Bogdan Geavlete

Chapter 1 – History

The first historical report regarding the percutaneous approach of the kidney was by Thomas Hillier, in London. He approached and drained percutaneously the hydronephrotic kidney of a 4-year-old boy. Over a period of 5 years, until the patient died, multiple nephrostomies were placed in the attempt to create a permanent fistulous tract. After this first attempt, the percutaneous approach went into obscurity for more than 85 years until the mid-1950s, when Goodwin et al. reported a new series of percutaneous nephrostomies in 16 patients (Goodwin, W.E., Casey, W.C., Woolf, W., 1955. Percutaneous trocar (needle) nephrostomy in hydronephrosis. J. Am. Med. Assoc. 157 (11), 891–894). Surprisingly, the method was abandoned again until the 1970s, when it was resumed. After that it became extremely popular, becoming the first option of treatment in the detriment of open nephrostomy. Moreover, the first intrarenal therapeutic maneuvers were attempted through the percutaneous tract. Nephroscopy and the percutaneous extraction of some lithiasic fragments was first reported by Rupel and Brown (Rupel, E., Brown, R., 1941. Nephroscopy with removal of stone following nephrostomy for obstructive calculous anuria. J. Urol. 46, 177–182). Fernstrom and Johansson first described the extraction of kidney stones through a percutaneous tract created for this purpose by minimally invasive methods (Fernstrom, I., Johansson, B., 1976. Percutaneous pyelo-lithotomy. A new extraction technique. Scand. J. Urol. Nephrol. 10, 257–259). Subsequently, the method was widely popularized in the 1980s by Wickham and Kellet in Great Britain and by Alken in Germany. It gradually gained ground, the indications diversified, and in 2005 the American Urology Association included in its guidelines, the recommendation to use percutaneous nephrolithotomy as the first line of treatment for staghorn calculi (Preminger, G.M., Assimos, D.G., Lingeman, J.E., Nakada, S.Y., Pearle, M.S., Wolf, Jr., J.S., 2005. Chapter 1 AUA guideline on management of staghorn calculi: diagnosis and treatment recommendations. J. Urol. 173 (6), 1991–2000).

Urine cell-based DNA methylation classifier for monitoring bladder cancer

BackgroundCurrent standard methods used to detect and monitor bladder cancer (BC) are invasive or have low sensitivity. This study aimed to develop a urine methylation biomarker classifier for BC monitoring and validate this classifier in patients in follow-up for bladder cancer (PFBC).MethodsVoided urine samples (Nu2009=u2009725) from BC patients, controls, and PFBC were prospectively collected in four centers. Finally, 626 urine samples were available for analysis. DNA was extracted from the urinary cells and bisulfite modificated, and methylation status was analyzed using pyrosequencing. Cytology was available from a subset of patients (Nu2009=u2009399). In the discovery phase, seven selected genes from the literature (CDH13, CFTR, NID2, SALL3, TMEFF2, TWIST1, and VIM2) were studied in 111 BC and 57 control samples. This training set was used to develop a gene classifier by logistic regression and was validated in 458 PFBC samples (173 with recurrence).ResultsA three-gene methylation classifier containing CFTR, SALL3, and TWIST1 was developed in the training set (AUC 0.874). The classifier achieved an AUC of 0.741 in the validation series. Cytology results were available for 308 samples from the validation set. Cytology achieved AUC 0.696 whereas the classifier in this subset of patients reached an AUC 0.768. Combining the methylation classifier with cytology results achieved an AUC 0.86 in the validation set, with a sensitivity of 96%, a specificity of 40%, and a positive and negative predictive value of 56 and 92%, respectively.ConclusionsThe combination of the three-gene methylation classifier and cytology results has high sensitivity and high negative predictive value in a real clinical scenario (PFBC). The proposed classifier is a useful test for predicting BC recurrence and decrease the number of cystoscopies in the follow-up of BC patients. If only patients with a positive combined classifier result would be cystoscopied, 36% of all cystoscopies can be prevented.

Chapter 3 – Instruments

The instruments used for the ureteroscopic approach of upper urinary tract conditions are in a continuous evolution. The first ureteroscopes were too large in diameter, their use being restricted to a small number of patients. Moreover, the methods for stone fragmentation or extraction, as well as for tissue resection/fulguration, were limited. Subsequently, the instruments evolved and the technique improved, the ureteroscopes allowing the use of an increasing number of accessory instruments, in the conditions of a decreasing diameter. The development of rigid and flexible ureteroscopes with increasingly smaller dimensions determined the diversification of transurethral upper urinary tract endoscopy.

Chapter 4 – Diagnostic Ureteroscopy

In selected cases in which clinical, laboratory, and/or imagistic data are equivocal, establishing a correct diagnosis may require the endoscopic exploration of the upper urinary tract. Due to the complexity of the spatial distribution of the renal pelvis and the calyces, rigid or semirigid ureteroscopy does not allow for the exploration of the entire upper urinary tract in the vast majority of cases. n nThe use of flexible ureteroscopes has made possible, at least in theory, the minimally invasive approach of the upper urinary tract and its systematic exploration at any level, becoming not just an efficient therapeutic instrument, but also a very useful component of the investigation protocol.

Chapter 12 – Ureteroscopy in the Treatment of Iatrogenic Injuries

Iatrogenic ureteral lesions can occur as a complication of abdominal surgical procedures, but in most cases they are due to pelvic or retroperitoneal interventions. The widespread use of ureteroscopic and laparoscopic interventions has led to an increase in the incidence of secondary ureteral injuries.

Chapter 8 – Percutaneous Nephrostomy

Percutaneous nephrostomy is a minimally invasive method for the external drainage of the upper urinary tracts, performed under ultrasonographic or fluoroscopic guidance. The purpose of the method is, first, to decrease the pressure and distension of the pyelocaliceal system, together with gaining an antegrade access to the upper urinary tract to perform different diagnostic and therapeutic procedures.

Chapter 11 – Percutaneous Approach of Upper Urinary Tract Iatrogenic Lesions

Abstract The intensive development of new therapeutic methods and techniques, associated with the appearance of high-quality and reliable instruments, has not been able to completely prevent upper urinary tract injuries due to the surgical act. Minimally invasive percutaneous approach remains a first-line treatment solution for these injuries, regardless of their etiopathogeny: after open surgical procedures, endoscopic (retrograde or percutaneous) interventions, or those secondary to the placement of urinary stents.

Percutaneous Approach in Renal Lithiasis

Abstract Since the first description of percutaneous nephrolithotomy (PCNL), the indications for percutaneous approach have suffered significant changes as a result of increased experience, technological evolution, economical factors, and patient preferences. Although the use of less invasive methods, especially of extracorporeal lithotripsy, but also of retrograde flexible ureteroscopic approach, has limited the indications for percutaneous surgery for this condition, PCNL has maintained its role in the first-line treatment of voluminous complex renal lithiasis, of lithiasis resistant to extracorporeal fragmentation, or of lithiasis occurring on malformed kidneys. Many factors are involved in establishing the therapeutic indication for renal stones: number, size, composition (evaluated by Hounsfield units) and location of the stones, the presence of hydronephrosis, caliceal diverticula, pyeloureteral junction stenosis, or renal malformations. In addition to the elements related to lithiasis characteristics, a number of general factors are also involved in establishing the therapeutic indication: the patient’s profession, obesity, skeletal anomalies, comorbidities or previous interventions, the presence of urinary diversions, etc.

Percutaneous Approach of Renal and Perirenal Suppurations

Abstract Renal abscess is a circumscribed suppurated collection in the renal parenchyma. Although ascending urinary tract infections with Gram-negative germs seem to be responsible for most cases of renal abscesses in adults, another modality of septic seeding can be the hematogenous one. Modern diagnostic methods and interventional radiological techniques have modified the therapeutic management of renal abscesses in the last decades. For selected cases of renal abscesses, percutaneous treatment combined with antibiotic therapy represents the standard therapy to date, with a decrease in morbidity, mortality, hospitalization period, and costs. Percutaneous drainage represents an efficient and safe alternative to open surgical drainage. When it is not curative, percutaneous treatment may allow the stabilization of the patient until the curative intervention.

Chapter 2 – Fluorescence Cystoscopy

Fluorescence is defined as the property of a structure to emit light without a noticeable delay when irradiated. According to Stoke’s law, the light emitted has a higher wavelength than the absorbed light, while the photons are characterized by a low level of energy. n nThe fluorescent emission from untreated materials is known as primary, natural fluorescence, or autofluorescence. When fluorescence is generated artificially by the use of additional fluorescent substances, secondary fluorescence occurs. Haitinger (1959) called these materials “fluorochromes” to distinguish them from other dyes used in visible light microscopy.