Impact of Arterial and Arteriovenous Renal Clamping with and without Intrarenal Cooling on Renal Oxygenation and Temperature in a Porcine Model
Bibliographic record
Abstract
BACKGROUND: As laparoscopic partial nephrectomy increases in prominence, more needs to be understood about the combined effect of the pneumoperitoneum and renal ischemia during tumor resection. The purpose of this study is to investigate the effect of combined renal hilar clamping (arterial only versus arteriovenous) and retrograde intrarenal cooling on renal temperature and oxygenation in a porcine laparoscopic partial nephrectomy model. MATERIALS AND METHODS: Under general anesthesia, laparoscopic access with intra-abdominal pressure of 15 mm Hg to the left renal hilum was obtained. Licox tissue oxygenation and temperature probes were placed into the kidney transcutaneously; measurements were taken every 30 seconds. After establishing baseline readings, either the artery alone (n=18) or the artery and vein (n=18) were clamped for 30, 60 or 90 minutes (n=12 each). During vascular clamping, retrograde, intrarenal cooling was performed with ice cold saline infused via a percutaneously placed ureteric catheter in 18 pigs. Changes in renal pO2 and temperature were analyzed with repeated measures ANCOVA in SPSS 16. RESULTS: Retrograde cooling decreased renal parenchyma to 75.8% of baseline temperature (27.9 degrees C) within 15 minutes. There were no differences in cooling whether arterial or arteriovenous clamping was used (p=0.79). In uncooled animals, there was no significant difference in the decrease in renal pO2 during the clamp phase (p=0.18) or during the recovery phase (p=0.52). During the recovery phase, renal pO2 in uncooled animals was significantly higher than in those who received cooling (p=0.01). Animals who underwent hilar clamping for extended periods (60 and 90 min) had a slower recovery of renal pO2 to baseline than those with hilar clamping for 30 minutes (p=0.04) CONCLUSION: Retrograde intrarenal cooling can reliably cool the porcine kidney to 28 degrees C, regardless of whether arterial or arteriovenous clamping is used. Renal pO2 is not significantly different between animals that undergo artery only versus en bloc hilar clamping. Pigs that were provided with retrograde cooling had a slower return of pO2 to baseline following release of hilar clamps, possibly due to hypothermic vasospasm. Clamp durations greater than 60 minutes were also associated with slower return of renal oxygenation to baseline.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".