Calyx Group Research Articles

Factors and nomograms determining the effectiveness of extracorporeal shock wave lithotripsy in children with urolithiasis: a literature review

Extracorporeal shock wave lithotripsy (ESWL) is currently the priority method for treating urolithiasis in children. Due to the lack of extended indications for the application of this technique, an active search has been made over the past 30 years to define factors predicting ESWL outcome, to create objective preoperative planning tools, to increase ESWL effectiveness and to reduce the number of anesthetics and unnecessary surgical interventions. Search for the information on predictive factors of ESWL successful intervention and on modern statistical tools predicting lithotripsy effectiveness in children with urolithiasis was made in foreign and domestic sources, like MEDLINE, eLIBRARY, CyberLeninka. The literature analysis has showed that the following factors predispose positive ESWL outcomes: age before six years, smaller calculi size, and shorter skin-to-stone distance. Stone location in the lower calyx group, multiple concrements, and their high density has a negative impact at complete fragment detachment after ESWL. The probability of complete detachment of stone fragments from the lower calyx group decreases under the following anatomic features of kidney collecting system: number of draining calyces is more than one, calyx neck diameter is less than 4 mm, acute angle between the lower infundibulum and renal pelvis. Body mass index and prestenting have a controversial effect at successful ESWL too. Nomograms and scoring systems based on predicting factors are widely used in both adult and pediatric practice. The two most commonly used nomograms in pediatric urology are Onal and Dogan nomograms developed in 2012 and 2015 in Turkey. These nomograms include the following parameters: patient's sex and age, history of ipsilateral surgical interventions as well as stone localization, number and size. Thus, predicting ESWL outcomes using preoperative planning allows to choose the most appropriate treatment modality for a particular patient considering his/her individual anatomical and physiological characteristics and characteristics of the calculi.

The 1-cm lower calyx calculus: SWT, URS or Mini-PCNL? Guidelines vs. reality.

Urinary stones of the upper urinary tract can be considered a widespread public health concern due to their high incidence and prevalence and their health policy-related and financial implications. A significant proportion of newly diagnosed kidney stones are lower-pole stones, i.e., stones affecting the lower calyx group of the renal pelvicalyceal system. These are often diagnosed by chance, i.e., as incidental findings during ultrasound or CT scans performed for other reasons, or as "secondary stones" detected during the diagnostic work-up of symptomatic urinary stones in other locations. Residual disintegrates after extracorporeal shock-wave lithotripsy (ESWL) or endoscopic stone therapy constitute a further, quantitatively significant group. These incidentally discovered lower-pole stones are often characterised by their small size and lack of symptoms. It stands to reason that some of these small, asymptomatic lower-pole stones do not always remain small and asymptomatic, and that treatment tends to become more complex with increasing size. There has been an astonishing lack of published studies with a high level of evidence over the last 20 years to provide a conclusive and reproducible answer to the question posed in this review. Small, asymptomatic stones can be monitored. Symptomatic and rapidly growing stones should be treated. There is a lack of valid risk factors allowing an identification of subgroups that should be treated prophylactically at the asymptomatic stage. In active therapy, a 10-to-20-year-old principle still holds true today: a high stone-free rate in one therapy session is offset by an increased complication rate, with increasing miniaturisation in endourology (retrograde and percutaneous) and increasingly effective laser disintegration shifting this basic principle more and more in favour of flexible URS and (mini, micro) PCNL. The range of indications for ESWL is undoubtedly becoming smaller, and this also applies to lower-pole stones. The results of an ongoing prospective randomised study comparing the different treatment modalities, albeit with recruitment difficulties, are still pending.

Classification and clinical significance of the posterior group of renal calyces.

To study the anatomical orientation of the posterior group of calyces based on reconstructed images of computerized tomography urography (CTU) and provide a novel classification with its clinical significance. Clinical data of a total of 1321 patients, who underwent CTU examination in our hospital were retrospectively analyzed. Among these, a total of 2642 3-dimensional reconstructed images of CTU scans were considered in this study. Based on the morphology of the renal calyces and the influence on the establishment of surgical access, the posterior group renal calyces are classified into 3 major types including pot-belly type, classically branched and elongated branched. The classically branched type is further classified into 3 sub-types: a, b and c, based on the association of minor calyces of the posterior group to the major calyces. Type a is derived from 1 group of major calyces only, type b is derived from 2 groups of major calyces simultaneously, and type c is derived from 3 groups of major calyces simultaneously. Statistical findings revealed that all kidneys possess posterior group calyces. The percentage of occurrence of pot-belly type, classically branched and elongated branched is 8.06%, 73.13%, and 18.81%, respectively. The anatomical typing of the classical branching type occurred in 19.36%, 68.17%, and 12.47% for types a, b, and c, respectively. In this study, the posterior group calyces were found to be present across all patients. The posterior group calyces were highest in the classical branching type, of which anatomical typing was highest in type b. The typing of the posterior group of calyces could provide an anatomical basis for percutaneous nephrolithotomy (PCNL) puncture from the posterior group.

The Modified Procedure of Totally Tubeless PNL

Mini percutaneous nephrolithotomy (mPNL) is a standard treatment for kidney stones larger than 1.5 cm, with the placement of a nephrostomy drainage at the end of it, which is considered the standard procedure, but tubeless/ totally tubeless mPNL techniques reduce postoperative discomfort in patients and shorten hospital stays. The aim of article was to compare the efficacy and safety of our proposed modified method of totally tubeless mPNL with control of the parenchymal canal, with existing methods of tubeless/totally tubeless mPNL. Novelty of the study presented by modified method of totally tubeless mPNL. During the period from 2018 to 2020 we performed 486 mPNL were performed in our clinic in total, among which 63 (12.9%) patients underwent tubeless PNL. Patients whose surgeries ended with using tubeless techniques were divided into three groups: Group I – 22 patients who had tubeless mPNL (with ureteral stent), Group II (20 patients) – totally tubeless mPNL with a safety thread (the proposed procedure), Group III (21 patients) – totally tubeless mPNL. In all three groups, the access point was most often made through the lower group of renal calyces: Group I – 12 (54.5%), Group II – 14 (70.0%), Group III – 13 (61.9%); then through the middle calyx: Group I – 8 (36.4%), Group II – 6 (30.0%), Group III – 7 (33.3%); and the upper calyx: Group І – 2 (9.1%), Group ІІ – 0%, Group ІІІ – 1 (4.8%), no differences in the distribution of access points between groups were found (p=0.67). There were no differences in the distribution of tract sizes between the groups (p=0.95) with tract dilatation to 16.5/17.5 Fr was performed most often: Group I – 12 (54.5%), in Group II – 11 (55.0%) and Group III – 11 (52.4%). The mean duration of surgery in Group I was 83.0±22.9 min, in Group II – 74.9±13.6 min, in Group III – 72.6±12.0 min (p=0.47). This study confirms the high effectiveness of totally tubeless mPNL. The proposed modification to perform totally tubeless mPNL allows you to have permanent postoperative control over the parenchymal channel and in case of postoperative bleeding it enables you to immediately insert nephrostomy drainage through the safety thread. Study contributes to practical methods as an intermediate step for surgeons who are considering transition to a totally tubeless PCNL technique.

A case of open surgical treatment of staghorn calculus in a patient with factor VII deficiency

The paper presents a clinical case of treatment of staghorn nephrolithiasis complicated in the postoperative period by bleeding caused by a latent deficiency of factor VII of the blood coagulation system. Often the disease is latent and is detected in serious injuries or during the surgeries. Sometimes the diagnosis is made in profuse bleeding. Under endotracheal anesthesia, the left-sided nephrolithotomy and intrarenal stenting with clamping of the renal artery was performed. The time of clamping of the renal artery was 12 minutes. Before clamping the renal artery, 3 mg of furosemide 0.2 mg of verapamil and 1 mg of methylethylpiridinol were introduced intravenously per kilogram of patient' weight. A stone sized 3.02.5 cm was removed from the kidney, and a number of small stones were washed out from the lower group of calyces. At the time of diagnosis, prothrombin time and prothrombin index were checked. The patient's hemostasis system, including clotting factors, were examined. The results showed that the patient's blood clotting time by LeeWhite method increased to 15 minutes (reference, 713 minutes), and the time of activated partial thromboplastin time (aPTT) to 41.6 seconds (reference, 2838 seconds), while the activity of factor VII decreased to 40% (reference, 70120%). After that, the patient was diagnosed with factor VII deficiency or hypoproconvertinemia. During treatment, the patient was transfused twice a day with fresh frozen plasma and only once during the entire period, 1000 IU of antiinhibitoty coagulant complex (FEIBA) was administered intravenously. From the first day of treatment hematuria decreased, there was a reverse development of hemorrhagic syndrome. Obvious and latent comorbidities before and after the surgery should not be left out without attention. Only in this case it is possible to successfully complete the treatment and achieve the correct results.

Extraosseous abnormalities and artifacts in skeletal scintigraphy

to specify frequency, patterns and diagnostic significance of extraosseous soft tissue findings in 99mTc-pyrophosphate skeletal scintigraphy. Results of skeletal scintigraphy from 1060 patients (447 men, 613 women) were analyzed. Scanning in "whole body" mode started in 3-4 hours after 740 MBq of radiotracer activity intravenous administration, and performed in anterior and posterior projections in continuous table motion mode at rate of 6-8 cm per minute. Single photon emission computed tomography/computed tomography (SPECT/CT) was additionally performed when necessary. Extraosseous scintigraphic findings were discovered in 161 (15.2%) patients, they can be divided into three categories: nephrourological (7.7%), soft tissue (5.4%) and artifacts (2.1%). First category included anatomical and functional changes in the urinary system (kidney location anomalies and nonobstructive uropathies). SPECT/CT was performed to differentiate calycostasis in the projection of the upper group of calyces and focal changes of the ribs. Soft tissue extrarenal findings included diffuse or focal RP hyperfixation within breasts (29 patients), thyroid glands (15), myocardium (5), scrotum (4) and abdominal cavity (4). Symmetrical increased RP accumulation in breast or thyroid lobes was accepted as normal. Pathologic soft tissue findings in 11 patients were verified by history or instrumental data: breast cancer (2), testicular cancer (1), nodular goiter (2), uterine fibroids (2), primary cancer with liver metastases (1), association of "hot kidney" phenomenon with chemotherapy (2), and "superscan" phenomenon with myelofibrosis (1). Causes of radiotracer artifacts in the liver and spleen (14) were of radiopharmaceutical factors, in axillary lymph node (7)--partially infiltrative radiopharmaceuticals administration, in the colon (1)--previous myocardial perfusion scintigraphy. Analysis and interpretation of abnormal extraosseous findings in skeletal scintigraphy is an essential component of additional diagnostic information, that can influence subsequent diagnostic and therapeutic tactics.

Middle calyx access in complete supine percutaneous nephrolithotomy

Background: Middle calyx access has been underused in percutaneousnephrolithotomy (PCNL), especially in the supine position.We compared the safety and efficacy outcomes between middlecalyx and lower calyx accesses in the complete supine PCNL in anon-randomized single-surgeon clinical study.Methods: Between February 2008 and October 2011, 170 patientsunderwent posterior subcostal single tract complete supine PCNLwith one-shot dilation and middle calyx (n = 48) and lower calyx(n = 122) accesses. Stone location and surgeon decision determinedtarget calyx for access. Inclusion criteria were pelvis stones,staghorn stones and multiple location stones. Exclusion criteriawere renal anomalies, only upper calyx stones, only middle calyxstones and only lower calyx stones. Important parameters werecompared between the two groups. A p value of <0.05 was consideredsignificant.Results: Two groups were similar in important patient- and stonerelatedparameters. Mean operative time (60.7 minutes), meanpostoperative hospital stay (1.84 days) and mean hemoglobin drop(0.67 g/dL) in the middle calyx group were significantly lesser thanin the lower calyx group (80.1 minutes, 2.19 days, 1.36 g/dL). Themiddle calyx group (89.6%; 79.6%) had a higher stone-free rate(p = 0.054) and efficiency quotient than the lower calyx group(76.2%; 61.6%). In the middle calyx group (10.4%; 2.1%), complicationand transfusion rates were lesser (p > 0.05) than lowercalyx group (14.8%; 7.4%). No significant difference (p = 0.40)was seen between two groups using the modified Clavien classificationof complications.Interpretation: Middle calyx can be an optimal access in PCNLwith the complete supine position for many of upper urinary tractstones due to its superior outcomes.

Computed Tomography of Renal Tuberculosis and Its Pathological Correlates

Computed tomographic studies of eight patients with proven renal tuberculosis demonstrated a spectrum of findings related to the extent and the severity of kidney involvement. In early or focal disease, obstruction of a single major calyx or a group of minor calyces was noted (four cases) with no excretion of contrast material into the affected calyces (three cases) and cortical thinning. Tuberculosis of the renal pelvis (five cases) was manifested by either pelvic dilatation secondary to ureteropelvic junction obstruction (three patients) or diffuse pelvic contraction (two patients). In far advanced disease (four cases) the kidneys were small and exhibited atrophy with replacement of parenchyma by one or more low density areas. Calcifications (37.5%) were identified in the parenchyma and within the calyces. Computed tomography may provide the first clue in suggesting the inflammatory nature of a renal mass and excluding a neoplastic process. Computed tomography is also of value in determining the full extent of extrarenal involvement and the amount of residual functioning parenchyma, both of which are critical in proper treatment planning.

Intrarenal reflux--papillary morphology and pressure relationships in children's necropsy kidneys.

A radiological study of the necropsy kidneys of 100 children was made. Morphologically it was shown that compound or fixed papillae predominate in the upper group of calyces and to a lesser degree in the lower group, whilst simple papillae occurred in the middle group. Pressure studies showed that intrarenal reflux occurred in compound papillae at lower pressure than in simple papillae and that lower pressures were required to produce intrarenal reflux in the first year of life.

Upper clayx reno-vascular obstruction in children: Fraley's syndrome

Intrarenal vascular obstruction of the upper calyceal infundibulum has been distinguished by Fraley as an entity separate from an asymptomatic vascular impression. Clinically, this form of intrarenal vascular obstruction presents as nephralgia or hematuria. This infundibular obstruction is caused by normal renal vessels, usually the upper segmental artery: radiologically, the vessels produce a constant well-defined filling defect in the infundibulum at IVP, and, the upper calyx group is distended and shows delay in emptying. We found this condition in 14 children from 1968-1975. Control studies showed no progression in the radiological findings, even over a long period. In one of our cases angiography was indicated to exclude tumour or cyst; in another case, surgery was necessary. Complications are urinary tract infection or stone formation. Therefore, children with Fraley's syndrome require regular clinical examination.

The prone position in intravenous urography for study of the upper urinary tract.

Intravenous urography is usually carried out with the patient recumbent, in the face-up position. Occasionally, for visualization of anterior and posterior borders of the kidney, oblique-supine and recumbent lateral views are used. An erect anteroposterior projection is sometimes added to the routine to determine mobility of the kidneys, emptying of the renal pelves and the ureters, and possible laxity of the pelvic floor. A recumbent postero-anterior study is not commonly included in intravenous urography, although such a view can in some instances add valuable information. Urine containing the commonly used contrast materials is of higher specific gravity than non-opacified urine because of the relatively high specific gravity of the medium. Thus, 50 per cent Hypaque solution has a specific gravity of 1.32, and 76 per cent Renografin solution has a specific gravity of 1.42. Baumrucker (1) determined urine specific gravities in a series of patients just before and at a fifteen-minute collection after the intravenous injection of Diodrast. In this group urine containing the contrast medium showed an increase in specific gravity ranging from 0.007 to 0.042. Hence, during the course of intravenous urography the specific gravity of the urine varies, depending on its content of the opaque agent. In the absence of mixing, layering of the heavier, opacified urine below the less opacified or non-opacified urine occurs. The upper pole of each kidney is more posteriorly placed than the lower; thus, the superior calyces, being more dependent than the inferior calyces in the supine position, will be more readily opacified by the heavier contrast-containing urine in this position; conversely, in the prone position, the lower group of calyces are more dependent and should be better opacified. Similarly, inasmuch as the ureter cephalad to the pelvic brim lies in a plane anterior to the renal pelvis because of the normal lumbar lordosis, the prone position might afford better visualization of the ureters during intravenous urography. The layering of urine during intravenous urography has been the subject of previous reports. Fey and Truchot (3) in 1936 observed a patient with marked unilateral hydronephrosis due to an aberrant vessel, in whom the erect film demonstrated layering in the dilated calyces. In the discussion of this case, it was suggested that the layering was due to the different specific gravities of the contrast-laden urine and the non-opacified urine. Fey, however, had seen the layering persist for over an hour and he concluded that diffusion would by then have caused complete mixing had the effect been due only to a difference in specific gravity.