Reoperation, myocardial infarction and mortality after transurethral and open prostatectomy: a nation-wide, long-term analysis of 23,123 cases

OBJECTIVE: To analyse long-term rates of reoperation, myocardial infarction and mortality after transurethral (TURP) and open prostatectomy (open PE) in a nation-wide analysis. MATERIAL AND METHODS: Patients who underwent TURP (n=20,671) or open PE (n=2452) in Austria between 1992 and 1996 entered this study and were followed for up to 8 years. Actuarial cumulative incidences of reoperation (TURP, urethrotomy, bladder neck incision), myocardial infarction and death after 1, 5 and 8 years were calculated. Data were provided by the Austrian Health Institute (OBIG). RESULTS: Actuarial cumulative incidences of a secondary TURP after primary TURP at 1, 5 and 8 years were 2.9%, 5.8% and 7.4%; the respective numbers after open PE 1.0%, 2.7% and 3.4%. The overall incidence of a secondary endourological procedure (TURP, urethrotomy, bladder neck incision) within 8 years was 14.7% after TURP and 9.5% after open PE. The 8 years incidence of myocardial infarction was identical after TURP (4.8%) and open PE (4.9%). In parallel, mortality rates at 90 days (TURP: 0.7%; open PE: 0.9%), one year (2.8% vs. 2.7%), 5 years (12.7% vs. 11.8%) and 8 years (20% vs. 20.9%) was identical after TURP and open PE. CONCLUSIONS: This large-scale, contemporary, nation-wide analysis confirms the higher reoperation rate after TURP compared to open PE. We observed no excess risk of myocardial infarction or death after TURP compared to open PE.     

Homeostatic synaptic plasticity can explain post-traumatic epileptogenesis in chronically isolated neocortex

Chronically isolated neocortex develops chronic hyperexcitability and focal epileptogenesis in a period of days to weeks. The mechanisms operating in this model of post-traumatic epileptogenesis are not well understood. We hypothesized that the spontaneous burst discharges recorded in chronically isolated neocortex result from homeostatic plasticity (a mechanism generally assumed to stabilize neuronal activity) induced by low neuronal activity after deafferentation. To test this hypothesis we constructed computer models of neocortex incorporating a biologically based homeostatic plasticity rule that operates to maintain firing rates. After deafferentation, homeostatic upregulation of excitatory synapses on pyramidal cells, either with or without concurrent downregulation of inhibitory synapses or upregulation of intrinsic excitability, initiated slowly repeating burst discharges that closely resembled the epileptiform burst discharges recorded in chronically isolated neocortex. These burst discharges lasted a few hundred ms, propagated at 1-3 cm/s and consisted of large (10-15 mV) intracellular depolarizations topped by a small number of action potentials. Our results support a role for homeostatic synaptic plasticity as a novel mechanism of post-traumatic epileptogenesis.     

Conventional and sutureless techniques for management of the pulmonary veins: Evolution of indications from postrepair pulmonary vein stenosis to primary pulmonary vein anomalies

OBJECTIVE: We have previously reported a limited but favorable experience with a novel sutureless technique for surgical management of postoperative pulmonary vein stenosis occurring after repair of total anomalous pulmonary venous drainage. Because this technique requires integrity of the retrocardiac space for hemostasis, extension of the technique to the primary repair of pulmonary vein anomalies requires evaluation. This analysis reviews our experience with the sutureless technique in patients with postrepair pulmonary vein stenosis, as well as our extension of the technique into primary repair of pulmonary vein anomalies. METHODS: Retrospective univariable-multivariable analysis of all pulmonary vein stenosis procedures and sutureless pulmonary vein procedures over a 20-year period was performed. Cox proportional hazards modeling was used to identify variables associated with freedom from reoperation or death. RESULTS: Sixty patients underwent 73 procedures, with pulmonary vein stenosis present in 65 procedures. The sutureless technique was used in 40 procedures. Freedom from reoperation or death at 5 years after the initial procedure was 49%. Unadjusted freedom from reoperation or death was greater with the sutureless technique for patients with postrepair pulmonary vein stenosis ( P = .04). By using multivariable analysis, a higher pulmonary vein stenosis score was associated with greater risk of reoperation or death. After adjustment, the sutureless repair was associated with a nonsignificant trend toward greater freedom from reoperation or death ( P = .12). Despite the absence of retrocardiac adhesions, operative mortality was not increased with the sutureless technique ( P = .64). Techniques to control bleeding (intrapleural hilar reapproximation) and improve exposure (inferior vena cava division) were identified. CONCLUSION: The sutureless technique for postrepair pulmonary vein stenosis is associated with encouraging midterm results. Extension of the indications for the technique to primary repair appears safe with the development of simple intraoperative maneuvers.     

pT2 classification for renal cell carcinoma. Can its accuracy be improved?

PURPOSE: The 2002 tumor classification for renal cell carcinoma (RCC) classifies pT2 tumors as more than 7 cm in greatest dimension, limited to the kidney. In this study we determined whether a size cutoff point exists within pT2 tumors and whether such subclassification would further improve the accuracy of the current tumor classification. MATERIALS AND METHODS: We studied 544 patients with unilateral, sporadic pT2 RCC treated with radical nephrectomy or nephron sparing surgery between 1970 and 2000. The association of tumor size with death from RCC was examined using martingale residuals from a Cox proportional hazards regression model to determine the optimal size cutoff point. RESULTS: There were 204 deaths from RCC a median of 3.8 years following nephrectomy. Univariately tumor size was significantly associated with death from RCC (risk ratio 1.08, 95% CI 1.04 to 1.13, p <0.001). A scatterplot of tumor size vs expected risk of death per patient suggested that a cutoff point between 9 and 10 cm was appropriate. When adjusted for regional lymph node involvement and distant metastases, the 10 cm cutoff point performed better than the 9 cm point (risk ratio 1.42, 95% CI 1.07 to 1.90, p = 0.017 vs 1.22, 95% 0.86 to 1.72, p = 0.268). Therefore, we propose using a 10 cm cutoff point to subclassify patients into pT2a and pT2b. CONCLUSIONS: Our data suggest that the prognostic accuracy of the 2002 pT2 tumor classification can be further improved by subclassifying patients with tumors greater than 7 and less than 10 cm into a pT2a category, and those with tumors 10 cm or greater into a pT2b category.     

Evaluation of myocardial function in patients with end-stage heart failure during support with the Jarvik 2000 left ventricular assist device.

In 2 patients with the Jarvik 2000 left ventricular assist device (LVAD), we assessed left ventricular systolic function through pressure-volume loops and E(max) at the beginning and end of the support period to potentially predict the possibility of pump removal without transplantation. Immediately before LVAD implantation and explantation, pressure and volume measurements were made with catheters and echocardiography, respectively, the E(max) being calculated from the slope of the pressure-volume loops, and the left ventricular ejection fraction (LVEF) being estimated by echocardiography. Transplantation was performed after 14 and 62 days, respectively, during which the LVEF increased by 75% (from 12% to 21%) in Patient 1 and remained unchanged (from 16% to 18%) in Patient 2, whereas the E(max) increased from 0.63 and 0.42 mm Hg/ml, respectively, to 1.31 and 1.07 mm Hg/ml, reflecting a 107% and 155% improvement. In these 2 cases, the E(max) was a more reliable indicator of intrinsic myocardial contractility than was the LVEF.     

Poor Intraoperative Blood Glucose Control Is Associated with a Worsened Hospital Outcome after Cardiac Surgery in Diabetic Patients

Background: Tight perioperative control of blood glucose improves the outcome of diabetic patients undergoing cardiac surgery. Because stress response and cardiopulmonary bypass can induce profound hyperglycemia, intraoperative glycemic control may become difficult. The authors undertook a prospective cohort study to determine whether poor intraoperative glycemic control is associated with increased intrahospital morbidity.

Methods: Two hundred consecutive diabetic patients undergoing on-pump heart surgery were enrolled. A standard insulin protocol based on subcutaneous intermediary insulin was given the morning of the surgery. Intravenous insulin therapy was initiated intraoperatively from blood glucose concentrations of 180 mg/dl or greater and titrated according to a predefined protocol. Poor intraoperative glycemic control was defined as four consecutive blood glucose concentrations greater than 200 mg/dl without any decrease in despite insulin therapy. Postoperative blood glucose concentrations were maintained below 140 mg/dl by using aggressive insulin therapy. The main endpoints were severe cardiovascular, respiratory, infectious, neurologic, and renal in-hospital morbidity.

Results: Insulin therapy was required intraoperatively in 36% of patients, and poor intraoperative glycemic control was observed in 18% of patients. Poor intraoperative glycemic control was significantly more frequent in patients with severe postoperative morbidity (37% vs. 10%; P < 0.001). The adjusted odds ratio for severe postoperative morbidity among patients with a poor intraoperative glycemic control as compared with patients without was 7.2 (95% confidence interval, 2.7-19.0).     

Independent validation of the 2002 American Joint Committee on cancer primary tumor classification for renal cell carcinoma using a large, single institution cohort

PURPOSE: The primary tumor classification for renal cell carcinoma (RCC) was updated by the American Joint Committee on Cancer in 2002. To date the new classification has not been validated using an independent group of patients and, therefore, its accuracy for predicting patient outcome is unknown. In the current study we evaluated the 2002 primary tumor classification and compared its predictive ability with that of the 1997 classification. MATERIALS AND METHODS: We studied 2,746 patients treated with radical nephrectomy or nephron sparing surgery for unilateral, sporadic RCC between 1970 and 2000. Cancer specific survival was estimated using the Kaplan-Meier method. The predictive abilities of the 1997 and 2002 classifications were compared using the concordance index. RESULTS: There were 812 deaths from RCC a mean of 3.3 years following nephrectomy. Median followup in patients still alive at last followup was 9 years. Estimated 5-year cancer specific survival rates by the 2002 tumor classification were 97%, 87%, 71%, 53%, 44%, 37% and 20% in patients with pT1a, pT1b, pT2, pT3a, pT3b, pT3c and pT4 RCC, respectively. The concordance index for the association between the 2002 classification and death from RCC was 0.752 compared with 0.737 for the 1997 classification, indicating that the 2002 version contained more predictive ability. CONCLUSIONS: Our data suggest that the 2002 primary tumor classification with pT1 cancers subclassified into pT1a and pT1b provides excellent stratification of patients according to cancer specific survival and it has a predictive ability that is superior to that of the 1997 classification.     

Laparoscopic versus standard appendectomy outcomes and cost comparisons in the private sector

Minimally invasive surgery has been proposed as the preferred treatment strategy for various gastrointestinal disorders due to shorter hospital stay, less pain, quicker return to normal activities, and improved cosmesis. However, these advantages may not be straightforward for laparoscopic appendectomy, and optimal management of remains controversial. One hundred forty-eight patients with clinical and radiologic diagnoses of acute appendicitis treated in two different hospitals were retrospectively reviewed. Seventy-eight patients underwent laparoscopic appendectomy in hospital A and 70 patients underwent standard appendectomy in hospital B. Patients treated by either type of surgery were compared in terms of clinical and pathologic features, operation characteristics, complications, and costs. There were no significant differences between both groups in terms of clinical features, radiologic studies, complications, and final pathology findings (P > .05). Hospital stay was significantly shorter and bowel movements recovered quicker in the laparoscopy group. However, overall and operating room costs were significantly higher in patients treated by laparoscopy (P < .01). Our series show a subtle difference in terms of hospital stay and bowel movement recovery, favoring patients treated by laparoscopy. However, these results have to be carefully examined and weighed, because overall costs and operating room costs were significantly higher in the laparoscopy group. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).     

Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf

The East Siberian Arctic Shelf holds large amounts of inundated carbon and methane (CH₄). Holocene warming by overlying seawater, recently fortified by anthropogenic warming, has caused thawing of the underlying subsea permafrost. Despite extensive observations of elevated seawater CH₄ in the past decades, relative contributions from different subsea compartments such as early diagenesis, subsea permafrost, methane hydrates, and underlying thermogenic/ free gas to these methane releases remain elusive. Dissolved methane concentrations observed in the Laptev Sea ranged from 3 to 1,500 nM (median 151 nM; oversaturation by ∼3,800%). Methane stable isotopic composition showed strong vertical and horizontal gradients with source signatures for two seepage areas of δ¹³C-CH₄ = (−42.6 ± 0.5)/(−55.0 ± 0.5) ‰ and δD-CH₄ = (−136.8 ± 8.0)/(−158.1 ± 5.5) ‰, suggesting a thermogenic/natural gas source. Increasingly enriched δ¹³C-CH₄ and δD-CH₄ at distance from the seeps indicated methane oxidation. The Δ¹⁴C-CH₄ signal was strongly depleted (i.e., old) near the seeps (−993 ± 19/−1050 ± 89‰). Hence, all three isotope systems are consistent with methane release from an old, deep, and likely thermogenic pool to the outer Laptev Sea. This knowledge of what subsea sources are contributing to the observed methane release is a prerequisite to predictions on how these emissions will increase over coming decades and centuries.

The East Siberian Arctic Shelf (ESAS) is the world’s largest and shallowest shelf sea system, formed through inundation of northeast Siberia during sea level transgression in the early Holocene. The ESAS holds substantial but poorly constrained amounts of organic carbon and methane (CH₄). These carbon/methane stores are contained in unknown partitions as gas hydrates, unfrozen sediment, subsea permafrost, gas pockets within and below the subsea permafrost, and as underlying thermogenic gas (1–3). Methane release to the atmosphere from these compartments could potentially have significant effects on the global climate (4, 5), yet there are large uncertainties regarding the size and the vulnerability toward remobilization of these inaccessible and elusive subsea carbon/methane pools. Conceptual development and modeling have predicted that warming of the ESAS system by a combination of geothermal heat and climate-driven Holocene heat flux from overlying seawater, recently further enhanced by Anthropocene warming, may lead to thawing of subsea permafrost (6, 7). Subsea permafrost drilling in the Laptev Sea, in part at the same sites as 30 y ago, has recently confirmed that the subsea permafrost has indeed come near the point of thawing (8). In addition to mobilization of the carbon/methane stored within the subsea permafrost, its degradation can also lead to the formation of pathways for gaseous methane from underlying reservoirs, allowing further methane release to the overlying water column (3, 9).Near-annual ship-based expeditions to the ESAS over the past two decades have documented widespread seep locations with extensive methane releases to the water column (3, 10). Methane levels are often found to be 10 to 100 times higher than the atmospheric equilibrium and are particularly elevated in areas of strong ebullition from subsea gas seeps (“methane hotspots”). Similarly, elevated dissolved methane concentrations in bottom waters appear to be spatially related to the thermal state of subsea permafrost as deduced from modeling results and/or geophysical surveys (7, 9). Currently, we lack critical knowledge on the quantitative or even relative contributions of the different subsea pools to the observed methane release, a prerequisite for robust predictions on how these releases will develop. An important distinction needs to be made between pools that release methane gradually, such as methane produced microbially in shallow sediments during early diagenesis or in thawing subsea permafrost, versus pools with preformed methane that may release more abruptly once pathways are available, such as from disintegrating methane hydrates and pools of thermogenic (natural) gas below the subsea permafrost. Multidimensional isotope analysis offers a useful means to disentangle the relative importance of these different subsea sources of methane to the ESAS: Stable isotope data (δ¹³C-CH₄ and δD-CH₄) provide useful information on methane formation and removal pathways, and the radiocarbon content of methane (Δ¹⁴C-CH₄) helps to determine the age and methane source reservoir (see SI Appendix, text S1 for details on these isotope systematics and typical isotopic signatures for the ESAS subsea system).Here, we present triple-isotope–based source apportionment of methane conducted as part of the Swedish–Russian–US investigation of carbon–climate–cryosphere interactions in the East Siberian Arctic Ocean (SWERUS-C3) program. To this end, the distribution of dissolved methane, its stable carbon and hydrogen isotope composition, as well as natural radiocarbon abundance signature, were investigated with a focus on the isotopic fingerprint of methane escaping the seabed to pinpoint the subsea sources of elevated methane in the outer Laptev Sea.     

Quality of life in bridge-to-transplant patients with chronic heart failure after implantation of an axial flow ventricular assist device

Research suggests that ventricular assist devices improve quality of life for congestive heart failure patients awaiting heart transplantation. Axial flow ventricular assist devices like the Jarvik 2000 (Jarvik Heart, Inc., New York, NY) represent the newest type of ventricular assist device technology, but their effects on quality of life are not well understood. Therefore, the authors administered the Minnesota Living with Heart Failure Questionnaire to patients who had the Jarvik 2000 implanted as a bridge to heart transplantation. Patients completed the Minnesota Living with Heart Failure Questionnaire immediately before device implantation, 1 month after implantation, immediately before heart transplantation, and 1 month after transplantation. One month after implantation of the device, the nine patients who completed the study showed significant improvements in physical (p<0.008), emotional (p<0.02), and overall (p<0.008) quality of life. These improvements were maintained until the device was explanted. The authors conclude that implantation of the Jarvik 2000 ventricular assist device can substantially improve quality of life for patients awaiting heart transplantation.