Browsing by Author "Kaestner, Lisa-Ann"

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    A Retrospective Audit Of Biojet® Prostate Fusion Biopsies Amongst Patients Seen In A High-Volume Private Referral Centre In Cape Town Between January 2017 And April 2020
    (2023) Patel, Bhavinkumar; Kaestner, Lisa-Ann
    Introduction: The field of prostate cancer has seen a dramatic change in its approach to diagnosis, from the advent of PSA in the 1980s to the transrectal ultrasound guided 12 core biopsies with a false negative rate of approximately 30%. Recent advances in this field involve fusing MRI images with real-time ultrasound images to guide the surgeon. The aim of the study was to evaluate the performance of Biojet® prostate fusion biopsy system in a high-volume private referral centre. Methods: Retrospective observational audit of men who presented to a private urology practice in Cape Town for Biojet® prostate fusion biopsy based on clinical suspicion for prostate cancer. Data were collected as per the recommendations of the Standards of Reporting for MRI-targeted Biopsy Studies (START) of the Prostate group and anonymously entered onto a Redcap database. Results: The median age of the patient population was 64 (SD 9.124) years. The median PSA level was 6.5 ng/ml (IQR- 4.7). Most patients (78/135) had a clinical stage of T1c (57%). In the biopsy naïve group, a total of 103 PIRADS lesions were identified. Amongst the PIRADS 3 lesions 15/28 lesions (53%) had a positive cancer diagnosis. Of the PIRADS 4 lesions 37/60 lesions (62%) had a positive cancer diagnosis and in the PIRADS 5 group 13/15 lesions (87%) had a positive cancer diagnosis. 21 of the 42 men (50%) with a previous negative prostate biopsy had a positive cancer diagnosis using the Biojet® prostate fusion biopsy. Conclusion: In this study the Biojet® prostate fusion biopsy performed similar to other international studies however the pickup rate of cancer in those who had a previous negative biopsy was higher than those seen in the other global studies.
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    Comparative Analysis of Kidney Stone Composition in Patients from Ghana and South Africa: Case Study of Kidney Stones from Accra and Cape Town
    (2019) Akpakli, Evans Ametefe; Kaestner, Lisa-Ann; Lazarus, John
    Aim: The primary aim of this study was to describe and compare the kidney stone composition of kidney stone patients receiving treatment at the Korle-Bu Teaching Hospital (KBTH), Accra (Ghana) and Groote Schuur Hospital (GSH), Cape Town (South Africa). Methods: The study was a retrospective folder review of patients treated for kidney stone disease at the Korle-Bu Teaching Hospital in Accra (Ghana) and Groote Schuur Hospital in Cape Town (South Africa). Patients who were treated for kidney stone disease between 1st June 2016 and 31st May 2018 were recruited and their folder numbers were retrieved from theatre log books. A total of hundred and sixty-three (n=163) folders (n=30 KBTH; n=133 GSH) were subsequently retrieved from the records department of the two facilities. Demographic data and kidney stone analysis results were extracted and analyzed using the R statistical software. Results: The age of participants at the KBTH ranged from 24 to 75 years with a median age of 45 years, while the ages of participants at the GSH ranged between 19 to 77 years with a median age of 48 years. Males were the majority stone formers for both hospitals [56.7% KBTH; 59.4% GSH]. However, there was no significant statistical difference in gender (p=0.9447) and age (p=0.2612) between the two groups. Calcium oxalate (86.7%) and uric acid (90.0%) were the commonest components of the kidney stones analyzed from the KBTH. Calcium oxalate (66.2%) and carbonate apatite (40.6%) emerged as the most common components of the stones analyzed from the GSH. Brushite (3.0%), cystine (3.8%) and struvite (19.6%) stones were only found in the stones of participants receiving treatment at the GSH. All kidney stones from the KBTH were mixed; made up of at least two chemical components. Pure kidney stones were only found among the GSH dataset constituting 48.9% of all the stones analyzed. While all KBTH stones were mixed stones, female patients from GSH formed more mixed stones than their male counterparts (M:F = 40.5%:66.67%). Infection kidney stones (struvite and carbonate apatite) were also predominantly found among female stone formers in this study. Conclusion: The findings indicate that the participants from the two facilities are not different in terms of gender and age. However, the composition of stones was found to be different between participants from both hospitals. This suggests that that kidney stone composition may be influenced by patients’ geographical location and/or cultural background. Further studies with prospective or longitudinal data and larger samples are needed to provide more insight into the composition of kidney stones of African patients.
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    Do percutaneous nephrostomies for malignant obstructive uropathy improve renal function six months post intervention?
    (2019) De Wet, Christiaan Ernst; Kaestner, Lisa-Ann
    Background and purpose Malignant conditions of the pelvis and/or abdomen can cause ureteric obstruction and associated impaired renal function, which can be managed by performing percutaneous nephrostomy (PCN) tube insertion. Nephrostomy tubes are associated with prolonged hospital stay which affects quality of life. The main objective of this study was to assess the changes in estimated glomerular filtration rate (eGFR) over the first six months following percutaneous nephrostomy for malignant ureteric obstruction. We also explored the role of UTIs in the changes of eGFR following PCN. Materials and Methods We performed a retrospective folder review of patients who had PCN procedures at Groote Schuur Hospital for malignant obstructive uropathy from January 2015 to 31 December 2017. For each included patient, eGFR was recorded at baseline pre-PCN, and at its best and worst value in the first six months after PCN. The timing of baseline, best and worst values were also recorded. Other data collected included demographic data, type of malignancy, laterality of nephrostomy and presence of confirmed UTI at least one week post PCN. Results/main findings A total of 90 patients fulfilled our inclusion criteria. The most common cancers in men were bladder 59% (n=32), prostate 20% (n=11), lymphoma 7% (n=4), and colorectal 4% (n=2). The most common cancers in women were cervix 64% (n=23), bladder 19% (n=7), lymphoma 6% (n=2), colorectal 6% (n=2) and endometrial 6% (n=2). Men were of higher age, median (IQR), 60 (56, 67) years, compared to women, 48 (40, 67). 64% of patients (n=58) had bilateral PCN procedures (as opposed to a unilateral procedure). 52% (n=47) of patients developed at least one episode of UTI post PCN during the six-month observation period. Median (IQR) timepoint of pre-PCN eGFR measurement was 1.0 (2.0, 0) day pre PCN. The best post-PCN eGFR measurement was 13.0 (6.0, 26.0) days post PCN. The worst post-PCN measurement was 33.5 (14.0, 92.5) days post PCN. Pre-PCN eGFR, median (IQR), was 9 (5, 26). Post-PCN eGFR improved to 48 (30, 75) before deteriorating to 23 (9, 44) within the six-month follow-up window. Compared to patients who do not develop UTI post-PCN, those who develop one or more post-PCN UTI(s) have a 6.15 (95% CI: 0.87, 11.43) unit lower eGFR at their worst eGFR measurement. There are also markedly fewer deteriorations in chronic kidney disease (CKD) stages between best and worst post-PCN interval in those without UTI (42%, 18/43), compared to those with at least one post-PCN UTI (72%, 34/47). Conclusions Our study confirmed a similar renal function trend post-PCN for malignant ureteric obstruction across different demographics. It is clear that although most patients’ renal function initially improve post-PCN, the general trend for the majority of patients is to deteriorate towards pre-PCN eGFR and CKD stage values. Our data suggest that urinary tract infections play an important role in poor renal function response within six months post-PCN. Future studies should explore whether the development of UTI following PCN is an independent and modifiable risk factor for poor renal outcome.
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    Investigating racial differences in clinical and pathological features of prostate cancer in South African men
    (2016) Dewar, Malcolm James; Kaestner, Lisa-Ann; Lazarus, John
    The aim of this project is to study the clinical and pathological features of prostate cancer in men from different racial groups in the Western Cape in an attempt to define the characteristics of the disease locally. Specifically we wanted to compare black with coloured and white patients.
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    Is ethnicity a risk for high grade prostate cancer?
    (2010) Kaestner, Lisa-Ann
    To assess the association between ethnicity and grade of prostatic adenocarcinoma, prostatespecific antigen (PSA) and age, and to determine whether Africans of African descent (AAD) have higher grade cancers than other ethnic groups.
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    Lessons from a pilot study of screening for upper tract urothelial cell carcinoma in Lynch Syndrome
    (2021) Pluke, Kent David; Kaestner, Lisa-Ann
    Background: Lynch syndrome is a hereditary disorder, with a very high risk of the developing colorectal cancer (CRC) and a predilection to develop other cancers, including upper tract urothelial carcinoma (UTUC) that has an estimated lifetime risk of 0.2-25%, above that of the general population. Our aim was to assess the prevalence of UTUC in a Lynch syndrome cohort undergoing screening for CRC, to determine the need for a UTUC screening program. Methodology: Lynch syndrome patients were screened with urine dipstix for microscopic haematuria. Patients with confirmed microhaematuria were offered urine cytology, microscopy and culture, ultrasound (US) of their upper tracts and flexible cystoscopy. Results: Of the 89 patients screened, 86 had an MLH1 mutation and 2 had an MSH2 mutation. Eleven of the 12 patients who had microscopic haematuria were female. 10 patients had urinary tract infections. One patient had follicular cystitis and another had a simple renal cyst. No patients had hydronephrosis on ultrasound. All urine cytology specimens were negative for malignancy. Conclusion: No cases of UTUC were detected in our cohort during this study. A more rational screening protocol in this group may be to screen patients for UTUC with known MSH2 mutations at an earlier age (over 35).
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    Mitigation of intrarenal pressure in retrograde intrarenal surgery with a novel isoprenaline eluting guidewire
    (2025) John, Jeff; Kaestner, Lisa-Ann; Lazarus, John; Fieggen, Graham
    Urolithiasis ranks as the third most prevalent condition in urology, with statistical evidence indicating a lifetime risk of 13% in males and 7% in females, alongside a recurrence rate of 50% within a decade. The surgical care of urolithiasis is intricate, with various competing therapeutic techniques available, including retrograde intrarenal surgery (RIRS). Over the years, leading urological associations have progressively broadened the criteria for RIRS in the surgical treatment of urolithiasis. While it offers enhanced stone-free rates relative to shockwave lithotripsy and reduced patient morbidity compared to percutaneous nephrolithotomy, it is not devoid of problems, many of which are associated with intrarenal pressure (IRP). To alleviate the challenges associated with increased IRP, surgeons may utilize diverse approaches to regulate IRP. Pharmacologic therapies in the perioperative period to mitigate IRP have been documented, although none of these strategies have been integrated into clinical practice. This thesis aims to report on the design, safety, and efficacy of an innovative isoprenaline-eluting guidewire (IsoWire), a platform guidewire intended for the administration of topical isoprenaline, a beta-receptor agonist, to the genitourinary system. This is the first study to report the delivery of isoprenaline using a drug-eluting guidewire. This dissertation comprises six chapters. The initial five chapters each have an overview, abstract, introduction, methodology, results, discussion, and conclusion sections. Chapter 1 is a narrative literature review addressing the problems associated with high IRP and outlines techniques to mitigate elevated IRP in RIRS to promote safer endourological practices. To prepare for our investigation on the porcine model, we required a simulation model to precisely outline the procedural procedures. Commercially available models are expensive and not readily accessible. Chapter 2 delineates the design and fabrication of the Frere Intrarenal Surgery Trainer (FiST) bench-top model. This chapter further elucidates its validation through the involvement of individuals with prior competence in the RIRS technique. This high-fidelity, cost-effective, portable, durable, and reusable training model is, to our knowledge, the inaugural published 3D model that integrates all components of RIRS, allowing us to meticulously optimise the procedural stages for our research. The porcine model has frequently been utilized by researchers and urological surgeons for medical advancements. Despite the multiple advantages of this model, the specific anatomical knowledge that qualifies it as the optimal model in urology remains inadequately defined. In Chapter 3, we present the first reported study that precisely delineates pertinent endoscopic and CT-based urological anatomy of female Landrace pigs. The insights acquired from this research were essential for proceeding with the two studies described in Chapters 4 and 5. Furthermore, this unprecedented research will help other researchers use the porcine model to conduct research in endourology with confidence. Chapter 4 delineates the design of the IsoWire and examines the results of the preliminary in vitro release studies. Furthermore, we evaluated IsoWires of three distinct strengths, specifically wires that release 5 μg, 7.5 μg, and 10 μg in the first minute minute, respectively. Our investigation demonstrated that the IsoWire, which released 7.5 μg of isoprenaline within the initial minute, is safe, showing no alterations in mean arterial pressure (MAP), heart rate (HR), or other irregular electrocardiographic (ECG) abnormalities. Moreover, the in vitro release assays demonstrated that the IsoWire released all isoprenaline exponentially within the initial 4 minutes. Chapter 5 delineates the impact of the IsoWire, which dispenses 7.5 μg of isoprenaline within the initial minute, on IRP, the duration of this effect, and its safety in a porcine model. Chapter 6 presents a conclusion and reflection on this thesis, emphasising its original contributions to the field of urology and addressing prospective avenues for future research.