Variable mechanisms were suggested to mediate the changes in renal hemodynamics during pneumoperitoneum. To assess whether it can be pressure dependent only, we conduct a study in an isolated, pressurized, and perfused organ model.
Seventy Wistar rat kidneys were perfused with oxygenated, 3% albumin-contained Krebs-Henseleit solution. Experiments took place within Plexiglass chamber that provided conditions for perfusion of organs, humidity, and maintenance of intracameral CO2 pressures [0 (control), 3, 5, 8, 12, 15, and 18 mm Hg]. All kidneys (10/group) were perfused for 60 minutes. One-half of the groups were perfused for an additional 30 minutes, during which the perfusion pressures were reduced to 0 mm Hg. pH of the perfusate was measured as well.
The perfusion pressure increased and the kidney flow decreased slightly, in proportion with the intrachamber pressure. Urine output decreased to a minimum of 40% in >or=8 mm Hg pressure conditions, compared with the control group. The pH values were below normal, during experimental pneumoperitoneum.
Pneumoperitoneal conditions are a direct cause of changes in renal urinary output. The increase in pCO2 pressure and consequently low intraorgan pH may contribute to a mild transient renal damage during pneumoperitoneum.
"In a study conducted by Ozmen et al. in 2009 on 40 rabbits, effects of different Co2 gas pressures were examined on inflammatory, cytokine levels and free-radicals responses during Co2 Pneumoperitoneum, and it was found that gas pressures: 10, 15 and 20 mmHg cause ischemia, release of reactive oxygen species and cytokinesmediated cell damage (Ozmen, Zulfikaroglu et al. 2009). Other studies have shown that CO 2 pneumoperitoneum causes increased level of prostate-specific antigen and renal damage (Khoury, Szold et al. 2008, Turkmenoglu, Bozlu et al. 2010). However, some studies have shown that with well-controlled gas pressure, adverse effects on hemodynamic parameters can be avoided (Gründel, Böhm et al. 1998, Andersson, Lagerstrand et al. 2002). "
[Show abstract][Hide abstract] ABSTRACT: This study aimed to investigate the effect of different pressures of CO2 on expression of P33 gene
and apoptosis in liver and spleen cells during CO2 pneumoperitoneum. In this study, 30 male
Sprague-Dawley rats, weighing approximately 280-340 grams were procured from Tehran Pasteur
Institute’s animal house, and randomly divided into 3 equal groups of 10 each. Groups 1 and 2
received 10 and 20 mmHg respectively, and group 3 was the control group. CO2 was insufflated
into abdominal cavity of rats in groups 1 and 2 for one hour using a cannula, and then, perfusion
was performed for half an hour. In group 3, cannula was placed into abdominal cavity without
releasing any gas. The rats were sacrificed afterwards, and their livers and spleens were removed
after laparotomy to investigate expression of gene P33 and apoptosis using RT-PCR and TUNEL
techniques. The TUNEL technique showed a significant increase in apoptosis in liver and spleen
cells of rats that received 20 mmHg compared to rats that received 10 mmHg and control group
(P<0.0001) and (P<0.006).respectively. Furthermore, RT-PCR revealed a significant decrease in
P33 gene mRNA in liver and spleen cells in 20 mmHg group compared to other two groups
(P<0.001). Too high a pressure or too long a duration of CO2 gas may cause release of cytokines
and free-radicals from cells of these organs, which can lead to transient or serious dysfunction.
[Show abstract][Hide abstract] ABSTRACT: Purpose: We report a new method of tumor exposure through a minilaparotomy window and cold ischemia using a LapSac® during partial nephrectomy by video-assisted minilaparotomy surgery (VAMS). Materials and Methods: Partial nephrectomy was performed by VAMS in a total of 31 patients during a period ranging from January 2004 to June 2006, and tumor exposure and cold ischemia were achieved by using a LapSac®. We investigated the tumor size and location, mean operative time, mean estimated blood loss, mean cold ischemic time, and pathologic outcomes retrospectively. We evaluated preoperative and postoperative renal function with the estimated creatinine clearance rate by the MDRD equation. Results: The mean tumor size was 2.59±1.30 cm and mean surgical time was 182.5±44.5 minutes. Mean cold ischemic time was 31.84±8.43 minutes. Mean estimated blood loss was 445.65±202.77 ml (range, 100-800 ml), and 3 patients required transfusion. A histopathologic examination confirmed a diagnosis of renal cell carcinoma in 22 patients (71%). The surgical margin was positive in 1 patient. Twenty-one patients had a mean followup of 53±8.19 months. Nineteen patients survived without any disease recurrence, 1 patient survived with lung metastasis within 5 months, and 1 patient died of unrelated cause. There was no significant difference between the preoperative and postoperative estimated creatinine clearance rate by using the MDRD equation. Conclusions: Tumor exposure and cold ischemia were attempted in a partial resection of the kidney by VAMS with a LapSac®. This technique for partial nephrectomy by VAMS might be an effective, safe modality.
Korean journal of urology 08/2009; 50(8). DOI:10.4111/kju.2009.50.8.774
[Show abstract][Hide abstract] ABSTRACT: Aiming the principles of open partial nephrectomy, warm ischemia time is the limiting factor especially in case of central or complex tumors in laparoscopy. We demonstrate a novel solely laparoscopic technique for in situ cold perfusion of kidneys with direct catheterization of the renal artery to increase the tolerance of renal parenchyma for ischemia.
In two patients with hilus compromising tumors, renal artery was clamped; a small incision in the artery was used to place a 5Fr centrally open angiographic balloon catheter and blocked with 1 ml NaCl. The kidney was perfused with 4°C Ringer solution. After tumor excision, the kidney was subsequently reconstructed by mattress bolster sutures and fibrin glue. The arterial incision was closed by a 4/0 Prolene suture.
Both patients had an uneventful follow-up without neither intraoperative nor postoperative complications. No intraoperative body temperature drop occurred. Cold ischemia time was 66 (men, 65a) and 60 min (women, 43a), respectively. Hemoglobin drop was 4.1 and 1.9 g/dl; no transfusion was necessary. Preoperative and postoperative creatinine levels were 0.90 and 0.76 mg/dl, and 1.3 and 0.9 mg/dl, respectively. Patients were discharged on day 12 and day 8. Histology revealed clear cell RCC (pT1b pNx pMx G2 R0) in the first patient and oncocytoma in the second patient. Postoperative CT angiograpy demonstrated no sign of arterial insufficiency.
Intraarterial renal cooling could expand the ischemia time and therefore the indication of laparoscopic partial nephrectomy in complex exposition. Furthermore, the identification of tumor borders and injured vessels is facilitated by the outflow of the cooling solution. Further investigations into this promising method could proof its feasibility in everyday clinical routine.
World Journal of Urology 10/2010; 29(3):337-42. DOI:10.1007/s00345-010-0597-4 · 2.67 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.