Biomedical subjects
Publications and source records attributed to Nathan Lawrentschuk.
The key diagnosis and treating of vesicovaginal fistulae is accurate imaging. We illustrate the latest use of enhanced computed tomography for such cases.
INTRODUCTION: The growth of human tumours under the renal capsule in animal models has been performed in the past. However, the use of modern surgical equipment has not always been translated into the laboratory. We report on a novel method for human renal tumour transplants using an automated biopsy gun to obtain tumour tissue and an epidural needle with introducer to easily deploy the grafts under the renal capsule. METHODS: Nude mice had human xenografted tumours grown subcutaneously after implantation of cells from culture. Tumours were then biopsied using a 16-gauge automated biopsy gun. Digital calipers were used to measure a 2-mm segment of the biopsy core that was cut and placed inside a hollow needle (epidural needle). The needle was placed under the renal capsule and the trocar introduced to deploy the graft beneath the capsule with minimal trauma. Further groups had tumour harvested similarly by automated biopsy gun but had the implants placed subcutaneously for comparison. RESULTS: Tumour grafts were established in 90% of grafted kidneys in this renal subcapsular model (229.68 +/- 118.32 mm(3); mean +/- 95% CI) which compared favourably to the subcutaneous model (163.81 +/- 43.3 mm(3)). Grafts were confirmed by direct observation and histology. CONCLUSION: Modern surgical equipment may be utilised to allow tumour transplantation to be precise, with an identifiable and reproducible tumour volume deployed. Surgical researchers and laboratory-based scientists need to embrace new techniques and utilise them to improve models. This model may be adapted to many situations in oncologic research involving xenografting.
Primary sclerosing lipogranuloma is an unusual benign condition of the genitalia typically presenting as a painless mass affecting the penis and scrotum. Its importance lies in differentiating it from malignancy to avoid extensive surgery. It is normally treated with total or partial excision. This is the first reported case where oral corticosteroids have been used to treat this condition whereby a six-week course resulted in the mass disappearing. In conclusion, if sclerosing lipogranuloma is suspected biopsy should be undertaken to exclude sarcoma. We believe surgery should be reserved for recurrent or refractory cases when steroids have failed as first-line treatment.
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PURPOSE: To demonstrate the construction of a simple training model from reconfigured chicken skin to simulate open and laparoscopic reconstructive pyeloplasty. MATERIALS AND METHODS: Reconfiguring and suturing chicken skin dissected off its muscle creates a model of the ureteropelvic junction. Dismembered pyeloplasty techniques may be practiced with open or laparoscopic equipment. Students with prior training in suturing and knot-tying only used the open pyeloplasty model on three occasions. Urology trainees experienced in surgery but not laparoscopic pyeloplasty used the model laparoscopically. RESULTS: Students demonstrated a significant improvement (P < 0.05) between their first (17.00 +/- 4.44 minutes; mean +/- 95% CI) and third (11.33 +/- 2.40 minutes) attempts using the open model. Urology trainees improved their mean times from the first (18.0 minutes) to third (11.8 minutes) attempts using the laparoscopic model. CONCLUSIONS: This cheap and readily available model is reproducible and applicable to training in both open and laparoscopic pyeloplasty.
Fluorine-18 fluorothymidine (F-18 FLT) is a radioisotope based on the nucleic acid thymidine and has emerged as an important tracer that mirrors cellular proliferation in positron emission tomography (PET) studies. Early studies in human tumors have been promising. However, imaging of renal tumors using F-18 FLT PET studies has not previously been described. In this report, a difficult case of renal transitional cell carcinoma in a longstanding cyst was clearly delineated using F-18 FLT. Importantly, the study was able to guide clinicians toward appropriate surgical management. The use of such tracers may herald a new era in renal tumor imaging.
OBJECTIVE: To investigate if women with recurrent urinary tract infection (UTI) warrant cystoscopy to exclude an abnormality of the lower urinary tract. This is particularly relevant given that non-invasive imaging has often been performed to exclude abnormality. Our further aims were to correlate imaging and risk factors with cystoscopic findings to determine their predictive value in finding pathology. PATIENTS AND METHODS: A database of women undergoing cystoscopy with recurrent UTI has been maintained at our institution for 10 years. We retrospectively examined this and patient records for patient demographics, and investigative and operative data. RESULTS: A total of 118 patients (mean 55 years) having recurrent UTI (mean 4.7 infections/year) were available. There were nine patients (8%) with significant abnormalities at cystoscopy: urethral stricture (six), bladder calculus (one), bladder diverticulum (one) and colovesical fistula (one). The negative predictive value (NPV) of imaging was 99% and significant (P < 0.01). Women with no risk factors for UTI had a NPV of 93% for normal cystoscopy (P > 0.05). The positive predictive value was low for imaging and risk factors in predicting cystoscopy findings. CONCLUSIONS: In our study, 8% of women had significant abnormalities detected during cystoscopy with most over 50 years. Women without risk factors for recurrent UTI and with normal imaging could have a cystoscopy omitted. Younger women are less likely to have pathology and this must be factored into decisions to perform cystoscopy.
Metastases to the penis are a rare event with most arising from pelvic organs, but occasionally the kidneys. Furthermore, very few cases exist where primary rectal carcinoma metastasising to the penis has been reported. We report on such a case and discuss the general management of penile metastases.
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OBJECTIVES: To ascertain the frequency of in-hospital deaths after urological surgery in a compulsory reporting setting, and to identify the contributing and potentially reversible factors involved in patients who had had transurethral resection of the prostate (TURP). METHODS: We reviewed all hospital deaths reported to the State Coroner from Coronial Services Victoria (CSV), Australia, in 2000-2002 to identify those instances associated with urological surgery. These cases were then analysed using methods developed by CSV. Resources available included medical records, police reports, government data on operative procedures and autopsy results. RESULTS: There were 20 in-hospital deaths after urological surgery identified for the 3-year period; most related to pre-existing comorbidities, predominantly ischaemic heart disease. Two episodes of hospital-acquired infection, two instances of technical complication of surgery contributing to death, and one pulmonary embolus were identified. Numerically the largest group of deaths after surgery was patients having TURP, and these deaths represented 0.05% (nine of 17 044) of all TURPs in this period. Most in this group (eight) had an acute myocardial infarction. CONCLUSION: Death after urological surgery appears to be uncommon; assessing patients for coronary artery disease before urological surgery, particularly TURP, closer cardiovascular monitoring after surgery, and rapid transfer to a coronary care unit if required, may further reduce mortality.
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OBJECTIVE: To evaluate the accuracy of fine-needle aspiration (FNA) cytology of palpable inguinal lymphadenopathy before definitive management of the primary tumour, in predicting inguinal lymph node (LN) metastasis in men with primary squamous cell carcinoma (SCC) of the penis. PATIENTS AND METHODS: Sixteen men with primary SCC of the penis and palpable inguinal lymphadenopathy (unilateral or bilateral) were treated by primary resection and bilateral inguinal LN dissection. FNA cytology was analysed for 25 palpable inguinal LNs at the time of penile biopsy. The sensitivity, specificity and accuracy of FNA cytology was compared with the histological findings from surgical LN clearance. RESULTS: The 25 FNAs were without complication and without evidence of implantation of metastasis in the needle tracts; 14 FNA samples were positive for metastasis, 10 were negative, and one was inconclusive. From the histological assessment of the surgical inguinal LN specimens, FNA cytology had a sensitivity of 93%, and specificity of 91% in predicting metastatic disease. CONCLUSION: FNA cytology of palpable inguinal lymphadenopathy before surgery for the primary tumour has a high sensitivity and specificity for metastatic penile cancer. This procedure permits early inguinal lymphadenectomy where appropriate without need for prolonged initial antibiotic treatment.
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UNLABELLED: PET offers a noninvasive means to assess neoplasms, in view of its sensitivity and accuracy in staging tumors and potentially in monitoring treatment response. The aim of this study was to evaluate newly diagnosed primary brain tumors for the presence of hypoxia, as indicated by the uptake of 18F-fluoromisonidazole (18F-FMISO) and to examine the relationship of hypoxia to the uptake of 18F-FDG and molecular markers of hypoxia. METHODS: Seventeen patients with suspected primary glioma were enrolled prospectively in this study. Sixteen patients had histology, with 2 having metastatic disease. All patients had PET studies with 18F-FMISO and 18F-FDG and MRI studies. Immunohistochemistry was undertaken with tumor markers of angiogenesis and hypoxia. Patients were monitored for disease progression and statistical analysis of data was performed. RESULTS: Of the 14 patients with histology, 8 died with a median time of 16 mo (range, 2-30 mo) until death. Of those who died, 7 had positive and 1 had negative 18F-FMISO uptake. 18F-FMISO uptake was observed in all high-grade gliomas but not in low-grade gliomas. A significant relationship was found between 18F-FDG or 18F-FMISO uptake and expression of VEGF-R1 and Ki67 expression. Other immunohistochemical markers demonstrated a trend toward increased uptake but none was significant. CONCLUSION: 18F-FMISO PET provides a noninvasive assessment of hypoxia in glioma and was prognostic for treatment outcomes in the majority of patients. 18F-FMISO PET may have a role not only in directing patients toward targeted hypoxic therapies but also in monitoring response to such therapies.
BACKGROUND PURPOSE: Spleen-preserving distal pancreatectomy, although rarely performed, has become an option for treatment of distal pancreatic neoplasms. However, the spleen, once mobilised, is often free to tort. A reliable method of fixing the spleen would be a useful adjunct to this procedure. METHODS: We describe the use of a new technique to fix the spleen using a peritoneal "pillowcase" to envelop the spleen, thus preventing its torsion. RESULTS: This patient has done well, with no problems encountered intraoperatively or postoperatively, using this new technique of spleen fixation. CONCLUSIONS: The use of a peritoneal "pillowcase" to envelope the spleen following distal pancreatectomy has proven a useful adjunct to this somewhat difficult surgical procedure. It may be applied in other cases where spleen fixation is necessary.
A simple technique using a fenestrated urethral catheter to assist in drainage of pericatheter urethral exudates from the anastomosis of the urethra to the bladder neck in radical prostatectomy is described. It is applicable to open and laparoscopic techniques of radical prostatectomy.