Preoperative planning system for surgical robotics setup with kinematics and haptics

Recently, some useful robotic surgical systems have been developed and applied in many surgical situations. Systems such as the da Vinci surgical system of Intuitive Surgical Inc., which facilitates minimally invasive surgery with increased dexterity, are commercially available. Preoperative simulation and planning of surgical robot setups should accompany advanced robotic surgery if their advantages are to be further pursued. Feedback from the planning system will play an essential role in computer-aided robotic surgery in addition to preoperative detailed geometric information from patient CT/MRI images. Surgical robot setup simulation systems for appropriate trocar site placement have been developed especially for abdominal surgery. The motion of the surgical robot can be simulated and rehearsed with kinematic constraints at the trocar site, and the inverse-kinematics of the robot. Results from simulation using clinical patient data verify the effectiveness of the proposed system.     

How successful is the conservative management of pelvi‐ureteric junction obstruction in adults?

OBJECTIVE

To assess the conservative management of pelvi‐ureteric junction obstruction (PUJO), according to severity, accepted in paediatric urology but rarely reported in adults.

PATIENTS AND METHODS

A series of 23 patients (median age 58 years, 17 men and six women) with asymptomatic or minimally symptomatic PUJO were managed conservatively. The patients’ age, preference and comorbidities were considered. The diagnosis of PUJO was based on intravenous urography and isotopic renography. After stringently reviewing the renograms based on relative renal function (RRF) and output efficiency (OE), 15 patients had an OE consistent with definitive PUJO. One patient had no further imaging due to associated comorbidities. Ten patients had right PUJO, three left and one with bilateral PUJO, with unilateral conservative management. The follow‐up included annual renography and clinical consultation. Laparoscopic pyeloplasty was considered for patients with a >10% loss of RRF and/or <40% RRF during the follow‐up.

RESULTS

Overall, 14 of 15 patients had renograms during the follow‐up. The mean RRF of the affected kidney at diagnosis was 48.6% which marginally decreased to 46.7% after a median (range) follow‐up of 44 (23–75) months. The RRF of 11 patients remained stable and in three decreased significantly (median 11% RRF), requiring pyeloplasty. None of the patients became symptomatic throughout the follow‐up.

CONCLUSION

In asymptomatic adults the conservative management of PUJO appears to be safe during a short‐ to medium‐term follow‐up. We recommend that patients are regularly followed with renography and seen promptly should they become symptomatic. A longer follow‐up is needed in a larger group to confirm these findings.     

A critical assessment of the prognostic value of clear cell,papillary and chromophobe histological subtypes in renal cell carcinoma: a population‐based study

OBJECTIVE

To assess the magnitude of the effect of histological subtype (HS, the three most common being clear cell, papillary and chromophobe) on cause‐specific mortality (CSM) from renal cell carcinoma (RCC).

PATIENTS AND METHODS

Univariable and multivariable Cox regression models included data from 11 618 patients treated with nephrectomy between 1988 and 2004 in nine Surveillance Epidemiology and End Results registries. We tested whether HS represents an independent predictor of CSM, and whether HS adds to the ability of other variables to predict CSM. The covariates comprised age, year of surgery, T stage, nodal status, M stage and Fuhrman grade.

RESULTS

In a multivariable model predicting CSM, HS was an independent predictor (P = 0.03), but failed to improve the accuracy of the model (+0.1% gain when HS was included in the model).

CONCLUSION

Although we confirmed that HS is an independent predictor for CSM, there was no gain in accuracy when HS was added to standard predictors of CSM. From a practical perspective, this implies that patients with clear cell, papillary and chromophobe HS share similar natural histories after nephrectomy, provided that other cancer characteristics are accounted for. From a statistical perspective, in multivariable models of CSM, the clear cell, papillary and chromophobe HS might be included as a single entity.     

Bladder outlet obstruction accelerates bladder carcinogenesis

OBJECTIVE

To examine the correlation between partial bladder outlet obstruction (PBOO) and bladder carcinogenesis.

MATERIALS AND METHODS

Female Wistar rats (6 weeks old) were divided into three groups of 10 each: group 1 was exposed to n‐butyl‐n‐butanol nitrosamine (BBN, a carcinogen) in drinking water for 8 weeks; group 2 had PBOO induced surgically after exposure to BBN for 8 weeks; group 3 had a sham operation and the rats drank normal water (control group). After 20 weeks, all of the rats were killed humanely and their bladders analysed.

RESULTS

There were no significant differences in body weight among the groups. The bladder weight of group 2 was significantly greater than either group 1 or group 3. Histopathologically, bladder smooth muscle hypertrophy was the major cause of the increased bladder weight for group 2. In group 2 there were increases in bladder wall thickness and many nipple‐shaped urothelial tumours. Basic fibroblast growth factor and hypoxia‐inducible factor‐1α expression were significantly greater in group 2 than in groups 1 and 3.

CONCLUSIONS

Exposure of the bladder to carcinogens during bladder hyperplasia and hypertrophy induced by PBOO results in a greater incidence of superficial bladder carcinoma.     

Urokinase‐plasminogen‐activator receptor expression in disseminated tumour cells in the bone marrow and peripheral blood of patients with clinically localized prostate cancer

OBJECTIVE

To evaluate the expression of urokinase‐plasminogen‐activator receptor (uPA‐R) in disseminated tumour cells (DTC) in bone marrow (BM) and peripheral blood (PB) of patients with clinically localized prostate cancer before radical prostatectomy (RP), and to assess the associations with pathological variables and prognosis.

PATIENTS AND METHODS

In all, 52 patients (47 with clinically localized cancer and five with benign prostatic hyperplasia, BPH, as controls) were prospectively enrolled. BM and PB samples were drawn before surgery. DTC were enriched using a commercial system, cytokeratin (CK) 8/18 was used to detect DTC, and uPA‐R expression was detected by dual‐immunostaining of the DTC. The final pathology of the RP specimen was compared with the results of immunostaining. Follow‐up was initiated to detect tumour relapse (defined as a prostate‐specific antigen (PSA) level of ≥0.2 ng/mL).

RESULTS

Overall, there was expression of ‘CK + uPA‐R’ in 60% of the BM and in 19% of the PB specimens. Expression of this marker in BM was most significantly increased in those with unfavourable Gleason scores (P = 0.004), followed by high‐risk cancer (P = 0.005). The relative risk for CK + uPA‐R expression in the BM was 3.1 times higher in high‐risk than in low‐risk prostate cancer. No relevant expression rates were detected for PB. In the control group, no patient showed CK or uPA‐R expression in BM or PB. The PSA‐recurrence free survival was significantly lower in patients with CK + uPA‐R‐positive BM cells (P = 0.01).

CONCLUSION

In this pilot study, the preoperative detection rate of CK + uPAR expression in BM of patients with prostate cancer increased with Gleason score and in those with high‐risk disease. All patients with a later PSA relapse had had uPA‐R expression in their DTC from the BM. DTC with uPA‐R expression was an adverse prognostic factor for prostate cancer.     

Acute urinary retention and subsequent catheterization cause lipid peroxidation and oxidative DNA damage in the bladder: preventive effect of edaravone,a free‐radical scavenger

OBJECTIVE

To investigate the effect of a free‐radical scavenger, edaravone, on the changes occurring with acute urinary retention (AUR) and subsequent catheterization in the rat bladder.

MATERIALS AND METHODS

Eight‐week‐old male Sprague Dawley rats were allocated to one of four groups; an AUR group that had urinary retention induced, with subsequent catheterization; two edaravone groups, given edaravone at 1 or 10 mg/kg body weight for 60 min and then the same urinary retention and subsequent catheterization; and a sham‐operated control group given edaravone 10 mg/kg. Urinary retention was induced by the clamping the rat penile urethra with a small clip, making a cystostomy, and then infusing 3 mL (0.6 mL/min) of saline with an infusion pump. The obstruction was sustained for 30 min and then the bladder was allowed to drain with a catheter in place for 60 min as the studies continued. After killing the rats the function of the bladder was assessed, with carbachol and 100 mm KCl, and the levels of malondialdehyde (MDA, a marker of lipid peroxidation), 8‐hydroxydeoxyguanosine (8‐OHdG; a marker of oxidative DNA damage), heat‐shock protein 70 (HSP 70) and its mRNA were measured.

RESULTS

AUR increased the intravesical pressure and decreased blood flow, and subsequent catheterization decreased the intravesical pressure and increased blood flow. Edaravone induced a decrease in blood flow in the bladder during the urinary retention and subsequent catheterization compared to the blood flow in the AUR group. Edaravone resulted in protection of the contractile responses to both carbachol and KCl in a dose‐dependent manner. The MDA concentration, 8‐OHdG content and expressions of HSP‐70 and its mRNA in the AUR group were significantly larger than those of the control group. Edaravone markedly suppressed the accumulations of MDA and 8‐OHdG in the bladder, and reduced the expressions of HSP 70 and its mRNA.

CONCLUSION

These results indicate that edaravone reduces the oxidative stress and prevents the bladder dysfunction caused by AUR and subsequent catheterization.