Large Pelvis Research Articles

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We believe that the dogmatic suggestion for removal of the associated enlarged pelvis during pyeloplasty just based on the microanatomy and elastin content studies is not accurate. 1 Starr N.T. Maizels M. Chou P. et al. Microanatomy and morphometry of the hydronephrotic “obstructed” renal pelvis in asymptomatic infants. J Urol. 1992; 148: 519-524 PubMed Google Scholar , 2 Kim D.S. Noh J.Y. Jeong H.J. et al. Elastin content of the renal pelvis and ureter determines post-pyeloplasty recovery. J Urol. 2005; 173: 962-966 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar Although the inefficient arrangement of muscle and collagen can make the radius and the wall of associated pelvis less elastic and can restrict the ureteral bolus, this is not applicable to a considerably dilated pelvis which can accommodate large volumes of urine. Besides, reduction of the pelvis will not enhance the urine transport capability because the contractility of remaining reduced pelvis with possible inefficient muscle arrangement will not spontaneously improve. What one should question is the potential fate of accumulated urine in the pelvis. It can be retained in the pelvis, delivered down the ureter, or escape by a pathophysiological mechanism. If the easiest access, the ureteropelvic junction, has been successfully reconstructed, reducing the pelvis will not be advantageous. Beneficial effect of reducing the pelvis is limited to the early postoperative period and not related with the drainage, which is only an accelerated improvement of ultrasound measurements. It is true in theory that removing the large pelvis can prevent kinking of the ureter; however, the potential risk of leakage and escalated fibrosis should be remembered. Editorial CommentUrologyVol. 76Issue 1PreviewThe authors present an interesting randomized study concerning the value of pelvic reduction during pyeloplasty. They found a significant decrease of the renal pelvis on ultrasound in the first and third month in patients with pelvic reduction vs patient without reduction. Six months after surgery, the difference was not significant anymore. Furthermore, the T½ time also improved in the reduction group, renal function did not demonstrate a difference. Removing a large renal pelvis during pyeloplasty is thought to reduce urinary stasis and to prevent the remaining large renal pelvis from kinking the ureter by folding over the new repair. Full-Text PDF

Duplex Kidney and Related Abnormalities

A 20-year-old woman felt right flank pain 2 years previously. At this time, she went to a local medical clinic where an abnormal urinary tract on the right side was found by imaging examinations. Surgical intervention was recommended, but she did not want to have surgery at that time. During those 2 years, intermittent right flank pain (three times per month) still bothered her. Therefore, she went to the outpatient department of our hospital. Sonogra phy of the kidney was carried out, revealing duplex bi lateral kidneys with hydronephrosis of the upper moiety of the right duplex kidney. Abdominal computed tomo graphy was then carried out, which revealed the following: (1) a right complete duplex kidney with an ectopic ureteral orifice and ureterocele, hydronephrosis and hydroureter of the upper moiety of the right complete duplex kidney; and (2) a left incomplete duplex kidney (Figure 1). Right retrograde pyelography (Figure 2) and cystography (Figure 3) were carried out, which confirmed the computed tomography findings of the abdomen. Two right ureteral orifices were found with cystoscopy: one was near the bladder neck, and the other associated with the uretero cele was over the trigone. Surgical intervention was recommended. She was admitted to our hospital for further management. Physical examination did not show any abnormalities. Laboratory examinations showed that all parameters were within normal limits. Surgical removal of the upper moiety and its ureter of the right complete duplex kidney was performed. The postoperative course was unremarkable. The patient was discharged in a stable condition, and outpatient department follow-up was recommended. A duplex (duplicated) kidney is a kidney that has two pyelocalyceal systems and is associated with a bifid ureter (incomplete duplication) or two ureters (double ureters) that empty separately into the bladder (complete duplication). A duplex kidney occurs in 12% of the population and may be unilateral or bilateral.1 Usually the lower moiety is dominant and drains most of the kidney, and a large renal pelvis drains the lower moiety via multiple calyces. The upper moiety may have only a single calyx and Accepted: April 13, 2010

In-vitro experimental assessment of a new robust algorithm for hip joint centre estimation

Hip joint centre (HJC) localization is used in several biomedical applications, such as movement analysis and computer-assisted orthopaedic surgery. The purpose of this study was to validate in vitro a new algorithm (MC-pivoting) for HJC computation and to compare its performances with the state-of-the-art (least square approach–LSA). The MC-pivoting algorithm iteratively searches for the 3D coordinates of the point belonging to the femoral bone that, during the circumduction of the femur around the hip joint (pivoting), runs the minimum length trajectory. The algorithm was initialized with a point distribution that can be considered close to a Monte Carlo simulation sampling all around the LSA estimate. The performances of the MC-pivoting algorithm, compared with LSA, were evaluated with tests on cadavers. Dynamic reference frames were applied on both the femur and the pelvis and were tracked by an optical localizer. Results proved the algorithm accuracy (1.7 mm±1.6, 2.3—median value±quartiles), reliability (smaller upper quartiles of the errors distribution with respect to LSA) and robustness (reduction of the errors also in case of large pelvis displacements).

Retrograde ureteroscopic holmium laser endopyelotomy in a selected population of patients with ureteropelvic junction obstruction

Significant controversy remains concerning the best way to treat ureteropelvic junction obstruction (UPJO). This study evaluates subjective and objective outcomes of retrograde holmium laser endopyelotomy in a selected population with UPJO. Forty-seven patients with UPJO were referred to retrograde endopyelotomy between April 2004 and March 2007. Patients with a very large pelvis, a high insertion of the ureter, a renal split function below 20% or a long (>2 cm) stenosed ureteropelvic segment, and patients younger than 18 years were not selected for endopyelotomy, but subjected to laparoscopic pyeloplasty. Renal function was estimated on renal diuretic scan before and after surgery with a mean renographic follow-up of 35 weeks. Subjective results were based on questionnaires which were returned from 44 patients with primary (n=37) or secondary (n=7) obstruction (mean follow-up 110 weeks). Success criteria were defined as symptom relief and improved or preserved renal function. Twenty-nine patients (66%) experienced complete symptom resolution and 10 patients (23%) had significant symptom improvement (i.e. no need for pain-killing medication). Five patients (11%) had unchanged symptoms. No difference in postoperative renal function was observed between these three groups of patients. The differences between preoperative and postoperative renal function were non-significant in each group. No major complications were observed. Five patients (11%) were referred to retreatment owing to unchanged symptoms. Retrograde ureteroscopic endopyelotomy is a safe and effective treatment option in patients with primary and secondary UPJO when selected properly.

Embolie gazeuse iatrogène après utilisation de peroxyde d’hydrogène

We report a case of severe oxygen embolism after wound irrigation under pressure with hydrogen peroxide into a closed or partially closed cavity. The accident was observed during a surgical dressing of a large pelvis gangrene area, after a 250 ml injection of hydrogen peroxide. Suddenly occurred a decrease in PETCO(2) and SpO(2), and then heart arrhythmia. Symptomatic treatment initiated immediately restored SpO(2) and heart rhythm within a few minutes and the patient was then treated with hyperbaric oxygen therapy. The patient recovered without cardiac or neurologic sequelae. The release of gaseous oxygen under the effect of tissue catalase and the vascular diffusion of this oxygen bubbles can explain such complication. Injection of large volume of hydrogen peroxide into a closed or partially closed cavity and/or under pressure injection must be prohibited.

Transperitoneal left laparoscopic pyeloplasty with transmesocolic access to the pelvi‐ureteric junction: technique description and results with a minimum follow‐up of 1 year

To describe and evaluate the safety and outcome of transperitoneal left laparoscopic pyeloplasty (TLLP) with a direct approach to the pelvi-ureteric junction (PUJ) through the mesentero-colic space, which avoids mobilization of the descending colon. From March 2005 to June 2006, 18 consecutive patients underwent TLLP with direct access. For each patient age, gender, body mass index (BMI), hospital stay, skin-to-skin operative time, time from incision of the posterior peritoneum to dissection of the PUJ, blood loss, time to resumption of oral intake and complications were recorded. Statistical analysis was used to assess whether the body habitus (BMI <25 kg/m(2) or >25 kg/m(2)) affected the outcomes. There were no complications during or after surgery and no conversions to open surgery were needed. The mean (SD) time to resumption of oral intake was 1.36 (0.5) days. The mean hospital stay was 3.3 (0.67) days and the mean follow-up was 17.4 (4.7) months. There was no statistical difference between patients with BMI higher or lower than 25 kg/m(2) (P = 0.42). The success rate at 1 year after surgery was 100%. TLLP with direct access to the PUJ through the mesentero-colic space is a safe and effective technique. This approach should be considered for all patients with left primary PUJ obstruction who are eligible for a LP and especially for slim patients or patients with a large renal pelvis.

TH‐D‐ValA‐05: Effect of Measured Cone‐Beam CT‐Density Calibration On Dose Calculations

Purpose: To characterize the CT‐density conversion for a cone‐beam CT (CBCT) system, and to evaluate the accuracy of dose calculation using CBCT images in head &amp; neck (H&amp;N) and abdominal sites. Method and Materials: A small (16 cm) and a large (32 cm) acrylic phantom with inserts of known electron densities were scanned on conventional CT and CBCT scanners. CBCT images were acquired using full and half fan (small phantom only), with and without bow‐tie filter. CT‐density conversion tables were measured for each combination. Head and pelvis phantoms, and H&amp;N and prostate patients were imaged. IMRT treatment plans were designed based on conventional CT and transferred to CBCT after image registration (deformable registration for H&amp;N patient). The CBCT dose distributions were then recalculated using the measured CT‐density curves. Results: For the small phantom, minimal differences were found between CT and CBCT numbers. Different conditions (half/full fan, with/without bow‐tie) resulted in maximum differences of approximately 100 HU. For the large phantom, differences between the CT numbers and CBCT numbers were greater than 350 HU at both low and high densities. For the H&amp;N patient and the head phantom, dose distributions calculated on CT and CBCT differed by less than 2%. For the pelvis phantom and prostate patient, there were substantial differences in the dose distributions. In the worst case, using CBCT images and the measured CBCT‐density conversion curve, the mean prostate dose was 14% higher than that calculated using the conventional CT. Due to artifacts in the CBCT, the differences in dose were larger using the CBCT‐density curves than using the default CT‐density curves. Using unit density for CBCT is a good approximation for pelvis dose calculation. Conclusion: Artifacts in CBCT images and CT‐density conversion may lead to considerable errors in dose calculation using the large pelvis CBCT images.

Steps to reduce operative time in laparoscopic dismembered pyeloplasty for moderate to large renal pelvis

Objectives To describe the steps to reduce the operative time for laparoscopic dismembered pyeloplasty in ureteropelvic junction obstruction with moderate to large hydronephrosis. Methods Using a transperitoneal approach and three ports, pyelotomy was done proximal to the ureteropelvic junction, and the ureter was spatulated laterally before dismembering it. Using the three suture line technique, the first suture was taken at the distal end of the spatulated ureter outside-in to the most dependent part of the pelvis inside-out and left as such. The second suture was taken at the proximal end of the ureter outside-in to the corresponding site at the posterior wall of the pelvis and then continued distally to complete the posterior suture line. A double- J stent was placed in an antegrade way. The anterior wall was completed with the first suture, taking continuous bites. The third suture line was used to close the pelvis. The operative time was recorded from placing the patient in the lateral position to the closure of the last port. Results From January 2002 to January 2004, 24 patients underwent pyeloplasty performed by a single surgeon. The mean pelvic volume was 80.4 cm 3 (range 70 to 110). The mean patient age was 24.5 years (range 5 to 57). The body mass index was 22.28 kg/m 2 (range 20 to 25). The mean operative time was 120.4 minutes (range 80 to 160). Minor complications were noted in 3 patients. All patients showed improvement in symptoms and drainage after a mean follow-up of 17 months (range 10 to 28). Conclusions These steps helped to reduce the operative time to close to that of open surgery, making laparoscopic pyeloplasty a more desirable alternative.

Big-bodied males help us recognize that females have big pelves

Schultz ([1949] Am. J. Phys. Anthropol. 7:401–424) presented a conundrum: among primates, sexual dimorphism of the pelvis is a developmental adjunct to dimorphism in other aspects of the body, albeit in the converse direction. Among species in which males are larger than females in body size, females are larger than males in some pelvic dimensions; species with little sexual dimorphism in nonpelvic size show little pelvic dimorphism. Obstetrical difficulty does not explain this relationship. The present study addresses this issue, evaluating the relationship between pelvic and femoral sexual dimorphism in 12 anthropoid species. The hypothesis is that species in which males are significantly larger than females in femoral size will have a higher incidence, magnitude, and variability of pelvic sexual dimorphism, with females having relatively larger pelves than males, compared with species monomorphic in femoral size. The results are consistent with the hypothesis. The proposed explanation is that the default pelvic anatomy in adulthood is that of the female; testosterone redirects growth from the default type to that of the male by differentially enhancing and repressing growth among the pelvic dimensions. Testosterone also influences sexual dimorphism of the femur. The magnitude of the pelvic response to testosterone is greater in species that are sexually dimorphic in the femur than in those that are monomorphic. Am J Phys Anthropol, 2005. © 2004 Wiley‐Liss, Inc.

Deep venous thrombosis: Comparison of indirect multidetector CT venography and sonography of lower extremities in 26 patients

Objective To compare the accuracy of indirect mutidetector row computed tomographic (MDCT) venography with lower extremity venous sonography for the diagnosis of femoropopliteal deep venous thrombosis (DVT), and to determine the frequency and location of DVT at MDCT venography. Materials and methods Twenty-six consecutive patients suspected of having pulmonary embolism (PE) underwent both combined MDCT venography and MDCT pulmonary angiography and lower extremity venous sonography. Indirect MDCT venography was acquired from the upper calves to the mid-abdomen following MDCT pulmonary angiography. The CT venographic findings were compared with those of sonography for the diagnosis of femoropopliteal DVT. All CT scans were also reviewed for the frequency and location of DVT. Results Indirect MDCT venography disclosed DVT in 19 patients, and 12 of whom also had PE. Seventeen patients with thrombosis in the femoropopliteal veins were identified in both indirect MDCT venography and sonography. The sensitivity and specificity of indirect MDCT venography for femoropopliteal DVT, as compared with sonography, were both 100%. In one patient DVT in the superficial femoral vein was detected using only indirect MDCT venography. MDCT venography also showed superior extension of femoropopliteal DVT to the inferior vena cava and iliac veins in four patients and thrombosis isolated to the inferior vena cava and common iliac vein thrombosis in one patient. Conclusions Indirect MDCT venography is as accurate as sonography in the diagnosis of femoropopliteal DVT. MDCT venography can further reveal thrombus in large pelvis veins and the inferior vena cava, an important advantage over sonographic screening for DVT.

PELVIC SEXUAL DIMORPHISM IN A METATHERIAN, DIDELPHIS VIRGINIANA: IMPLICATIONS FOR EUTHERIANS

Eutherians give birth to relatively large infants. Females have larger pelves than males, though males typically have larger nonpelvic bones. Pelvic dimorphism is an adaptation for parturition. Metatherian females, who give birth to markedly small infants, should not show pelvic adaptations for parturition and should have smaller pelves than males. Adult females and males of the Virginia opossum, Didelphis virginiana, are compared. Males are significantly larger than females in absolute size for 14 of 16 pelvic and 8 nonpelvic measures. Sexes did not differ significantly for lower iliac length and posterior space of midplane. However, relative lengths for females are significantly larger than for males for these 2 measures and for the pubis. These pelvic dimorphisms in opossums cannot be adaptations for parturition. These dimorphisms result from asynchrony among skeletal elements in growth cessation and sexual differences in adulthood growth.

LAPAROSCOPIC PYELOPLASTY: Indications, Technique, and Long-Term Outcome

Laparoscopic pyeloplasty is one of several minimally invasive treatment options for UPJ obstruction. In fact, several endoscopically and fluoroscopically controlled methods of incising the obstructed UPJ are now available that are significantly less invasive and less morbid in comparison with open pyeloplasty. However, the long-term success rates of these incisional techniques are less than the rates reported for open pyeloplasty. Several causes of obstruction may be present in the primarily obstructed UPJ, including kinking or compression related to crossing vessels or intrinsic narrowing at the UPJ. One potential reason for the inferior success rates of incisional methods in comparison with open pyeloplasty is that the former techniques address the intrinsically narrowed UPJ but may not address extrinsic problems such as kinking of the ureter associated with fibrotic bands or compression from crossing vessels. Laparoscopic pyeloplasty addresses all potential causes of obstruction. Any fibrotic bands kinking the ureter are divided, and the ureter is spatulated through the level of the UPJ prior to completion of the anastomosis. If a crossing vessel is encountered, a dismembered pyeloplasty is performed, the ureter and renal pelvis are transposed to the opposite side of the vessels, and the anastomosis is completed. An additional disadvantage of incisional techniques is the significant risk of hemorrhage following incision of the UPJ, with as many as 3% to 11% of patients requiring blood transfusion. Hemorrhage may occur owing to an errant anterior incision, the presence of a crossing vessel, incision into the renal parenchyma adjacent to the UPJ, or as the result of bleeding from the percutaneous access site. In contrast, mean estimated blood loss in the authors' series of 57 laparoscopic pyeloplasties was 139 mL, and none of the patients required blood transfusion. Although it is more morbid in comparison with retrograde or fluoroscopically controlled endopyelotomy, laparoscopic pyeloplasty seems at least comparable to antegrade percutaneous endopyelotomy in terms of the length of hospitalization and patient convalescence. Laparoscopic pyeloplasty, however, offers a higher success rate than with incisional techniques, not only from a radiographic standpoint but from a subjective standpoint as determined by the results of the analogue pain and activity questionnaire. The major disadvantage of laparoscopic pyeloplasty is the need for proficiency in laparoscopic techniques and for a longer operative time. As a result, the literature on laparoscopic pyeloplasty consists primarily of small series. Janetschek and co-workers reported on a series of 17 patients who underwent laparoscopic pyeloplasty, including 14 via a transperitoneal approach and 3 via a retroperitoneal approach. Procedures performed included ureterolysis alone, dismembered pyeloplasty, and nondismembered (Fenger) pyeloplasty. "Fenger-plasty" is similar to Y-V pyeloplasty and is performed by incising the UPJ longitudinally and closing the incision transversely in a Heineke-Mikulicz fashion. Janetschek and colleagues reported a 100% success in the eight patients who underwent dismembered pyeloplasty but believed that this technique was too cumbersome and should be reserved for patients with long stenoses, dorsally crossing vessels, or large renal pelvis. Because two of the four patients undergoing ureterolysis alone failed treatment, Janetschek and colleagues have abandoned this technique. They now prefer the Fenger-plasty technique, even in the setting of ventrally crossing vessels, because the technique can be performed quickly with one to three sutures, and the anastomosis can be sealed with fibrin glue and a flap of Gerota's fascia. Their experience with this technique, however, remains relatively limited. Technologic advances such as the Endostitch device have facilitated reconstructive laparoscopic procedures such as pyeloplasty. (ABSTRACT TRUNCATED)

Ecomorphological patterns of aerial feeding in oscines (Passeriformes: Passeri)

The hindlimb (myology and osteology) of swallows (Hirundinidae) is studied and compared with that of seven other passerine families to identify ecomorphological patterns. Muscular and osteological differences are found among swallow species and associations between morphology and foraging technique are examined. We explain morphological differences found in hirundinids as adaptations favouring flexion and adduction of the legs in these aerial foragers, which devote very little time to cursorial locomotion. This adaptive hypothesis is tested using a phylogenetic approach on the basis of an available molecular phylogenetic hypothesis. A clear ecomorphological pattern emerges relating foraging behaviour and pelvic morphology in hirundinids: aerial feeding technique is correlated with short distal leg segments, a large pelvis, a medial insertion of M. iliotibialis cranialis, an absence of pars accessoria of M. flexor cruris lateralis and a fused M. pubo-ischiofemoralis.

Ecomorphological patterns of aerial feeding in oscines (Passeriformes: Passeri)

The hindlimb (myology and osteology) of swallows (Hirundinidae) is studied and compared with that of seven other passerine families to identify ecomorphological patterns. Muscular and osteological differences are found among swallow species and associations between morphology and foraging technique are examined. We explain morphological differences found in hirundinids as adaptations favouring flexion and adduction of the legs in these aerial foragers, which devote very little time to cursorial locomotion. This adaptive hypothesis is tested using a phylogenetic approach on the basis of an available molecular phylogenetic hypothesis. A clear ecomorphological pattern emerges relating foraging behaviour and pelvic morphology in hirundinids: aerial feeding technique is correlated with short distal leg segments, a large pelvis, a medial insertion of M. iliotibialis cranialis, an absence of pars accessoria of M. flexor cruris lateralis and a fused M. pubo-ischiofemoralis.

The single compartment model applied to the large renal pelvis: a preliminary study

Diuresis renography should exclude or confirm pelvi-ureteric junction obstruction. Numerous equivocal cases seen here had large renal pelves with slow emptying on frusemide diuresis. An attempt was made to relate the rate of emptying to the volume of the renal pelvis. The fully distended renal pelvis during frusemide diuresis appears to satisfy the criteria of the single compartmental model which predicts a linear relationship between volume and flow rate, i.e. F = [0.693 V0]/t1/2 where F is the flow rate, V0 is the volume and t1/2 the time at which half the tracer has disappeared. Clearance half-time was measured from the diuresis renogram curve. Volume was estimated from a longitudinal ultrasound image at the end of the procedure, using a volumetric version of Simpson's rule as a sequential slice technique, given a roughly circular transverse image. Of 18 kidneys in 14 adult patients, three had large volume pelves and short emptying times. The remaining 15 showed a roughly linear relationship between volume as estimated and clearance half-time. This appears to validate both the theory and the method and permits calculation of the pelvic outflow rate. An hypothesis to explain the large unobstructed renal pelvis is advanced.

The single compartment model applied to the large renal pelvis: a preliminary study

Summary Diuresis renography should exclude or confirm pelvi-ureteric junction obstruction. Numerous equivocal cases seen here had large renal pelves with slow emptying on frusemide diuresis. An attempt was made to relate the rate of emptying to the volume of the renal pelvis. The fully distended renal pelvis during frusemide diuresis appears to satisfy the criteria of the single compartmental model which predicts a linear relationship between volume and flow rate, i.e. F = [0.693 V0]/t1/2 where F is the flow rate, V0 is the volume and t1/2 the time at which half the tracer has disappeared. Clearance half-time was measured from the diuresis renogram curve. Volume was estimated from a longitudinal ultrasound image at the end of the procedure, using a volumetric version of Simpson's rule as a sequential slice technique, given a roughly circular transverse image. Of 18 kidneys in 14 adult patients, three had large volume pelves and short emptying times. The remaining 15 showed a roughly linear relationship between volume as estimated and clearance half-time. This appears to validate both the theory and the method and permits calculation of the pelvic outflow rate. An hypothesis to explain the large unobstructed renal pelvis is advanced.

Errors of presentation

Errors of presentation during labor result in increased maternal and fetal morbidity and mortality and therefore deserve attention. For the purpose of this study, breech presentation is not included, and the errors discussed will include face, brow, compound, and shoulder presentations. When these problems are promptly diagnosed and properly managed, better results for mother and baby are obtained.A summary of the important etiological factors concerned in the study of the group includes such maternal factors as pelvic contraction, large pelvis, multiparity, lax abdominal wall, congenital anomalies of the uterus, placenta previa, and pelvic tumor. Fetal factors include prematurity, large infant, macerated fetus, multiple pregnancy, abnormality of the fetal neck, nuchal cord, and congenital anomalies. It is important to realize that upon diagnosing an error of presentation, possible etiological factors must immediately be investigated. Consideration of these factors may prevent errors in management and resultant tragedy.Early diagnosis is important since it determines management. Failure to make a prompt diagnosis of an error of presentation may predispose to uterine inertia which could result in prolonged labor with increased maternal and fetal morbidity. The usual means of diagnosis are abdominal, rectal, vaginal, and x-ray examinations. Despite careful abdominal examination during pregnancy, few errors except shoulder presentation are detected before labor starts.The most valuable diagnostic method is a careful vaginal examination in labor. It is frequently desirable to confirm a clinical diagnosis of an error of presentation radiologically, and, at the same time, to obtain additional information as to pelvic capacity, placental position, and possible fetal anomaly. However, abnormal presentation is often first diagnosed on x-ray in the presence of polyhydramnios or multiple pregnancy.The method of treatment depends on the type of error that is diagnosed, the etiological factor or factors involved, the condition of the mother and infant at the time the diagnosis is made, the experience of the operator, and the facilities at hand.

A Further Study in Normal Pyelograms and the Value of Bilateral Simultaneous Pyelography

AT the 1925 meeting of this Society we directed attention to the many variations in normal pyelograms. We divided those which we had observed into three groups: (a) ampullary; (b) bifid, and (c) a third to which we proposed applying the name “pseudospider,” because they resembled closely the “spider” deformity so often seen in pyelograms from cases of renal neoplasm. Since reading this paper we have had the opportunity to verify the convenience of retaining the above three groups. In to-day's contribution we add some unusual examples of the ampullary and bifid types. We referred briefly in our first paper to the value of bilateral ureteropyelography and described our technic. Since that time we have had abundant opportunity to see the many advantages and test the freedom from danger of such a method. We will refer to these matters later. As a third instructive experience during the past year we wish to call attention to the role which is played by contractions of the musculature of the renal pelvis and its calyces and of insufficient distention in the production of apparent deformities even in normal pyelograms. Let us now take these up in the order named. Additional Observations on the Three Previously Cited Groups of Normal Pyelograms 1. Ampullary type.—This is by far the most common of the three groups or types. One can find all degrees of variation, both in the size of the pelvis proper and in the size, mode of origin, etc., of the major calyces. There may be an almost rudimentary condition of the major calyces, as shown in Figure 1. There may be a difference between the pelves of the two sides, as shown in Figure 2, where one fails to see an inferior major calyx on the right side but can observe a relatively large pelvis proper and a very well developed wide-necked superior major calyx. On the opposite (left) side the pelvis proper and all of the calyces are extremely narrow. In Figure 3 we note the same type of pelvis on both sides, i.e., ampullary with very long major calyces, especially the superior. On the right side the pelvis proper is vertical while on the left side it is almost horizontal. 2. Bifid type.—We have encountered an unusual example of this group, as can be observed in Figure 4. The two chief divisions unite, close to the point of origin of the ureter. The upper pelvis has a well defined superior and a rudimentary inferior major calyx. The lower pelvis has both superior and inferior major calyces and also a rudimentary middle one arising from the superior. One can readily understand such a case by comparison with Figure 6 of our previous paper, in which the evolution of the bifid pelvis from the one with a long superior calyx can be seen.

PYURIA IN MALFORMATIONS OF THE URINARY TRACT

REVIEW OF LITERATURE In a series of cases of urinary infection in children, which were collected and reported,1a baby, aged 6 weeks, was observed who had persistent pyuria with continuous fever, and presented a tumor in the median line which could be palpated through the abdominal wall. On necropsy this tumor proved to be a horseshoe kidney. The large dilated pelvis contained a purulent secretion, and numerous miliary abscesses were found distributed through the kidney parenchyma. This was my first acquaintance with pyuria in malformations of the urinary tract. Since that time, a number of children with protracted pyuria have presented themselves, and malformation of the bladder, ureters or kidney could be demonstrated in some of them, frequently by cystoscopic examination, occasionally at necropsy. This etiologic factor as a cause of chronic pyuria has received scant attention in the pediatric literature. Gerstenberger and Wahl,2in discussing the

The Trendelenburgh position in Tumors of the Pelvis obstructing Labor

Dr. M. was invited by another doctor to the 1st woman in labor, whose pelvis was filled with a solid tumor, the size of the head of a full-term baby; the pharynx was felt above the pubis, and above the fetal head. The author got the idea to test the Trendelenburg position, that is, to force the tumor to descend into the large pelvis and lead the fetal head past the first.