Tet Yap

Tet Yap
Guy's and St Thomas' NHS Foundation Trust · Department of Urology

About

162
Publications
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988
Citations
Citations since 2017
82 Research Items
677 Citations
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2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Introduction
Skills and Expertise

Publications

Publications (162)
Article
Objectives Guy's and St Thomas’ NHS Foundation Trust started a specialist Klinefelter's Syndrome clinic in 2019 which has a multidisciplinary team including a Urologist, Endocrinologist, Assisted Reproduction Specialist, Urology specialist, pharmacist and A Psychosexual Specialist Consultant. We have developed HS protocol for NOA with KS. We are co...
Article
Objectives Guy's and St Thomas’ NHS Foundation Trust started a specialist Klinefelter's Syndrome clinic in 2019 which has a multidisciplinary team including a Urologist, Endocrinologist, Assisted Reproduction Specialist, Urology specialist, pharmacist and A Psychosexual Specialist Consultant. We have developed HS protocol for NOA with KS. We are co...
Article
Across health care, clinicians are increasingly using patient-reported outcome measures (PROMs) to give a voice to patients and to help standardize the assessment of patients for comparison purposes. With this increasing use, the limitations of these PROMs should not be underestimated within the diverse population that we treat.
Article
Objective To study the differences in sexual dysfunction and time to pregnancy (TTP) between infertile couples pursuing timed intercourse (TI – around the time of ovulation) and regular intercourse (RI – at least twice a week). Methods In this prospective cohort study, we recruited all infertile couples presenting to the regional infertility clini...
Article
Introduction Intracavernosal injections (ICI) are the second line treatment of erectile dysfunction (ED). To reduce the risk of complications, primarily priapism, the first administration has traditionally required face-to-face appointments. With a move to remote working, the safety and feasibility of an instructional video for the first self-admin...
Article
Study question What is the incidence of sperm DNA damage in men attending tertiary (urological) healthcare with long histories of infertility? Summary answer The majority of these men (95%), all with normal semen analyses had high levels of sperm DNA damage. What is known already Conventional semen analysis assesses sperm concentration, motility,...
Article
Study question Investigate the differences in sexual dysfunction and time to pregnancy between infertile couples pursuing timed intercourse and Regular Intercourse (RI at least twice a week). Summary answer TI significantly increased the risk of SD compared to RI for both males and females after adjusting all other contributing factors. What is k...
Article
Study question Are couples presenting to infertility clinics actually infertile, or is there an undiagnosed underlying sexual dysfunction whose treatment can lead to natural conception avoiding the need for assisted reproductive techniques? Summary answer All couples presenting with infertility should be asked about sexual function. If sexual dysf...
Article
Full-text available
Aims KS is a congenital condition with 47, XXY chromosome karyotype. Due to a lack of understanding of the condition amongst healthcare providers, KS is grossly underdiagnosed, with most patients never receiving a diagnosis. Within this population, gender dysphoria is suggested to be of higher incidence than in the general population. To establish...
Article
Full-text available
Background: The beneficial effects of hormonal therapy in stimulating spermatogenesis in patients with non-obstructive azoospermia (NOA) and either normal gonadotrophins or hypergonadotropic hypogonadism prior to surgical sperm retrieval (SSR) is controversial. Although the European Association of Urology guidelines state that hormone stimulation...
Article
Introduction Klinefelter's syndrome is the most common chromosomal abnormality seen in men, affecting 1 in 650 men. It is a group of chromosomal disorders with at least one extra X chromosome (47, XXY) occurring due to non-disjunction at the time of gametogenesis. Most adult men are diagnosed at the time of fertility investigations. However, the sy...
Article
Introduction and Objective Klinefelter Syndrome (KS) is the commonest hypo-androgenic chromosomal anomaly affecting fertility (1:600 men). KS frequently goes undiagnosed until middle age during fertility investigations. However, beyond fertility issues there is little known of the psychological effect of KS on these newly diagnosed men. This study...
Article
Introductions Most children are diagnosed with Klinefelter's as part of investigating learning and behavioural difficulties or during prenatal screening. Klinefelter's is the most common chromosomal abnormality affecting men (1 in 650) and is associated with a large spectrum of clinical manifestations including learning, behavioural and development...
Article
Background & Objectives Onco-microsurgical testicular sperm extraction (Onco-microTESE) allows the microsurgical extraction of testicular sperm from the unaffected regions of the tumour-bearing testis at the time of radical orchidectomy. We report the case of a 36-year-old hypogonadotropic male with a testicular tumour and non-obstructive azoosperm...
Article
An imbalance in the genitourinary microbiome is emerging as a contributing factor to male infertility. The purpose of this study was to determine whether there is an association between genitourinary microorganisms and seminal oxidative stress, sperm DNA fragmentation and semen parameters. It included 770 men attending for diagnostic testing for su...
Article
Focus on quality of life after prostate cancer is vital to improve patient care. Improved assessment and proactive management of post-treatment functional outcomes is essential. Many aspects of the patients’ aftercare need to be improved in order to set up a clear path following prostatectomy. These improvements will enable a timely and efficient e...
Article
Context: Focal therapy has emerged as a promising option to treat well-selected men with localised prostate cancer while preserving healthy prostate tissue and key structures, such as the urethral sphincter and neurovascular bundles. However, how this tissue preservation may translate into improved outcomes, particularly into improved sexual outco...
Article
Full-text available
Introduction: Our study analysed previous studies employing Positron Emission Tomography with co-registered Computer Tomography (PET/CT) in andrological patient evaluation and assessed the differences in 2-[18 F]F-fluoro-2'-deoxyglucose (FDG) uptake between 3 groups: healthy testes, benign and malignant testicular pathology. Methods: MEDLINE and...
Article
Full-text available
Purpose Improved medical care throughout childhood and adolescence has enabled patients with complex urological abnormalities to live longer into adulthood. These patients are now at risk of developing common, age-related, urological conditions. This review aims to review existing data and make recommendations in areas where expert opinion is curre...
Article
Full-text available
Objectives: To determine the safety of urological admissions and procedures during the height of the COVID-19 pandemic using "hot" and "cold" sites. The secondary objective is to determine risk factors of contracting COVID-19 within our cohort. Patients and methods: A retrospective cohort study of all consecutive patients admitted from March 1 t...
Article
Seminal oxidative stress (OS) is a major contributing factor to male infertility. Semen analysis cannot identify reactive oxygen species (ROS), which can be measured using a chemiluminescence assay. Measurement of redox potential provides a more comprehensive assessment of OS, although the test has yet to be fully validated. This study aimed to val...
Article
Full-text available
Introduction Focal therapy has emerged as a promising treatment option for men with localised prostate cancer. However, most of the evaluation of postoperative function has taken place at a relatively high, non-granular level. Most of the data we use to provide informed consent for our patients is obtained from retrospective series, or derived from...
Preprint
Full-text available
Importance: Contracting COVID-19 peri-operatively has been associated with a mortality rate as high as 23%. Using hot and cold sites has led to a low rate of post-operative diagnosis of COVID-19 infection and allowed safe continuation of important emergency and cancer operations in our centre. Objective: The primary objective was to determine the s...
Article
Full-text available
Background Male factor is attributable in up to 50% of cases of infertility. In‐vitro studies demonstrate that bacteria can negatively impact sperm function. The use of next‐generation sequencing (NGS) techniques have provided a better understanding of the human microbiome, and dysbiosis has been reported to impact health. Evidence regarding the im...
Article
Full-text available
Study question: Do the Comet parameters of the proportions of sperm with low or high DNA damage improve the power of the test in the diagnosis of male infertility and/or prediction of IVF and ICSI live birth rates? Summary answer: The mean Comet score and the scores for proportions of sperm with high or low DNA damage were useful in diagnosing m...
Article
Background: The oncological outcomes in men with clinically significant prostate cancer following focal cryotherapy are promising, although functional outcomes are under-reported. Objective: To determine the impact of focal cryotherapy on urinary and sexual function, specifically assessing return to baseline function. Design, setting, and parti...
Article
Background: Focal cryotherapy can be used to treat patients with clinically significant nonmetastatic prostate cancer to reduce side effects. Objective: Early-medium-term cancer control and functional outcomes. Design, setting, and participants: A prospective registry-based case series of 122 consecutive patients undergoing focal cryotherapy b...
Article
Male infertility is a major health burden worldwide. In the United Kingdom, the diagnostic and treatment pathway for male factor fertility is fragmented with wide variance in management and funding protocols. There is now a focus on potential overtreatment of couples with IVF and failure to treat male factors before considering assisted reproductiv...
Article
A systematic review and meta-analysis was performed to determine the relationship between testosterone therapy and risk of recurrence in testosterone-deficient survivors of curatively treated high-risk prostate cancer. Primary outcome was the risk of biochemical recurrence (BCR) in 109 high-risk patients in 13 included studies (1997-2017). Biochemi...
Article
Objectives To determine the impact of testicular cancer and its treatments on fertility and to review the current management options for the infertile, testicular cancer patient, both before diagnosis and after treatment, with the aim to provide practical recommendations to update contemporary guidelines and standardise clinical practice. Patients...
Article
The live birth rates (LBRs) in men with non-obstructive azoospermia (NOA) undergoing microdissection TESE (mTESE) are under reported, with surgical sperm retrieval rate often used as the primary outcome measure. We analysed longitudinal and cumulative delivery rates following mTESE– intracytoplasmic sperm injection (ICSI) in NOA. Sperm was retrieve...
Article
Objectives To determine the frequency of spermatogenesis in patients with testicular cancer and to assess for any predictors of spermatogenesis. Patients and Methods We retrospectively reviewed 103 testicular germ cell tumours (TGCTs) in men who underwent radical orchidectomy conducted at Guy's Hospital, London, between 2011 and 2015. Primary outc...
Article
Background Organ sparing surgery (OSS) in the treatment of penile squamous cell cancer (SCCp) is well established. A 5 mm margin has previously been considered oncologically safe. Objective To evaluate the significance of close surgical margins in OSS and clinico‐pathological factors that may influence local recurrence. Patients and Methods At ou...
Article
Full-text available
Objectives: To systematically review erectile function (EF) outcomes following primary whole gland (WG) and focal ablative therapies for localized prostate cancer to ascertain whether the treatment modality or intended treatment volume affects the time taken to recover baseline EF. Method and materials: A systematic review was performed accordin...
Article
Peyronie’s disease (PD) is a debilitating chronic condition associated with penile curvature, erectile dysfunction, pain, and emotional distress (1). The condition was first described in 1743 by Francois Gigot de la Peyronie, King Louis XV of France’s physician (2). PD is a progressive condition characterised by fibrotic plaques within the tunica a...
Chapter
Nocturnal penile tumescence (NPT) is spontaneous penile tumescence occurring during sleep, and typically associated with rapid eye movement (REM) sleep. In contrast to the physiological processes underlying erection at the peripheral level, the physiological process of NPT and its association with REM sleep is relatively unknown. NPT has been used...
Article
Context The human papillomaviruses (HPVs) are a major global health burden, playing a part in diseases ranging from genital warts to malignancies such as penile cancer in men and cervical cancer in women. Objective To explore the molecular biology and epidemiology of HPV infection; the diseases linked to it; and current prevention strategies, incl...
Article
Introduction Recovery of baseline erectile function (EF) after robotic radical prostatectomy in men with high-risk prostate cancer is under-reported. Published studies have selectively reported on low-risk disease using non-validated and poorly defined thresholds for EF recovery. Aim To assess return to baseline EF in men after robotic radical pro...