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Specialist care following (nephron-sparing) kidney surgery serves to detect postoperative complications and to monitor kidney function and cardiovascular health. From an oncological point of view, the early detection of local and contralateral recurrences as well as (single) distant metastases in the early disease stages is paramount. This enables the option of metastasis-directed surgery to delay systemic therapies. On the other hand, the early detection of distant metastases can facilitate the initiation of necessary systemic therapies. In general, nephron-sparing surgery is recommended as the first-line treatment of choice for localized renal tumors. Current guidelines recommend a risk-adapted follow-up based on histopathological criteria (pT, pN or R status). For patients with intermediate and high-risk findings, aftercare should be intensified. In addition to routine blood tests, cross-sectional imaging using contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) remain the method of choice. Recently presented results of the phase III KEYNOTE-564 study on the adjuvant therapy with the programmed cell death 1 (PD1) inhibitor pembrolizumab in clear cell, locally advanced renal cell carcinoma (≥ pT1 GII and or ≥ N+) or oligometastatic renal cell carcinoma without evidence of distant metastases (e.g., after metastasis surgery 1 year after nephrectomy) demonstrated an advantage in terms of disease-free survival compared to follow-up alone. However, overall survival results are pending. Other potentially effective adjuvant concepts including atezolizumab, nivolumab/ipilimumab, everolimus or pembrolizumab/belzutifan are currently being investigated in clinical trials.Die fachärztliche Nachsorge nach Nieren(teil)entfernung dient der Entdeckung postoperativer Komplikationen sowie langfristig dem Monitoring der Nierenfunktion und der kardiovaskulären Gesundheit. Aus onkologischer Sicht ist die frühzeitige Detektion lokaler und kontralateraler Rezidive sowie (singulärer) Fernmetastasen im Frühstadium im Vordergrund. Zum einen ermöglicht dies den Einsatz der Metastasenchirurgie, um ggf. eine Systemtherapie hinauszuzögern, zum anderen kann die Erkennung von Fernmetastasen die frühzeitige Einleitung notwendiger Systemtherapien erleichtern. Im Allgemeinen wird die Nierenteilresektion als Primärtherapie der Wahl zur Behandlung lokal begrenzter Nierentumoren empfohlen. Entsprechend histopathologischer Kriterien (pT-, pN- oder R‑Status) wird eine risikoadaptierte Nachsorge empfohlen. Ab intermediärem Risiko sollte eine intensivierte Kontrolle durchgeführt werden. Neben Routineblutuntersuchungen ist die schnittbildgebende Nachsorge mithilfe kontrastmittelgestützter Computertomographie (CT) oder Magnetresonanztomographie (MRT) Mittel der Wahl. Kürzlich vorgestellte Ergebnisse der Phase-III-KEYNOTE-564-Studie zur adjuvanten Therapie mit dem programmed cell death 1(PD1)-Inhibitor Pembrolizumab bei klarzelligen, lokal fortgeschrittenen Nierenzellkarzinomen (≥ pT1 GII und oder ≥ N+) oder oligometastasierten Nierenzellkarzinomen ohne Nachweis von Fernmetastasen (z. B. nach Metastasenchirurgie 1 Jahr nach Nephrektomie) zeigen einen Vorteil in Bezug auf das krankheitsfreie Überleben im Vergleich zur alleinigen Nachsorge. Die finalen Ergebnisse zum Gesamtüberleben sind bislang ausstehend. Weitere Alternativen mit Atezolizumab, Nivolumab/Ipilimumab, Everolimus oder Pembrolizumab/Belzutifan werden aktuell im Rahmen klinischer Studien geprüft.

Solid renal masses are increasingly treated with nephron-sparing surgery. As in other uro-oncological surgical techniques, minimally invasive and robotic-assisted techniques are becoming increasingly popular.The perioperative results from minimally invasive nephron-sparing surgery versus open surgery were retrospectively compared.In our single center retrospective study, all patients who underwent nephron-sparing tumor excision between 2006 and 2016 were divided into two groups (group O = open approach and group M = minimally invasive approach). The (pre-)operative data, complications, and change in renal function were compared. Trifecta criteria (R0, no perioperative complications, ischemia ≤25 min) were used to determine success rates.Of 329 patients, 310 were included for analysis (group O 123, group M 187). Patients in group O had significantly worse ASA score but comparable Charlson Index and significantly more pT3/4 tumors but equal PADUA-score when compared with group M. Otherwise, preoperative patient and tumor characteristics were comparable. Patients in group M had significantly shorter hospital stays (p 0.001) and lower transfusion rates (p 0.05). Trifecta criteria were more frequently met in group M than in O (M: 66.8% vs. 0: 49.6%; p 0.001). Both major and minor complications were lower in group M (major: 10.7% vs 17.1%; minor: 13.9% vs. 26.0%; p 0.05). Preservation of renal function was comparable in both groups. R0 rates did not differ significantly between groups (M: 97.8% vs O: 97.5%). Surgical procedure times were significantly longer in group M (p 0.001; mean 30 min).Minimally invasive, robotic assisted partial nephrectomy also proved to be successful in complex cases. In all aspects studied, the minimally invasive approach was shown to be at least equivalent to the open approach.

Several new treatment strategies have emerged in the treatment of small renal masses (4 cm in diameter). Active surveillance and ablative techniques have been introduced but it remains unclear which patients will benefit the most from these new treatment options. A surgical approach remains standard of care. In recent decades, radical nephrectomy has been replaced by nephron-sparing surgery for the management of small renal masses.In addition to the open partial nephrectomy, which is considered the standard approach, the number of surgeries performed using minimally invasive techniques is increasing. Recent data show that there might be some benefits such as less blood loss. The disadvantages shown by laparoscopic partial nephrectomy such as prolonged warm ischemia, longer operation times, and postoperative renal impairment might be negligible for the robotic approach. Therefore, current guidelines allow these approaches in addition to open partial nephrectomy if sufficient surgical expertise is given.

The indications for nephron-sparing surgery have been considerably extended by guideline recommendations in recent years. It remains unclear whether clinical practice still reflects these new guidelines.In this retrospective, monocentric analysis at a tertiary referral center the indications for partial nephrectomy over a 13-year period were evaluated.In a retrospective database analysis all cases of surgically treated renal masses from 2001 to 2013 were evaluated. Besides demographic, tumor-specific and perioperative variables the development of the surgical technique depending on the tumor stage was evaluated.The proportion of nephron-sparing surgery cases increased from below 20 % in 2001 to 35 % in 2013 in the entire cohort. For stage T1a tumors, partial nephrectomy increased from approximately 50 % to over 90 % and for T1b tumors it rose from 10 % to 50 %. Logistic regression revealed stage 1 tumors to be predictive of partial nephrectomy over the complete evaluation period. Extending the indications for partial nephrectomy even to higher stages is under discussion but not yet supported by data from prospective, controlled studies.

Renal cell carcinoma represents more than 90 % of all malignant kidney tumors. International guidelines for follow-up examinations after surgery for kidney tumors are still incomplete. New challenges are arising because of growing use of nephron sparing surgery. According to well-known prognosticators risk-adapted follow-up strategies may be established that are stratified into 3 risk groups.

Human actinomycosis is an infrequent chronic infection caused by gram-positive anaerobic bacteria with predominantly cervicofacial and intestinal manifestation. Retroperitoneal abscess formation displays a very rare localisation and is mostly incidentally diagnosed by histological examination. We report on a 44-year-old woman with left-sided flank pain and retroperitoneal abscess formation diagnosed by CT scan. Case history revealed preceding nephroureterectomy of the left kidney due to loss of kidney function and recurrent ureteral-vaginal fistulas. After CT scan-guided puncture and negative bacterial culture, actinomycosis could only be diagnosed by histopathological examination. Subsequently, besides abscess drainage calculated antibiotic therapeutic regimen was initiated. During the follow-up of 9 months there was no local or systemic recurrence. In the present case report, aetiology, clinical symptoms as well as diagnostic and therapeutic consequences are discussed.

Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches.

In this article up-to-date, nephron-sparing therapy for renal cell cancer such as radical tumor nephrectomy, partial resection or enucleation is summarised. The results of open and laparoscopic partial nephrectomy and tumor enucleation are presented. Problems and complications associated with the techniques are reviewed. There are as yet no randomized, controlled trials and most published studies show retrospective data. Further new alternative techniques in nephron-sparing therapy like cryosurgery and radiofrequency ablation are presented.

The regulation of blood pressure is a complex process, involving several organs. The kidney plays a major role and is involved in the initiation and maintenance of hypertension. Mechanisms involved are: (1) the sympathetic nerveous system, (2) the renin-angiotensin system, (3) the regulation of sodium and water balance, (4) the production of vasoactive substances such as endothelin, adenosine or nitric oxide (NO), and (5) structural alterations such as a reduced number of glomeruli and nephrons. Several therapeutic intervention strategies affecting these mechanisms have already proven to be effective antihypertensive drugs.

Nephron-sparing surgery of renal cell carcinoma in the 1970's and 1980's in patients with bilateral renal tumors or reduced renal function (imperative indication) has shown a very low risk of recurrent cancer. Today, nephron-sparing surgery in renal cell carcinoma is considered in an increasing number of patients with expected sufficient renal function after nephrectomy (elective indication). Resection technique, the use of Tabotamp(R) to reduce bleeding, and pseudotumors do complicate the interpretation of the images. It has been not yet defined which diagnostic modality is best suited for follow-up after renal cell carcinoma resection. Follow-up protocols in different institutions show a wide variety. The follow-up of patients after nephron-sparing surgery is performed by annual sonography or MRI every three months. Up to now, CT and ultrasound are the standard methods. MRI with its multiplanar imaging and improved soft tissue contrast seems to have an equal diagnostic value. Additionally, MRI seems to be suited for patients with reduced renal function. The aim of this paper is to give guidelines for the radiologist to understand the different surgical procedures and to evaluate the postoperative findings. Different imaging modalities in the follow-up of patients and special radiological phenomena are discussed.

After a controversial phase of nomenclature (including--among others--the terms "hypernephroma" and "hypernephroid carcinoma") a cytomorphologically defined subtyping of renal cell tumours (adenomas, carcinomas, oncocytomas) is offered, based on new electron microscopical and histochemical observations. These data are in part supported by cytogenetical findings reported in the literature. Phenotypical/histogenetical relations to different parts or cell types, respectively, of the nephron-collecting duct system could be demonstrated. Chromophobe cell carcinoma and oncocytoma exhibit features of the intercalated cells.

The kidney is a composite organ, the specific activities of which are attributable to the peculiar construction of the individual components of the glomerula, nephrons and collecting tubules. This comprehensive review will address the essential physiological mechanisms of urine formation, such as filtration, secretion, reabsorption and concentration, and correlate these functions to morphological structures where possible. The complex structure of the renal glomerulus as the basis for the formation of primary urine (blood-urine barrier) will be documented on the basis of electron micrographs. In addition to this, the ultrastructure of the epithelium in the various tubular segments and collecting tubules will be discussed from a histophysiological stand-point, including its significance in the excretion of waste substances and maintenance of a constant fluid environment in the body (Homeostasis).

A dualistic function for the natriuretic ATP.inhibiting factor is formulated on the basis of a phenomenon like compensatory renal adaption of residual nephrons: 1. Support of the tubular sodium excretion to the maintenance of homoeostasis of the organism. 2. Inhibition of the forced up vasodilation of the afferent glomerular vessel. It should suggested that the renal vasoconstrictive effect is a part of a protective system for residual nephrons against the pathogenic hyperfiltration and hyperperfusion.

Glomerular filtration and tubular reabsorption of endogenous serum proteins were measured using micropuncture technique in the rat kidney. Data resulting from experiments on the single nephron level are compared with human overall kidney function. Reabsorption of filtered protein was virtually complete (84 to 96%) at endogenous serum levels. Tubular reabsorption capacity is almost reached under control conditions. In human infants, tubular protein reabsorption capacity increases with maturation.

Researches about the Activity of some Dehydrogenases in the Nephrons of Desert Rats (Meriones unguiculati).--Our desert rats Meriones unguiculati (Mongolian Gerbils) show--also when held under the same experimental conditions as our other laboratory rodents (Wistar rats and white mice)--a somewhat different enzyme histchemical behaviour of these nephrons. The essential difference in the Meriones is that their distal convolutions display on the whole stronger enzyme activities compared as well with the proximal convolutions of the same kidneys, as with the distal convolutions of Wistar rats.

A few years ago the kidney in chronic renal failure was described as a mass of tissue "without significance, vanishing into the disparity of thousands of fantastically altered organs of strange design and anomalous behaviour". In order to refute this opinion, some of the morphological and pathophysiological evidence is summarized which points to the fact that even in chronic renal failure the remaining nephrons that contribute to renal function behave as a rather homogeneous population characterized by appropriate adaptations of glomerular and tubular functions and by a persistent responsiveness to the changing needs of the patient.

In 21 normal dogs of different breeds and ages the number of nephrons was calculated from paraffin sections in comparison with a maceration method. With these methods the number of glomeruli x 1000 per kidney appeared to be 502 +/- 213 and 515 +/- 230 respectively. The histological method appeared to be acceptable for the determination of the number of glomeruli in incomplete kidneys. The examined Cocker Spaniels consisted of 5 animals without renal problems for control and 21 animals with nephropathy: 12 of 1-2 years, 6 of 4-6 years and 3 of 9-10 years old dogs. As indication for the present number of nephrons the glomeruli were counted in bands of whole cortex with a width of 1 mm. The number of glomeruli per band of cortex in the nephropathic Cocker Spaniels (15.0 +/- 3.0) was not drastic lower than those of the normal Cockers (20.8 +/- 2.5) and of 7 normal adult dogs of different breeds (17.2 +/- 2.2). On pathological examination the nephropathic kidneys showed a membranoproliferative-sclerosing glomerulonephritis with extra-capillary reaction leading to glomerular obsolescence. The animals showed evident proteinuria and final renal insufficiency. It was concluded that the pathogenesis of the familial nephropathy in this breed will not be caused by cortical hypoplasia, but by a primary glomerulopathy.

The influence of a regular physical training after unilateral nephrectomy carried out on the experimental animal rat on the function of the residual kidney was investigated. A significant decrease of the glomerular filtration rate by 22% and an increase of TmPAH by 36% in the loaded animals could be proved 12 weeks after unilateral nephrectomy and two-month load by swimming training. These findings allow the interpretation that physical conditioning for adapting nephrons may be regarded as progression as well as protection factor. Additional long-term investigations are necessary to clarify this problem and finally to prove present therapeutic recommendations for the physical conditioning with regard to prove protective reactions to the renal compensatory adaptation of the residual nephrons without any doubt.

The kidneys of female Sprague Dawley rats were examined by electronmicroscopical and histochemical methods after intoxication with O-pinacolyl-methyl-phosphonylfluoride. The same explorations were made with control animals, with animals after hypoxia for 24 h, and starving for 36 h. The epithelial cells of the proximal and distal convoluted tubule cells showed the following changes: In the epithelial cells of the basal labyrinth there was a striking extention. The swelling of the intercompartmental space were discussed in connection with a restricted return of sodium-resorption. Further changes in the epithelial cells of the two nephron-segments after organophosphat-intoxication are the swelling of the mitochondria, the reduction of the cristae up to the total destruction of these mitochondria, the formation of myelin-figures, the swelling of the ER and the GOLGI complex.

The expression of intermediate filament (IF) proteins (vimentin and individual cytokeratins [CKs]) has been studied in the normal human kidney using immunohistochemical methods. For CKs 19 and 7, a conspicuously alternating pattern of positive and negative tubule segments was found, suggesting an inverse relationship between epithelial specialization and extent of the CK cytoskeleton. Coexpression of CKs and vimentin (typical of the common types of renal cell carcinomas) was found in fetal but not in adult proximal tubules. The surface epithelium of the adult renal papilla was characterized by the presence of basal cells expressing certain stratification-related CKs. These data underline the correlation of IF protein expression not only with the epithelial cell type but also with its developmental and functional state.

Residual nephrons are subject to compensatory adaptation at which the glomerular hyperfiltration and convection of macromolecules (proteins) are of pathogenic character in the progression of nephropathy. The influence of indomethacin at dosages of 2 or 3 mg/kg body weight/day was investigated in long-term feeding trials (8 months) on inbred female Wistar rats after unilateral nephrectomy and additional resection of both kidney poles. The results show a significant deterioration of vital prognosis under indomethacin medication independently of the dosage.

Kidney biopsy specimens of three patients with a special form of hypoplasia, the oligomeganephronic hypoplasia (Oligomeganephronie) were studied with light- and electron-microscopy as well as morphometric methods. The morphometric measurements demonstrated that there were no quantitative differences of the glomerular components between normal and oligomeganephronic glomeruli of patients of the same age. All of the structures measured--glomerular capillary surface, glomerular volume, volume of the glomerular capillary lumina and volume of Bowman's capsular space--were increased about 5.4 times. The volume of the proximal and distal tubules per mum tubular length in oligomeganephronic patients was disproportionally increased. The total number of glomeruli was more diminuished than mentionned in the literature until this time. The secondary glomerular sclerosis, initially focal, was progressive and supposed to be caused by "chronic overwork".