Intraoperative catheter management during laparoscopic excision of a giant bladder diverticulum

BACKGROUND: Massive bladder diverticula present a technical challenge to the laparoscopic surgeon. We describe a laparoscopic approach to transperitoneal diverticulectomy, using a specific catheter arrangement to allow excellent control of the various portions of the procedure. METHODS: A 49-year-old male with longstanding frequency was diagnosed with a 1000 cc bladder diverticulum and bladder neck outlet obstruction. Laparoscopic transperitoneal diverticulectomy was performed using a triple catheter arrangement: endoscopic placement of a Councill catheter in the diverticulum, fluoroscopic positioning of an occlusion balloon catheter in the renal pelvis, and placement of a Cope loop suprapubic tube. Additionally, a transurethral incision of the prostate was performed. RESULTS: The procedure was completed laparoscopically using a four port transperitoneal approach. During the procedure, the diverticulum could be filled and emptied as needed; the catheter across the diverticular neck facilitated subsequent closure of the bladder wall defect. The diverticulum was completely excised. The remaining defect in the bladder was then closed in 2 layers. The patient was discharged on postoperative day 3. CONCLUSION: Careful planning and arrangement of catheters in the bladder, ureter, and diverticulum facilitates laparoscopic transperitoneal diverticulectomy of even a very large volume diverticulum.     

The two-pore-domain K(+) channels TREK-1 and TASK-3 are differentially modulated by copper and zinc

The "trace" elements copper and zinc are essential for life, and their role in the function of metalloproteins is well known. However, mounting evidence shows that these metals are also capable of modulating neuronal excitability under normal physiological conditions. They are present at high levels in the brain, are concentrated at nerve terminals, and are released at micromolar concentrations into the synaptic cleft after depolarization. They have been shown to affect the function of a number of different voltage- and ligand-gated ion channels, but their most important targets in the nervous system remain uncertain. In this study, we show that the two-pore-domain potassium channels TREK-1 and TASK-3 are potently modulated by both copper and zinc. Copper activates TREK-1 channels by 83 +/- 11% with an EC(50) of 3.0 +/- 1.0 microM, whereas TASK-3 channels are potently inhibited, with an IC(50) of 2.7 +/- 0.4 microM. Zinc inhibits both channels but with very different affinities. The IC(50) for inhibition of TREK-1 channels is 659 +/- 94 microM whereas the IC(50) for inhibition of TASK-3 is 12.7 +/- 1.0 microM. Using site-directed mutagenesis, we show that Asp128 plays a critical role in the copper activation of TREK-1. These observations provide a novel explanation for how copper and zinc might affect neuronal excitability under both normal physiological conditions, as well as during diseases in which copper or zinc homeostasis has been disrupted.     

Single-center comparison of purely laparoscopic,hand-assisted laparoscopic,and open radical nephrectomy in patients at high anesthetic risk

BACKGROUND AND PURPOSE: The laparoscopic approach for management of high-risk patients with renal-cell carcinoma (RCC) may reduce perioperative and postoperative morbidity. The aim of this study was to compare the outcome of purely laparoscopic radical nephrectomy (LRN), hand-assisted laparoscopic radical nephrectomy (HALRN), and open radical nephrectomy (ORN) for renal tumors in a population of patients at high risk for perioperative complications. PATIENTS AND METHODS: All patients undergoing radical nephrectomy for presumed RCC between August 1999 and August 2001 at Vanderbilt University Medical Center and having an American Society of Anesthesiologists (ASA) score of >/=3 were reviewed. Patients with known metastasis, local invasion, caval thrombi, or additional simultaneous surgical procedures were excluded from analysis. Thirteen patients underwent LRN, eight patients underwent HALRN, and 26 underwent ORN. The patient demographics were similar in the three groups. The groups were compared with regard to intraoperative and postoperative parameters. Statistical analysis was done using chi-square testing for categorical variables and analysis of variance (ANOVA) for continuous variables. Differences in outcomes were examined using ANOVA and Dunnett's T for pairwise comparisons. RESULTS: The ASA 4 patients had significantly longer hospital stays and total hospital costs than the ASA 3 patients. The mean operative time in the ASA 3 patients was similar in the three groups: 2.8 hours, 2.8 hours, and 2.5 hours for the LRN, HALRN, and ORN patients, respectively. Both the LRN patients (22.9 mg of morphine sulfate equivalent) and the HALRN patients (42.1 mg) required less pain medication than the open surgery patients (97.7 mg). When the total hospital costs were compared, LRN was less costly than HALRN ($6089 v $7678; P = 0.57) and open surgery ($6089 v $7694; P = 0.04). The complication rate in the LRN, HALRN, and ORN group was 0%, 25%, and 27%, respectively, although the differences were not statistically different (P = 0.12). CONCLUSIONS: Both LRN and HALRN can be performed safely in patients with significant comorbid conditions. Careful preoperative preparation, intraoperative monitoring, and awareness of laparoscopy-induced oliguria can preclude inadvertent overhydration, hemodilution, and congestive heart failure. Both LRN and HALRN result in less pain medication requirement and faster return to oral intake than ORN, and LRN results in fewer perioperative complications than HALRN or ORN in patients at high perioperative risk. The LRN technique has a 21% lower total cost than both HALRN and ORN.     

Laparoscopic cyst decortication in autosomal dominant polycystic kidney disease: impact on pain,hypertension, and renal function

BACKGROUND AND PURPOSE: In patients with autosomal dominant polycystic kidney disease (ADPKD), laparoscopic cyst decortication (LCD) has been proposed as a means to relieve chronic cyst-related pain. We present our 7-year experience with LCD for ADPKD with regard to pain relief, hypertension, and renal function. PATIENTS AND METHODS: Between August 1994 and February 2001, 29 ADPKD patients with chronic pain (N=29), hypertension (N=21), and renal insufficiency (N=10) underwent 35 LCD procedures. Every detectable cyst within 2 mm of the renal surface was treated. Pain relief was assessed using a pain analog scale; relative pain relief (RPR) equaled (preoperative pain score) - (postoperative pain score)/(preoperative pain score). Hypertension was evaluated using the antihypertensive therapeutic index (ATI): [(dose of blood pressure medication 1/max dose 1) + (dose med 2/max dose 2) + etc.] x 10. Renal function was assessed using the Cockcroft and Gault formula for creatinine clearance. RESULTS: The mean operating room time was 4.9 hours (range 2.6-6.6 hours) with no conversions to open surgery. An average of 220 cysts (range 4-692) were treated per patient. The mean follow-up was 32.3 months (range 6-72 months). The RPR was 58%, 47%, and 63% at 12, 24, and 36 months, respectively. At 12, 24, and 36 months, 73%, 52%, and 81% of patients, respectively, noted >50% improvement in their pain compared with the preoperative situation. Five patients became normotensive, and patients improved their ATI by an average of 49% (range 11%-93%). However, six patients had worsening hypertension, with an ATI increase averaging 53% (range 11%-122%), and one patient who was not hypertensive preoperatively has since developed hypertension. The creatinine clearance changed +4%, +7%, and -2% at 12, 24, and 36 months, respectively. Only one patient had a >20% increase in creatinine clearance. The only patients with a >20% decrease in creatinine clearance were those who had a creatinine clearance <30 mg/dL preoperatively (average decrease 34% [range 20%-51%]). CONCLUSIONS: For ADPKD patients with debilitating pain, extensive LCD can provide durable relief. In the majority of patients with pain and hypertension, a marked improvement in blood pressure also occurs. Cyst decortication was not associated with worsening renal function; indeed, renal function remained largely unchanged over the 3-year follow-up period.     

Hepatic and mesenteric nitric oxide synthase expression in a rat model of CCl(4)-induced cirrhosis

BACKGROUND: Cirrhosis and portal hypertension are frequently linked with changes in expression of nitric oxide synthase (NOS) and/or endotoxaemia. AIMS: This study tested the following hypothesis: that inducible (i)NOS activity is increased within the visceral circulation concurrently with decreased constitutive (c)NOS activity in the hepatic sinusoids and that the concentration of NO metabolites in portal blood is consequent on endotoxin concentration. MATERIALS AND METHODS: Plasma concentrations of (nitrite + nitrate) and endotoxin, together with hepatic and mesenteric NOS activity (arginine/citrulline method) and protein expression (histochemistry) plus portal and arterial blood pressure, were determined in rats made severely cirrhotic by intragastric CCl(4) over 14 weeks (n = 6) compared with age-matched controls (n = 5). The concentrations of [nitrite + nitrate] and endotoxin in portal plasma were also directly compared in rats made cirrhotic for a period of 8-14 weeks (n = 10). RESULTS: In rats with advanced cirrhosis, arterial [nitrite + nitrate] was 93.1 (22.4) micromol/L (mean, SEM) compared with 29.1 (6.1) micromol/L in controls (P < 0.05); portal plasma [NO(2)(-) + NO3(-)] was 127.1 (27.2) compared with 24.7 (4.7) micromol/L in controls (P < 0.05). Cirrhotic rats had higher endotoxin concentration in plasma compared with controls (systemic: 85.0 (24.5) versus 1.7 (0.2) EU/ml, P < 0.05; portal: 180.3 (47.9) versus 1.7 (0.2) EU/ml, P < 0.05). The same severely cirrhotic rats possessed decreased cNOS activity in liver (2.95 [0.40] versus 5.29 [0.85] pmol/min/g; P < 0.05) and increased iNOS activity in mesentery (4.83 [1.23] versus 1.47 [0.15] pmol/min/g; P < 0.05) compared with controls. Histochemical observations confirmed these findings. Rats given CCl(4) for a period of 8-14 weeks possessed high endotoxin concentration in portal plasma, with correspondingly high [nitrite + nitrate] (r(2) = 0.954; P < 0.001). CONCLUSIONS: An endotoxin-induced increase in mesenteric iNOS activity and a decrease in hepatic cNOS activity may account for, respectively, the hyperdynamic visceral circulation and the increased intrahepatic resistance of cirrhosis.     

Simultaneous detection of apoptosis and proliferation in colorectal carcinoma by multiparameter flow cytometry allows separation of high and low-turnover tumors with distinct clinical outcome

BACKGROUND: Dukes C colorectal carcinoma is treated with adjuvant chemotherapy. Adjuvant treatment is not standard for patients with Dukes B tumors, even though about 20% of patients within this tumor stage die of recurrent disease. The authors investigated whether a novel method of simultaneous detection of apoptosis and proliferation would improve the assessment of prognosis in colorectal carcinoma patients, with the ultimate goal of accurately identifying patients eligible for adjuvant therapy. METHODS: A multiparameter flow cytometric assay with heat pretreatment was performed on 278 paraffin-embedded colorectal adenocarcinomas. After immunochemical isolation of tumor cells, apoptosis and proliferation were assessed simultaneously by immunostaining for the M30 antibody and by quantitative DNA analysis, respectively. Patients were followed for more than 10 years. RESULTS: The mean values of apoptosis (apoptotic fraction [AF], i.e., the percentage of M30-positive cells) and proliferation (S-phase fraction [SPF]) were 11.1% and 13.1%, respectively. The AF and SPF values were correlated positively (P = 0.01) and both increased with advancing tumor stage (P = 0.02). Combining AF and SPF, patients with tumors with a high turnover (i.e., both AF and SPF values were greater than the mean) had an overall survival rate of 13%, whereas patients with low-turnover tumors (i.e., both AF and SPF values were less than the mean) had an overall survival rate of 89% (P < 0.001 by log rank test). Moreover, within Dukes B and C stages, patients with high-turnover tumors had a poorer survival than patients with low-turnover tumors (P < 0.001 for both stages). CONCLUSIONS: The simultaneous detection of apoptosis and proliferation in archival material allows separation of high and low-turnover colorectal adenocarcinomas and improves the assessment of prognosis. This technique could be used to stratify patients for adjuvant chemotherapy.     

Longevity of batteries in internal pulse generators used for deep brain stimulation

The longevity of batteries in internal pulse generators (IPGs) used clinically for deep brain stimulation is not known. We conducted a study to assess the life span of these batteries. From 1993 to 2000, 163 single-channel batteries were surgically implanted in our institution. The electrical settings utilized in patients who had battery failures were assessed and the total electrical energy delivered (TEED) was calculated and correlated with battery longevity. Fourteen IPGs had battery failure requiring replacement. The median life span of the batteries was 45 months. Batteries with high energy consumption as assessed by TEED had a reduced life span (r = -0.82, p < or = 0.001). Patients with essential tremor who required battery replacement needed higher settings to control their symptoms and therefore presented a shorter battery life when compared to patients with Parkinson's disease. In our series of patients who needed battery replacement, battery longevity varied with stimulation parameters but was longer than expected from the manufacturer's specifications.