Impacts of percutaneous nephrolithotomy on the estimated glomerular filtration rate during the first few days after surgery

Long-term effects of percutaneous nephrolithotomy (PCNL) on renal function have been evaluated in many studies but there are little data on the renal effects of PCNL immediately after surgery in human patients. The aim of this study was to evaluate estimated glomerular filtration rate (GFR) during the first few days after PCNL. From July to September 2008, we gathered preoperative and postoperative serum creatinine data of all the patients who underwent PCNL at our center. Children and patients who received transfusion during surgery were excluded. Creatinine clearance was estimated by Cockcroft–Gault equation and was used to estimate GFR. 94 patients met the inclusion criteria. The mean ± SD of creatinine clearance by Cockcroft–Gault equation was 87.5 ± 32.2 cc/min before operation. It decreased to 85.5 ± 29.4 cc/min, 77.0 ± 26.8 cc/min and 75.9 ± 25.0 cc/min at 6, 24 and 48 h after operation and then increased slightly to 81.9 ± 26.4 cc/min 72 h after operation. Renal GFR decreases immediately after PCNL reaches a nadir 48 h after operation, and then, increases slowly. It seems advisable to avoid factors that can bear a negative influence on renal function during the early postoperative period such as nephrotoxic drugs, contrast agents, shock wave lithotripsy and Re-PCNL.     

Longitudinal analysis of performance of estimated glomerular filtration rate as renal function declines in chronic kidney disease

Background. Numerous studies have assessed the accuracy of equationsestimating glomerular filtration rate (eGFR) from serum creatininein individuals with chronic kidney disease (CKD) in cross-sectionalstudies. Limited literature exists, however, on the consistencyof performance of these equations in longitudinal studies asrenal function declines. Methods. Radionucleotide-measured GFR from 155 predialysis patientswith stage 3–5 CKD was compared with eGFR derived fromfour equations [6-variable Modification of Diet in Renal Disease(6-MDRD), 4-variable MDRD (4-MDRD), Cockcroft–Gault (CG)and Cockcroft–Gault equations corrected for body surfacearea (CGC)] at baseline, 12 and 24 months. Bias (differencebetween eGFR and measured GFR) was used as a measure of performance.Restricted Maximum Likelihood (REML) models were used to identifyvariables potentially affecting the performance of estimatingequations across time. Results. Mean measured GFR (±SD) at baseline, 12 and24 months was 25.9 ± 10.7, 23.1 ± 10.6 and 20.3± 10.1 mL/min/1.73 m², respectively. There was a statisticallysignificant negative association between bias and GFR for allfour estimates (range: –0.76 to –0.71, P < 0.001for all), indicating worsening underestimation and overestimationat higher and lower GFR, respectively. This negative associationsignificantly reduced over the 24 months (P < 0.001); however,this was largely due to persistent underestimation of eGFR fromindividuals with GFR >50 mL/min/1.73 m². For those with abaseline GFR <50 mL/min/1.73 m², the change in bias for anyof the four equations over 24 months was 1.1 mL/min/1.73 m²,suggesting relatively preserved performance with time. The MDRDequations showed a sustained advantage in estimating renal functionthat was more evident as GFR declined. Conclusion. GFR estimates are inexpensive and show an acceptablelongitudinal performance for monitoring CKD patients with GFR<50 mL/min/1.73 m². Inaccuracies appear more substantialabove this level of GFR, and care with interpretation is required.     

Circadian rhythms of diuresis,proteinuria and natriuresis in children with chronic glomerular disease

The aim of our study was to examine diurnal variation in urine volume (UV) output, proteinuria (UPRT), urine creatinine (UCr) and urine sodium ion excretion (UNa) in children with chronic glomerulopathy. In 56 patients (20 boys/36 girls, aged 11.7 ± 0.6 years) samples for UPRT, UCr and UNa were collected during the day and night, with continuous ambulatory blood pressure (BP) monitoring. On the basis of creatinine clearance (CrCl) the patients were divided into group I (n = 44, with CrCl 131 ± 3.6 ml/min per 1.73 m² body surface area), or group II (n = 12, with CrCl 44.6 ± 7.7 ml/min per 1.73 m² body surface area). Nocturnal polyuria was defined as night time UV ≥ 35% of the 24 h UV. Age, gender, body mass index of the patients, 24 h UV, UCr and UNa were similar in both groups. However, arterial hypertension and nocturnal polyuria were widespread (P < 0.01) in group II. In addition, proteinuria was higher (P < 0. 05) in group II. The nocturnal decline in CrCl, UV, UPRT and UNa was significantly attenuated (P < 0.005) in patients in group II compared with those in group I. The night time mean arterial pressure (MAP), as well as the night/day ratios of MAP, UV, UPRT and UNa, showed negative associations with CrCl. Our findings strongly suggest that renal function diurnal variation and nocturnal MAP are related to decreased glomerular filtration rate at the time of examination.     

GFR prediction using the MDRD and Cockcroft and Gault equations in patients with end-stage renal disease.

BACKGROUND: Although prediction equations are recommended to determine GFR and creatinine clearance (CrCl), neither the MDRD equations nor the Cockcroft and Gault formula have been validated for the low levels of GFR present in end-stage renal disease (ESRD). The accuracy of the MDRD equations and the Cockcroft and Gault formula in predicting GFR and CrCl, respectively, was examined in patients with ESRD and its relationship to the basal GFR and two markers of malnutrition, urinary creatinine and body fat determined. METHODS: Inulin clearance (C(in)) was measured in 26 non-diabetic patients with ESRD and the 24 h CrCl determined. GFR was predicted using three equations derived from the MDRD study population containing four to six variables. Both CrCl and GFR were predicted from the Cockcroft and Gault formula. Estimates of bias and precision were obtained and Bland and Altman analysis performed. Body fat was measured by DEXA scan. RESULTS: The predicted GFR (MDRD) was 10% lower than C(in) (8.83+/-0.71 ml/min/1.73 m2) with all three MDRD equations, showing a similar degree of precision and bias. C(in) gave a negative correlation with the difference between the predicted GFR (MDRD) and the measured GFR. The predicted GFR (MDRD) underestimated GFR when C(in) >8 ml/min/1.73 m2 but overestimated GFR when C(in) <8 ml/min/1.73 m2. The Cockcroft and Gault formula overestimated CrCl by 14% and overestimated C(in) by 35%. C(in) gave a negative correlation with the difference between the predicted GFR (Cockcroft and Gault) and measured GFR, overestimating GFR when C(in) <13 ml/min/1.73 m2. The overestimation of GFR by the MDRD equation was not associated with urinary creatinine excretion. However, both Cockcroft and Gault and the MDRD predictions showed a positive, but weak, correlation with body fat. CONCLUSION: The MDRD equations were more accurate in predicting the group mean GFR in patients with ESRD than the Cockcroft and Gault formula. However, the predicted GFR using either formula was related to the basal GFR and percentage body fat.     

The effects of combined epidural and general anesthesia on the autonomic nervous system and bioavailability of nitric oxide in patients undergoing laparoscopic pelvic surgery

Background

Pneumoperitoneum during laparoscopic surgery is known to affect visceral blood flow and result in oxidative stress. Whether epidural anesthesia will effectively reduce visceral ischemia and oxidative stress by blocking the sympathetic nervous system (SNS) during laparoscopic surgery has not been proven.

Methods

Forty-five patients who were to undergo robot-assisted laparoscopic prostatectomy were randomly assigned to the combined general–epidural anesthesia group (group GE, n = 22) or to the general anesthesia group (group G, n = 23). Blood pressure, heart rate, and the balance between sympathetic and parasympathetic nervous system activity as measured by heart rate variability were recorded at 10 min after induction of anesthesia (T1), 60 (T2) and 120 (T3) min after intra-abdominal CO₂ insufflation, and 10 min after returning the patient to the supine position following CO₂ exsufflation (T4). Arterial blood gas analysis and blood sampling for measurements of nitrite (NO^2?) and malondialdehyde (MDA) were performed at all time points.

Results

Intraoperative mean blood pressure was significantly lower in group GE compared with group G. The low-frequency to high-frequency ratio was significantly increased after induction of pneumoperitoneum in group G but was unchanged in group GE. Plasma levels of nitrite decreased after pneumoperitoneum induction in group G while there was no change in group GE. A significant increase in MDA levels was seen in group G after pneumoperitoneum induction and were higher than group GE at T3 and T4. The 24-h urine output was higher in group GE than in group G on POD 1. The 24-h CrCl was higher in group GE on POD 1 but was not different between groups on POD 2.

Conclusions

Combined epidural and general anesthesia effectively blocks SNS stimulation during laparoscopic surgery and reduces NO inactivation and oxidative stress.     

Immunologic parameters during NOTES compared with laparoscopy in a randomized blinded porcine trial

Background  It remains unclear if the natural orifice translumenal endoscopic surgery (NOTES) technique is less invasive than laparoscopy. Serum interleukins and peritoneal cellular response have been utilized to support the immunologic difference between open and laparoscopic surgery. We hypothesized that there would be no difference between cytokine levels during NOTES or laparoscopic peritoneoscopy. Methods  Twelve pigs were assigned to NOTES or standard laparoscopy with permuted block randomization. Each group underwent 90 min of diagnostic peritoneoscopy using CO₂ for laparoscopy and air for NOTES pneumoperitoneum. Blood draws were obtained at baseline, at procedure end, and on postoperative days (POD) 1, 2, and 7. Quantification of cytokines (IL-1b and TNF-α) was performed with a Duo Set Porcine enzyme-linked immunosorbent assay (ELISA). Laboratory results were captured by a technician blinded to the research question, and data analysis was performed by an investigator blinded to the procedure using t-test and repeated measures linear model. The study was approved by the institutional animal care and use committee (IACUC). Results  All procedures were successfully completed. One NOTES animal succumbed to hemorrhagic gastritis (day 3). All other animals thrived to POD 14, with no gross infections at necropsy. Animals undergoing laparoscopy had lower mean arterial pH than NOTES animals (p < 0.001). Serum and intraperitoneal white blood cell (WBC) counts were similar between the groups. Mean interleukin-1b levels at baseline, at the end of the procedure and at 48 h did not differ (0.50 and 0.31; p = 0.65). TNF-α levels did not differ at baseline or procedure end but increased in the NOTES group on POD 1, persisting to POD 7. Tumor necrosis factor-α (TNF-α) decreased in the laparoscopy group (p = 0.005). Conclusion  Cytokines and WBC did not differ between laparoscopic and NOTES groups during the initial 24 h. These findings do not currently support the assumption that NOTES is less invasive than laparoscopy. The late TNF-α elevation contradicts other studies and requires further examination. Presented at the 27th annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), April 9–12th, Philadelphia, PA.     

Prevalence of chronic kidney disease in Kinshasa: results of a pilot study from the Democratic Republic of Congo

Background. The burden of chronic kidney disease (CKD) in sub-SaharanAfrica is unknown. The aim of this study was to investigatethe prevalence and the risk factors associated with CKD in Kinshasa,the capital of the Democratic Republic of Congo (DRC). Methods. In a cross-sectional study, 503 adult residents in10 of the 35 health zones of Kinshasa were studied in a randomlyselected sample. Glomerular filtration rate was estimated usingthe simplified Modification of Diet in Renal Disease Study equation(eGFR) and compared with the Cockcroft–Gault equationfor creatinine clearance. The associations between health characteristics,indicators of kidney damage (proteinuria) and kidney function(<60 ml/min/1.73 m²) were examined. Results. The prevalence of all stages of CKD according to K/DOQIguidelines was 12.4% [95% confidence interval (CI), 11.0–15.1%].By stage, 2% had stage 1 (proteinuria with normal eGFR), 2.4%had stage 2 (proteinuria with an eGFR of 60–89 ml/min/1.73m²), 7.8% had stage 3 (eGFR, 30–59 ml/min/1.73 m²) and0.2% had stage 5 (eGFR < 15 ml/min/1.73 m²). Hypertensionand age were independently associated with CKD stage 3. Theprevalences of major non-communicable diseases considered inthis study were 27.6% (95% CI, 25.7–31.3%) for hypertension,11.7% (95% CI, 10.3–14.4%) for diabetes mellitus and 14.9%(95% CI, 13.3–17.9%) for obesity. Hypertension was alsoindependently associated with proteinuria. Conclusion. More than 10% of the Kinshasa population exhibitssigns of CKD, which is affecting adults in their productiveyears. Risk factors for CKD, including hypertension, diabetesand obesity, are increasing. These alarming data must guidecurrent and future healthcare policies to meet the challengeraised by CKD in this city and hopefully in the whole country.     

Robotic partial nephrectomy outcomes at a single institution and experience with R.E.N.A.L. nephrometry score

Partial nephrectomy is the current gold-standard treatment of small renal masses. The articulated instruments of the surgical robot have made the laparoscopic approach more feasible. We present our experience with 50 robot-assisted laparoscopic partial nephrectomy (RALPN) surgeries and attempt to validate a recently reported nephrometry score. From July 2008 to July 2010, 50 (53 planned) elective RALPNs were performed utilizing the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA). All patients had an enhancing renal mass on CT scan pre-operatively. Clinicopathologic, surgical, and renal functional (Cockcroft–Gault formula) outcomes were recorded prospectively and analyzed. Mean tumor size, length of surgery (LS), warm ischemia time (WIT), and nephrometry scores were 3.6 cm (1–8), 303 min (133–610), 29.1 min (11–42), and 6.8 (4–11) respectively. Renal cell carcinoma was found in 39 (78%) patients. When evaluating the nephrometry score, comparison of low, medium, and high complexity tumors for length of surgery, WIT, and estimated blood loss (EBL) showed no difference (p > 0.05). Nearness to the collecting system (N score 1 vs. N score 3) showed increased EBL (195 ml vs. 510 mL, p = 0.005), and location relative to polar lines (L score 1 and L score 2) increased mean LS (265 vs. 359 min, p = 0.02). RALPN is safe and effective. Nephrometry scores are a method of standardizing tumor complexity and can be utilized in comparing tumor cohorts but may not be predictive of intra-operative outcomes.     

Sobh Formula: A New Formula for Estimation of Creatinine Clearance in Healthy Subjects and Patients with Chronic Renal disease

Backgrounds: Cockcroft–Gault formula overestimates creatinine clearance (Ccr) in obese or edematous patients. This limitation urged us to develop a new formula that can overcome the limitation of Cockcroft–Gault formula. Methods: We developed a new formula suitable for rapid bedside estimation of creatinine clearance in healthy adults and elderly persons and patients with chronic renal disease considering the surface area as a reliable factor for estimation of creatinine clearance. This cross sectional study included 182 individuals (healthy persons and patients with chronic kidney disease). Ccr was estimated by different methods including 24 hours urine collection, Cockcroft–Gault equation, and our new formula, and ^99mTc-DTPA isotope clearance which was considered as a standard method for comparison between the other methods.Results: Our new formula had a statistically significant higher correlation coefficient with the standard ^99mTc-DTPA isotope clearance for all groups included in this study (r=0.97) than either Cockcroft–Gault formula (r=0.90) or 24 hours urine collection method (r=0.88). Conclusion: Our formula is a step forward for a better bedside assessment of kidney function in both healthy individuals and patients with chronic kidney disease.     

Hemodynamic profile during laparoscopic cholecystectomy versus laparoscopic bariatric surgery: the impact of morbid obesity

The present study investigated the hemodynamic profile using impedance cardiography (ICG) monitor during pneumoperitoneum for laparoscopic cholecystectomy versus bariatric surgery in order to determine the impact of body weight on hemodynamics. METHODS. 32 adult patients (two groups, each 16 patients) were studied. Group 1 (16 patients) scheduled to undergo laparoscopic cholecystectomy (lapchole) with body mass index (BMI) 28 +/- 5 kg/m2. Group 2 (16 patients) scheduled to undergo laparoscopic adjustable band (LAGB) surgery for treatment of morbid obesity with BMI 45.3 +/- 8 kg/m2. under general anesthesia. Besides routine monitoring, impedance cardiography was used for hemodynamic monitoring. Three stages were identified for statistical analysis A, pre-insufflation, B, during vere pneumoperitoneum and C, at gas deflation. RESULTS. The mean values of cardiac index in group 1 at stages A, B and C were, 3.0 +/- 1.7, 2.5 +/- 0.5 and 2.7 +/- 0.5 L/min/m2 respectively with significant low values in stage B compared to stage A (p < 0.05). The same trend continue in group 2 where the mean values were, 2.4 +/- 0.6, 1.8 +/- 0.6 and 2.3 +/- 0.9 L/min/m2 respectively with significant differences compared to group 1 mean values (p < 0.05). Other hemodynamic variables showed non-significant differences (p > 0.05). CONCLUSIONS. Cardiac index showed significant decreasing trend in morbid obese patients compared to nonobese, which may reflect the effect of body weight on hemodynamics. On the other hand other hemodynamic parameters was not altered by body weight. We believe that hemodynamics should be closely monitored during laparoscopic surgery with pneumoperitoneum.     

Hemodynamic profile during laparoscopic cholecystectomy versus laparoscopic bariatric surgery--the impact of morbid obesity

The present study investigated the hemodynamic profile using impedance cardiography (ICG) monitor during pneumoperitoneum for laparoscopic cholecystectomy versus bariatric surgery in order to determine the impact of body weight on hemodynamics. METHODS: 32 adult patients (two groups, each 16 patients) were studied. Group 1 (16 patients) scheduled to undergo laparoscopic cholecystectomy (lapchole) with body mass index (BMI) 28 +/- 5kg/m2. Group 2 (16 patients) scheduled to undergo laparoscopic adjustable band (LAGB) surgery for treatment of morbid obesity with BMI 45.3 +/- 8kg/m2. under general anesthesia. Besides routine monitoring, impedance cardiography was used for hemodynamic monitoring. Three stages were identified for statistical analysis A, pre-insufflation, B, during pneumoperitoneum and C, at gas deflation. RESULTS: The mean values of cardiac index in Group 1 at stages A, B and C were, 3.0 +/- 1.7, 2.5 +/- 0.5 and 2.7 +/- 0.5L/min/m2 respectively with significant low values in stage B compared to stage A (P<0.05). The same trend continue in Group 2 where the mean values were, 2.4 +/- 0.6, 1.8 +/- 0.6 and 2.3 +/- 0.9L/min/m2 respectively with significant differences compared to Group 1 mean values (P<0.05). Other hemodynamic variables showed non-significant differences (P>0.05). CONCLUSIONS: Cardiac index showed significant decreasing trend in morbid obese patients compared to nonobese, which may reflect the effect of body weight on hemodynamics. On the other hand, other hemodynamic parameters was not altered by body weight. We believe that hemodynamics should be closely monitored during laparoscopic surgery with pneumoperitoneum.     

Prospective assessment of the safety and benefit of laparoscopic liver resections

Abstract. Background/Purpose: Laparoscopy represents an alternative to open surgery for virtually all digestive surgery procedures, with the anticipated short-term advantage of reduced esthetic prejudice, postoperative pain, and duration of in-hospital stay. In this study, we investigated the safety and benefits of laparoscopic liver resections in patients with benign solid liver tumors. Methods: Laparoscopic liver resection of up to two segments for benign liver tumor was performed under continuous carbon dioxide (CO₂) pneumoperitoneum in 21 patients with no underlying chronic liver disease. The risk of gas embolism was assessed by end-tidal CO₂ and O₂ saturation, and the hemodynamic variations were monitored by a Swan-Ganz catheter. The postoperative course was compared with that following open surgery by matched-pair analysis. Results: No patient experienced gas embolism or was converted, and clamping of the hepatic pedicle resulted in hemodynamic variations comparable to those observed during open surgery. Duration of surgery (177 vs 156 min.), intraoperative blood loss (218 vs 285 ml), modifications of postoperative liver function tests, and incidence of postoperative complications (10% vs 10%) were comparable to those after open surgery. Laparoscopic resection was associated with a 50% reduction (15.5 vs 31.6 mg) in morphine consumption during the first postoperative days, a reduction of the delay to oral intake of 0.8 days, and a reduction of in-hospital stay of 1.4 days. Conclusions: Liver resections of up to two segments can be performed by laparoscopy using the same technique as that used during open surgery. However, the benefits observed compared with open surgery appear to be limited. Received: July 25, 2001 / Accepted: January 5, 2002     

Molecular mechanisms underlying postoperative peritoneal tumor dissemination may differ between a laparotomy and carbon dioxide pneumoperitoneum: a syngeneic mouse model with controlled respiratory support

Background  The mechanisms promoting postoperative peritoneal tumor dissemination are unclear. This study aimed to investigate postoperative tumor dissemination over time on both tissue and molecular levels. Methods  For this study, C57BL6 mice were randomized into four groups: anesthesia alone (control), carbon dioxide (CO₂) pneumoperitoneum at low (2 mmHg) or high (8 mmHg) intraperitoneal pressure (IPP), and laparotomy. A mouse ovarian cancer cell line (ID8) was injected intraperitoneally just before surgery. The groups were further subdivided into three groups, and a laparotomy was performed to evaluate tumor dissemination on postoperative day (POD) 7, 14, or 42. Results  The incidence of cancer cell invasion into the muscle layers of the abdominal wall was significantly higher in the laparotomy and high-IPP groups than in the low-IPP and control groups on PODs 7 and 42. Expression levels of beta 1 integrin, cMet, urokinase-type plasminogen activator (uPA), urokinase-type plasminogen activator receptor (uPAR), and type-1 plasminogen activator inhibitor (PAI-1) mRNA in the disseminated nodules were not significantly different among the four groups on POD 7. However, the expression levels of all these genes in the disseminated nodules in the laparotomy group were significantly higher on POD 14 than on POD 7. They then returned to control levels on POD 42. There were no significant differences in the expression levels of any of these genes among the groups on POD 42. Conclusions  The current study suggests that the molecular mechanisms underlying postoperative peritoneal tumor dissemination may differ between a laparotomy and CO₂ pneumoperitoneum. Therefore, strategies targeting postoperative tumor dissemination likely will need to account for the surgical environment.     

Concordancia entre las ecuaciones de estimación del filtrado glomerular y el aclaramiento de creatinina en orina de 4 horas en pacientes críticos con trauma grave

Background and objectiveThere is a growing body of evidence that the equations used to estimate the glomerular filtration rate (GFR) are not suitable in critically ill patients, a population whose GFR fluctuates continuously. Glomerular filtration is usually estimated by measuring urine creatinine clearance (CrCl) at various time points. The aim of our study was to evaluate the performance of the most widely used GFR calculators in the subpopulation of critically ill patients admitted for severe trauma, and to compare the results against determinations of CrCl in urine collected over a 4-hour period (4h-CrCl).Material and methodsObservational study in patients hospitalized for severe trauma. We measured the 4h-CrCl and estimated GFR using the Cockcroft-Gault, modified Jelliffe, MDRD, t-MDRD, and CKD-EPI equations, adjusting the results for body surface area (BSA) (ml/min/1.73m²). Data were analysed using R version 4.0.4.ResultsA total of 85 patients were included. Median age was 51 years, and 68 were men (78.82%). The mean BSA-adjusted 4h-CrCl (4h-ClCr/1.73 m²) was 84.5 ml/min/1.73 m². We found that GFR estimated using the t-MDRD equation correlated significantly with 4h-CrCl/1.73 m². The Cockcroft-Gault equation correlated significantly with 4h-CrCl/1.73 m² when GFR was greater than 130 ml/min/m².ConclusionsIn ICU patients, glomerular filtration can be reliably estimated by determining urine CrCl, but GFR calculators are not accurate in this population.     

An audit of 24-hour creatinine clearance measurements at Tygerberg Hospital and comparison with prediction equations.

BACKGROUND: Internationally, clinical guidelines recommend the use of creatinine-based equations to estimate glomerular filtration rate (GFR) for assessment and follow-up of kidney disease. The routine use of 24-hour creatinine clearances (CrCl) is no longer advocated. OBJECTIVES: To examine the indications for requesting CrCl at Tygerberg Hospital, identify problems associated with the procedure, and evaluate the utility of the Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations with different levels of renal dysfunction in the ethnic groups of the Western Cape. METHODS: A clinical audit of CrCl was performed. The estimated GFR as predicted by the modified CG and MDRD formulae was compared with CrCl in 252 patients, representing three local ethnic groups. MDRD formulae with and without the correction factor for black ethnic group (MDRD-B) were evaluated. RESULTS: Problems with urine collection or data supplied were identified in one-third of CrCl requests, leading to unreliable results. The CG correlated best with CrCl in the group as a whole. The average absolute and percentage differences from CrCl in the different ethnic groups were as follows: coloured (mixed ethnicity) (N = 186) - CG 13.4 ml/min/1.73 m(2) (18%), MDRD 16.8 ml/min/1.73 m(2) (23%) and MDRD-B 27.9 ml/ min/1.73 m(2) (38%); black (N = 21) - CG 14.8 ml/min/1.73 m(2) (19%), MDRD 12.9 ml/min/1.73 m(2) (17%) and MDRD-B 25.1 ml/min/1.73 m(2) (33%); white (N = 45) CG 13.5 ml/min/1.73 m2 (19%), MDRD 15.3 ml/min/1.73 m(2) (21%) and MDRD-B 24.8 ml/min/1.73 m(2) (35%). Throughout the renal function levels (chronic kidney disease stages 1 - 5) CG correlated better with CrCl than MDRD. CONCLUSIONS: Possible reasons for poor correlations include a high prevalence of obesity, underweight and normal GFR in the study population. There is a need for further research, using a gold standard, into the accuracy of these prediction equations in our unique patient populations before firm recommendations can be made regarding their use. Until then CrCl will continue to be widely used. Greater efforts at patient and health care worker education are required to ensure proper collections.     

Impact of surgical peritoneal environment on postoperative tumor growth and dissemination in a preimplanted tumor model

Background  We recently demonstrated that CO₂ pneumoperitoneum at low intraperitoneal pressure (IPP) had few if any short-term effects on peritoneal dissemination when an ovarian cancer cell line was inoculated just prior to surgery. The objective of the present study was to evaluate the impact of surgical peritoneal environment on postoperative tumor growth and dissemination over time when tumors were present before surgery. Methods  On day-7, C57BJ6 mice received an intraperitoneal inoculation of a mouse ovarian cancer cell line (ID8). On day 0, mice were randomized into four groups: anesthesia alone, CO₂ pneumoperitoneum at a low (2 mmHg) or high (8 mmHg) IPP, or laparotomy. Groups were further subdivided into four groups of eight animals each and a laparotomy was performed to evaluate dissemination on postoperative day (POD) 1, 2, 7 or 14. Results  Peritoneal dissemination score was significantly higher in the laparotomy group compared with in the remaining three groups on PODs 2 and 7. We detected no significant differences in the peritoneal dissemination scores among the low-IPP, high-IPP, and anesthesia groups on PODs 2 and 7. However, there were no significant differences in the peritoneal dissemination score among the three surgical groups on POD 14. Histopathological examination demonstrated that the incidence of invasion of cancer cells into the muscle layers was significantly higher in the laparotomy group than in the low-IPP and anesthesia groups on POD 14. There were no significant differences in tumor growth among the four groups. Conclusions  The present findings suggest that CO₂ pneumoperitoneum at either high or low IPP has few if any short-term effects on peritoneal dissemination when tumors are well established before surgery. This study was supported in part by la Ligue Régionale de Lutte contre le Cancer (Auvergne region, France) and Karl Storz Endoscopy GmbH (Tuttlingen, Germany).     

The correlation between preoperative renal scintigraphy and postoperative renal function in upper urinary tract urothelial carcinoma patients following radical nephroureterectomy

ObjectiveTo predict the renal function after nephroureterectomy (NUR) for upper urinary tract urothelial cancer (UTUC) based on preoperative technetium-99m mercaptoacetyltriglycine (99mTc-MAG3) renal scintigraphy.Subjects and methodsWe retrospectively reviewed 238 patients who originally underwent nephroureterectomy for UTUC between 2007 and 2010. Of these patients, 129 underwent MAG3 renal scintigraphy before unilateral NUR. Serum creatinine was measured in all of the patients before surgery, and renal function was monitored for one year after surgery. Preoperative and postoperative eGFRs were compared and analyzed based on the preoperative MAG3 renal scintigraphy.ResultsA total of 129 patients, including 62 men (48%) and 67 women (52%) with an average age at surgery of 69.0 years (range from 48 to 87) were included in this study. The mean preoperative creatinine level was 1.42 mg/dL, and the baseline eGFR was 54.76 ml/min/1.73 m². One year after NUR, the mean creatinine level was 1.89 mg/dL, and the eGFR was 44.44 ml/min/1.73 m², a mean decrease of 18.73%. The preoperative effective renal plasma flow (ERPF) of the operated kidney was 91.65 ml/min/1.73 m², and that of the remaining kidney 158.30 ml/ min/1.73 m². The average preoperative ERPF of the resected kidney accounted for 34% of total preoperative ERPF, which was statistically significant in its relation to the decrease in eGFR. The decrease in eGFR ratio was also significantly correlated with the calculated decrease in ERPF ratio (R² = 0.279, p < 0.001). The predictive equation of renal function one year after NUR was established as following: eGFR decreased ratio = –0.80 × predictive ERPF decreased ratio +0.72.ConclusionWe developed an equation to predict postnephroureterectomy 1 year eGFR before surgery based on preoperative MAG3 renal scintigraphy results and preoperative eGFR. The equation could be more accurate in the situation if the diseased kidney is not hydronephrotic.     

Laparoscopic cholecystectomy using abdominal wall retraction

Background: Disadvantages related to CO₂ pneumoperitoneum have led to development of the abdominal wall retractor (AWR), a device designed to facilitate laparoscopic surgery without conventional pneumoperitoneum (15 mmHg CO₂). We investigated the effects of the AWR on hemodynamics and gas exchange in humans. We also investigated whether the use of an AWR imposed extra technical difficulties for the surgeon. A pilot study revealed that cholecystectomy without low-pressure pneumoperitoneum was technically impossible. Methods: A prospective randomized controlled trial: Twenty patients undergoing laparoscopic cholecystectomy were randomly allocated into group 1: AWR with low-pressure pneumoperitoneum (5 mmHg), or group 2: conventional pneumoperitoneum (15 mmHg). Results: Surgery using the AWR lasted longer, 72 ± 16 min (mean ± SD) vs 50 ± 18 min compared with standard laparoscopic cholecystectomy. There were no differences between the groups with respect to hemodynamic parameters, although a small reduction of the cardiac output was observed using conventional pneumoperitoneum (from 3.9 ± 0.7 to 3.2 ± 1.1 l/min) and an increase during AWR (from 4.2 ± 0.9 to 5.2 ± 1.5 l/min). Peak inspiratory pressures were significantly higher during conventional pneumoperitoneum compared to AWR. A slight decrease in pH accompanied by an increase in CO₂ developed during pneumoperitoneum and during the use of the AWR. In both groups arterial PO₂ decreased. Conclusions: The results indicate that the view was impaired during use of the AWR and therefore its use was difficult and time-consuming. Possible advantages of this devices' effects on hemodynamics and ventilatory parameters could not be confirmed in this study.     

腹腔镜胆囊切除术与腹腔镜妇科手术中麻醉、体位、CO2气腹对血流动力学及呼吸动力学影响的比较研究

目的:观察腹腔镜胆囊切除术(LC)与腹腔镜妇科手术中麻醉、体位、CO2气腹对血压、心率、SpO2、PetCO2、气道压的影响。方法:选择ASAⅠ~Ⅱ级择期行腹腔镜胆囊切除术,腹腔镜妇科手术病人各38例,予以异丙酚、异氟醚维持麻醉,分别于诱导前、插管后即刻、插管后5min、气腹后3min、8min及气腹放气后平卧位记录血流动力学及呼吸动力学参数。结果:两组插管后5min血压、心率明显低于诱导前;气腹后3min、8min血压、PetCO2、气道压明显高于插管后5min(P<0.01)。两组之间相比,妇科手术气道压、PetCO2显著高于LC组(P<0.01)。结论:腹腔镜妇科手术呼吸动力学的改变明显大于LC组,血流动力学改变两组间无显著差异。