECTIVE

To investigate the relative effects of milrinone and nitric oxide on pulmonary and systemic hemodynamic responses in cardiac surgery patients with a history of pulmonary hypertension.

DESIGN

Prospective and randomized.

SETTING

University hospital.

PARTICIPANTS

Forty-five adult cardiac surgery patients.

INTERVENTIONS

Cardiac surgery patients with pulmonary hypertension were randomly assigned to one of three study groups: Group 1 patients (n = 15) were treated with intravenous milrinone on separation from cardiopulmonary bypass, group 2 patients (n = 15) with 20 ppm of inhaled nitric oxide, and group 3 patients (n = 15) with 40 ppm of inhaled nitric oxide. Heart rate, right ventricular ejection fraction, and pulmonary vascular resistance were measured throughout the perioperative period at specific data points.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences in demographics, anesthesia, surgery, or baseline hemodynamics among the groups. The group receiving 40 ppm nitric oxide had a significantly higher (p<0.05) right ventricular ejection fraction on arrival in the intensive care unit (40% v. 30% for the milrinone group and 33% for the nitric oxide 20 ppm group). The milrinone group required significantly more phenylephrine in the intensive care unit (p<0.05).

CONCLUSIONS

Treatment of pulmonary hypertension in adult cardiac surgery patients with inhaled nitric oxide compared with milrinone is associated with lower heart rates, higher right ventricular ejection fraction, and a lower requirement for treatment with vasopressor agents.

Assessment of resolution and intercenter reproducibility of results of genotyping Staphylococcus aureus by pulsed-field gel electrophoresis of SmaI macrorestriction fragments: a multicenter study

Twenty well-characterized isolates of methicillin-resistant Staphylococcus aureus were used to study the optimal resolution and interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Five identical isolates (one PFGE type), 5 isolates that produced related PFGE subtypes, and 10 isolates with unique PFGE patterns were analyzed blindly in 12 different laboratories by in-house protocols. In several laboratories a standardized PFGE protocol with a commercial kit was applied successfully as well. Eight of the centers correctly identified the genetic homogeneity of the identical isolates by both the in-house and standard protocols. Four of 12 laboratories failed to produce interpretable data by the standardized protocol, due to technical problems (primarily plug preparation). With the five related isolates, five of eight participants identified the same subtype interrelationships with both in-house and standard protocols. However, two participants identified multiple strain types in this group or classified some of the isolates as unrelated isolates rather than as subtypes. The remaining laboratory failed to distinguish differences between some of the related isolates by utilizing both the in-house and standardized protocols. There were large differences in the relative genome lengths of the isolates as calculated on the basis of the gel pictures. By visual inspection, the numbers of restriction fragments and overall banding pattern similarity in the three groups of isolates showed interlaboratory concordance, but centralized computer analysis of data from four laboratories yielded percent similarity values of only 85% for the group of identical isolates. The differences between the data sets obtained with in-house and standardized protocols could be the experimental parameters which differed with respect to the brand of equipment used, imaging software, running time (20 to 48 h), and pulsing conditions. In conclusion, it appears that the standardization of PFGE depends on controlling a variety of experimental intricacies, as is the case with other bacterial typing procedures.

Polymerase chain reaction-mediated typing of microorganisms: tracking dissemination of genes and genomes

The polymerase chain reaction (PCR) is a powerful molecular biology tool which can be used for the identification of species and strains of diverse microorganisms. By aimed amplification of characteristic genes (i.e., genes encoding ribosomal RNA molecules) and subsequent genetic analysis of amplified fragments, information on microbiological systematics and phylogeny can be obtained in a fast and efficient manner. Similar types of gene identification can be used to verify or detect genes responsible for phenotypic characteristics, whereas modified forms of the PCR enable whole genome searches for genetic polymorphisms among strains of a given species. In medical sciences, both strategies, gene and genome variability analysis by PCR, have an increasing impact on the study of the spread of especially those microbes that are multiply resistant to clinically used antibiotics. In this communication we will exemplify the usefulness of PCR-mediated typing of microorganisms from a clinical perspective while focusing on gene- versus genome-scanning. Special emphasis will be placed on analysis of the dissemination and characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains and bacterial factors providing resistance to penicillin and other beta-lactam antibiotics. Technical limitations and possibilities for improvement will be discussed.

Antibiotic resistance and genomic analysis of enterococci in an intensive care unit and general wards

Fifty-nine enterococci isolated from 18 patients in an intensive care unit (ICU) and 21 patients in general wards (GW) at Royal Perth Hospital (RPH) during a period of 14 months were examined for antibiotic resistance by susceptibility testing and DNA polymorphism by pulsed-field gel electrophoresis. The study showed that penicillin-resistant Enterococcus faecium is a common nosocomial isolate in ICU. The DNA patterns of various strains of E. faecium and E. faecalis were closely related in most consecutive isolates from the same patients but were generally different for isolates from different patients. Thirty two different DNA patterns were identified for 59 isolates from 39 patients. Identical or similar DNA patterns were also identified for some isolates from different patients, suggesting that cross-infection had occurred between patients in ICU and GW. These data suggest that cross-infection occurred more commonly in ICU than in GW and are consistent with the known higher risk of ICU patients for nosocomial infection.

Bystander vs EMS first-responder CPR: initial rhythm and outcome in witnessed nonmonitored out-of-hospital cardiac arrest

OBJECTIVES

To assess whether outcome and first-monitored rhythm for patients who sustain a witnessed, nonmonitored, out-of-hospital cardiac arrest are associated with on-scene CPR provider group.

METHODS

A retrospective, cohort analysis was conducted in a suburban, heterogeneous EMS system. Patients studied were > or = 19 years of age, had had an arrest of presumed cardiac origin between July 1989 and January 1993, had gone into cardiac arrest prior to ALS arrival, and had received CPR on collapse. First-monitored rhythms and survival rates were compared for two patient groups who on collapse either: 1) had received CPR by nonprofessional bystanders (BCPR) or 2) had received CPR by on-scene EMS system first responders (FRCPR).

RESULTS

Of 217 cardiac arrest victims, 153 (71%) had received BCPR and 64 (29%) had received FRCPR. The BCPR patients were slightly younger (62.4 vs 68.4 years, p = 0.01) and had slightly shorter ALS response intervals (6.4 vs 7.7 minutes, p = 0.02). There was no difference in BLS response time intervals or automatic external defibrillator (AED) use rates. The percentage of patients with a first-monitored rhythm of pulseless ventricular tachycardia/ventricular fibrillation (VT/VF) and the percentage of patients grouped by CPR provider who survived to hospital admission or to hospital discharge were: [see text]

Bystander CPR, ventricular fibrillation, and survival in witnessed, unmonitored out-of-hospital cardiac arrest

STUDY OBJECTIVE

To assess whether bystander CPR (BCPR) on collapse affects initial rhythm and outcome in patients with witnessed, unmonitored out-of-hospital cardiac arrest (OHCA).

DESIGN

Prospective cohort study. Student's t test, the chi 2 test, and logistic regression were used for analysis.

SETTING

Suburban emergency medical service (EMS) system.

PARTICIPANTS

Patients 19 years or older with witnessed OHCA of presumed cardiac origin who experienced cardiac arrest before EMS arrival between July 1989 and July 1993.

RESULTS

Of 722 patients who met the entry criteria, 153 received BCPR. Patients who received BCPR were younger than those who did not: 62.5 +/- 15.4 years versus 66.8 +/- 15.1 years (P < .01). We found no differences in basic or advanced life support response intervals or in frequency of AED use. More patients initially had ventricular fibrillation (VF) in the BCPR group: 80.9% versus 61.4% (P < .01). The interval to definitive care for ventricular tachycardia (VT)/VF was longer for the BCPR group (8.59 +/- 5.3 versus 7.45 +/- 4.7 minutes; P < .05). The percentage of patients discharged alive who were initially in VT/VF was higher in the BCPR group: 18.3% versus 8.4% (P < .001). In a multivariate model, BCPR is a significant predictor for VT/VF and live discharge with adjusted ORs of 2.7 (95% CI, 1.7 to 4.4) and 2.4 (95% CI, 1.5 to 4.0), respectively. For those patients in VT/VF, BCPR predicted live discharge from hospital with an adjusted OR of 2.1 (95% CI, 1.2 to 3.6).

CONCLUSION

Patients who receive BCPR are more often found in VT/VF and have an increased rate of live discharge, with controls for age and response and definitive care intervals. For VT/VF patients, BCPR is associated with an increased rate of live discharge.

Chronic renal vein thrombosis

Twenty-eight patients with demonstrated chronic renal vein thrombosis were studied. In seven, only small venous channels were involved; in 21, both small and large veins were thrombosed. A constellation of findings occurred with such frequency in these patients that we believe it virtually diagnostic of renal venous obstruction. These findings include the nephrotic syndrome, great variability in proteinuria and glomerular filtration rate, pulmonary embolization, sterile pyuria, hematuria, hyperchloremic acidosis, decreased renal tubular threshold for glucose and increased fibrin degradation products. These findings are an indication for definitive angiographic and biopsy procedures. Prolonged anticoagulant therapy was generally very effective.

Reversible systemic abnormalities associated with renal cell carcinoma

A sixty-eight-year-old male was found to have renal carcinoma after seven months of constitutional symptoms. Initial study of the patient showed a puzzling array of laboratory abnormalities. These led initially to a search for gastrointestinal malignancy and then later to consideration of multiple myeloma. This case serves as a reminder of the propensity of early renal carcinoma to produce striking constitutional symptoms and marked hematologic and serum protein abnormalities. These may occur in the absence of metastases and are frequently reversible as shown in this case with resection of the primary lesion.