ChatGPT on guidelines: Providing contextual knowledge to GPT allows it to provide advice on appropriate colonoscopy intervals.

BACKGROUND AND AIM: Colonoscopy is commonly used in screening and surveillance for colorectal cancer. Multiple different guidelines provide recommendations on the interval between colonoscopies. This can be challenging for non-specialist healthcare providers to navigate. Large language models like ChatGPT are a potential tool for parsing patient histories and providing advice. However, the standard GPT model is not designed for medical use and can hallucinate. One way to overcome these challenges is to provide contextual information with medical guidelines to help the model respond accurately to queries. Our study compares the standard GPT4 against a contextualized model provided with relevant screening guidelines. We evaluated whether the models could provide correct advice for screening and surveillance intervals for colonoscopy. METHODS: Relevant guidelines pertaining to colorectal cancer screening and surveillance were formulated into a knowledge base for GPT. We tested 62 example case scenarios (three times each) on standard GPT4 and on a contextualized model with the knowledge base. RESULTS: The contextualized GPT4 model outperformed the standard GPT4 in all domains. No high-risk features were missed, and only two cases had hallucination of additional high-risk features. A correct interval to colonoscopy was provided in the majority of cases. Guidelines were appropriately cited in almost all cases. CONCLUSIONS: A contextualized GPT4 model could identify high-risk features and quote appropriate guidelines without significant hallucination. It gave a correct interval to the next colonoscopy in the majority of cases. This provides proof of concept that ChatGPT with appropriate refinement can serve as an accurate physician assistant.

Cost-effectiveness of alternative first- and second-line treatments for benign prostatic hyperplasia in Singapore.

BACKGROUND: Minimally invasive surgical therapies, such as water vapor thermal therapy (WVTT) and prostatic urethral lift (PUL), are typically second-line options for patients in whom medical management (MM) failed but who are unwilling or unsuitable to undergo invasive transurethral resection of the prostate (TURP). However, the incremental cost-effectiveness of WVTT or PUL as first- or second-line therapy is unknown. We evaluated the incremental cost-effectiveness of alternative first- and second-line treatments for patients with moderate-to-severe benign prostatic hyperplasia (BPH) in Singapore to help policymakers make subsidy decisions based on value for money. METHODS: We considered six stepped-up treatment strategies, beginning with MM, WVTT, PUL or TURP. In each strategy, patients requiring retreatment advance to a more invasive treatment until TURP, which may be undergone twice. A Markov cohort model was used to simulate transitions between BPH severity states and retreatment, accruing costs and quality-adjusted life-years (QALYs) over a lifetime horizon. RESULTS: In moderate patients, strategies beginning with MM had similar cost and effectiveness, and first-line WVTT was incrementally cost-effective to first-line MM (33,307 SGD/QALY). First-line TURP was not incrementally cost-effective to first-line WVTT (159,361 SGD/QALY). For severe patients, WVTT was incrementally cost-effective to MM as a first-line treatment (30,133 SGD/QALY) and to TURP as a second-line treatment following MM (6877 SGD/QALY). TURP was incrementally cost-effective to WVTT as a first-line treatment (48,209 SGD/QALY) in severe patients only. All pathways involving PUL were dominated (higher costs and lower QALYs). CONCLUSION: Based on the common willingness-to-pay threshold of SGD 50,000/QALY, this study demonstrates the cost-effectiveness of WVTT over MM as first-line treatment for patients with moderate or severe BPH, suggesting it represents good value for money and should be considered for subsidy. PUL is not cost-effective as a first- nor second-line treatment. For patients with severe BPH, TURP as first-line is also cost-effective.

Benign prostatic hyperplasia (BPH) is a non-cancerous enlargement of the prostate, common among older men. Its symptoms include difficulties with starting and completing urination, incontinence, frequent and urgent need to urinate. Minimally invasive procedures, such as water vapor thermal therapy (WVTT) and prostatic urethral lift (PUL), are typically offered as second-line options to patients for whom medication has failed but who are unwilling or unsuitable to undergo invasive surgery (transurethral resection of the prostate, TURP). However, whether offering these procedures as first-line options represents good value for money (i.e. cost-effectiveness) is an open question. To address this question and inform subsidy decisions in Singapore, we investigated six stepped-up treatment strategies which differ in first- and second-line treatments. For each strategy, we simulated healthcare costs and quality of life for a cohort of moderate and severe BPH patients over their lifetime, considering the possibility of treatment-related adverse effects and multiple rounds of retreatment. The incremental cost of a unit improvement in quality of life for a strategy relative to the next most expensive one was compared against a willingness-to-pay threshold to determine cost-effectiveness. We found that WVTT was cost-effective relative to medication as a first-line treatment for patients with moderate or severe BPH, suggesting it represents good value for money and should be considered for subsidy. PUL was not cost-effective as first- nor second-line treatment. TURP is cost-effective as first-line for severe BPH patients only.

Indocyanine green - guided laparoscopic renal pedicle lymphatic disconnection: A novel, targeted treatment for chyluria.

INTRODUCTION AND OBJECTIVES: Chyluria, or the passage of chyle into the urine from anomalous lymphatic connections, results in a characteristic milky urine. In severe cases, it can cause signifi cant morbidity from nutritional losses and immune suppression. Although predominantly associated with Wuchereria bancrofti infections, non-parasitic cases have also been described. Traditionally, surgical treatment has involved renal lymphatic disconnection using open or minimally invasive methods, occasionally aided by pre-operative imaging techniques like lymphangiography, or by identifi cation of structures with laparoscopic magnifi cation.

Gastric banding clip in the urinary bladder.

BACKGROUND AND AIM: A wide variety of foreign bodies have been found in the urinary bladder, most often due to self-introduction and autoerotism, or iatrogenically introduced during surgery in the anatomic region. We report the first case of a gastric banding clip found in the urinary bladder. CASE PRESENTATION: We describe the case of a 33-year-old Chinese female who had previously undergone gastric banding and subsequent removal of the band. She presented with lower urinary tract symptoms which followed a diurnal pattern, and investigations revealed a portion of a gastric banding clip in the urinary bladder. There was no sign of perforation or erosion of the bladder. The clip was surgically removed and the patient recovered without complications. DISCUSSION AND CONCLUSION: This is the first reported case of an intraperitoneal gastric banding clip migrating extraperitoneally into the urinary bladder. The use of the urinary bladder to expel foreign bodies has been documented in other vertebrates, and the mechanism by which this occurs without perforation or erosion of the urinary bladder warrants further investigation.

Novel use of a balloon dilatation catheter to enable mechanical lithotripsy of difficult common bile duct stones after initial failed attempt: A case report.

INTRODUCTION: Difficult and large common bile duct stones can be crushed and removed using a mechanical lithotripter. Very often the lack of working space within the common bile duct causing the failure of mechanical lithotripsy would inevitably mean repeat or further invasive procedures. PRESENTATION OF CASE: A patient with large and multiple common bile duct stones underwent ERCP, and initial deployment of a mechanical lithotripter failed due to the lack of working space within the common bile duct. A through-the-scope (TTS) dilator was utilized to increase the working space before successful deployment of the mechanical lithotripter, and subsequent clearance of all stones within the same setting. DISCUSSION: We herein describe a novel and ingenious technique of utilizing a through-the-scope (TTS) dilator in helping to expand the space within the common bile duct to allow for full deployment of a mechanical lithotripter and successful clearance of common bile duct stones. This method can be easily applied by advanced endoscopists and is expected to lead to increased success rates of difficult common bile duct stones clearance in a single setting. CONCLUSION: Use of TTS dilators to increase working space within the common bile duct can be useful in increasing the success rates of mechanical lithotripsy in the setting of large and multiple common bile duct stones.