Bilateral subcapsular and perinephric hemorrhage as the initial presentation of polyarteritis nodosa

Polyarteritis nodosa is a systemic vasculitis of medium and small-sized arteries associated with aneurysm formation. Aneurysms may be complicated by thrombosis, rupture and hemorrhage. Kidney involvement in polyarteritis nodosa can rarely be complicated by Wunderlich syndrome which is characterized by acute onset of spontaneous, nontraumatic subcapsular and perirenal hematomas. A 22-year-old woman with mental retardation due to childhood cytomegalovirus infection presented with flank pain, weight loss and fever, and was found to have bilateral subcapsular and perinephric hematomas. Spontaneous bilateral renal hemorrhage as the initial manifestation of polyarteritis nodosa is rare, and it can be associated with delays in diagnosis and treatment.

Current treatment and outcomes of perinephric abscesses

PURPOSE

We characterize the treatment and outcomes of perinephric abscesses in a contemporary cohort of patients.

MATERIALS AND METHODS

We reviewed the experience with perinephric abscesses at a single community based hospital. Abdominal computerized tomography (CT) was widely available during the study period and experience with radiographic guided percutaneous drainage was extensive. Therapy and intervention for individual patients were dictated by the treating physician.

RESULTS

Of the 25 patients identified with perinephric abscesses 3 (12%) ultimately died. Although 40% had multiple risk factors for perinephric abscesses only 35% were identified at presentation. Urine cultures were positive in 72% of patients and CT had a diagnostic sensitivity of 92%. Ten patients with a mean abscess size of 1.8 cm. were treated with antibiotics alone (mean hospitalization 10 days) while 11 with a mean abscess size of 11 cm. received antibiotics and initial percutaneous drainage (mean hospitalization 30 days). Of the 11 patients treated with percutaneous drainage 4 ultimately required surgical exploration and nephrectomy.

CONCLUSIONS

The clinical characteristics of perinephric abscesses have not changed significantly but improved imaging with CT allows earlier diagnosis and treatment, which likely contributed to the reduced mortality in our cohort compared to historical series. With accurate staging and careful followup, a variety of treatments can be successful, including antibiotics alone or in conjunction with percutaneous drainage and urinary drainage. Open surgical drainage and nephrectomy may eventually be required in some patients and should be considered if adequate drainage is not achieved.

[Imaging of acute urinary infections in adults. Radiologic findings and strategy for imaging procedures]

Urinary infection is very common in women. Generally no imaging is needed. The role of imaging is mandatory in the following cases: renal infection, urinary obstructive syndrome, immuno-compromised patients. The results of imaging in pathology are described: pyelonephritis, renal and perinephric abscesses with or without phlegmon, perinephritis and emphysematous perinephritis. A strategy for imaging procedures is proposed.

Bilateral xanthogranulomatous perinephritis without renal parenchymal involvement

A case of isolated bilateral xanthogranulomatous perinephritis, which presented as a symmetrical irregular perirenal rim of soft tissue, is reported. Differential diagnosis and image features on ultrasound, computed tomography, and magnetic resonance are discussed.

[Percutaneous drainage of renal and perirenal abscesses. 2 case reports]

Undetected and untreated renal and perinephritic abcesses are associated with high morbidity and mortality rates. Thanks to the technique of ultrasonography and computed tomography, it is now possible to identify a suspected abscess early on. As treatment, percutaneous drainage has proved both effective and associated with only few side effects. Two cases are reported, one with renal, one with perinephritic abscess, both of which were successfully treated with percutaneous drainage.

[The association of pleural empyema and perinephritic infection: apropos 4 cases]

Empyema of renal origin is very rare (3% in our series). We discuss 4 cases of empyemas associated to perirenal infection. Two of them were diabetic and all of them have renal lithiasis. They made their debut through pleural effusions, isolating Escherichia coli in all of them. Treatment was antibiotics and drainage in both foci, three of them evolved to healing and one of them died being the abdominal foci without drainage. This association must be suspected when no clear etiology of the empyema is present in patients with history of renal lithiasis and diabetes.

Evaluating consensus among physicians in medical knowledge base construction

This study evaluates inter-author variability in knowledge base construction. Seven board-certified internists independently profiled "acute perinephric abscess", using as reference material a set of 109 peer-reviewed articles. Each participant created a list of findings associated with the disease, estimated the predictive value and sensitivity of each finding, and assessed the pertinence of each article for making each judgment. Agreement in finding selection was significantly different from chance: seven, six, and five participants selected the same finding 78.6, 9.8, and 1.6 times more often than predicted by chance. Findings with the highest sensitivity were most likely to be included by all participants. The selection of supporting evidence from the medical literature was significantly related to each physician's agreement with the majority. The study shows that, with appropriate guidance, physicians can reproducibly extract information from the medical literature, and thus established a foundation for multi-author knowledge base construction.

[Perinephritic abscess]

In spite of technical advances in diagnostic radiology the recognition of a perinephric abscess is still a challenge to even the most experienced urologist. Untreated perinephric abscesses result in considerable mortality. We present ten years experience from 17 patients. All underwent open drainage procedures. In our case this still seems to be the treatment of choice for the majority of these patients. Percutaneous drainage is an alternative to surgery, and is particularly suitable for the high risk patient.

[Perinephritic abscesses: a review of 50 cases (author's transl)]

Accumulation of pus in the perinephritic cavity often gives rise to doubtful clinical manifestations, which hinder and delay prompt diagnosis of this severe process. The clinical, biological, radiological and therapeutic characteristics of 50 cases are reviewed; all were confirmed by either surgery or necropsy. The most frequent clinical manifestations were fever, lumbar pain and signs of localized inflammation. Biological data showed ESR elevation and left shift of leukocytes as the most constant finding. Pyelograms were abnormal in 90% with blurring of the psoas and contour of the kidney the most frequent finding. Gram-negative organisms were frequently isolated, with staphylococci accounting for 10%. Only surgical treatment had a definite effect on evolution. The mortality rate was high, due to incorrect or delayed diagnosis.

[Value of ultrasonography in the diagnosis of renal abscesses. Results in 13 cases (author's transl)]

The results of ultrasonography recordings in 13 patients with renal abscesses are described: the image of the abscess is that of a cavity, of mixed structural composition, located inside the renal parenchyma. Ultrasonography has great diagnostic value, can be used to guide the aspiration needle and therapeutic procedures, and permits effective follow-up of the course of the disease. Chronic abscesses develop thick borders which give an ultrasonographic appearance similar to that of a necrotic cancer. In the perinephric phlegmon the cavity compresses the capsule. The pyonephrotic kidney is large and heterogenous in appearance. The clinical picture and the results of guided needle puncture are the essential features for diagnosis.

[Anterior perinephritic phlegmon (author's transl)]

A case is reported of an unsuspected anterior perinephritic phlegmon which had caused peritonitis of pyelonephritic origin thought to be due to a cholecystitis. The lesion was discovered during laparotomy and intravenous urography at operation demonstrated the condition of the underlying kidney and determined the therapeutic approach and the prognosis.

Gray scale nephrosonography: current status

Gray scale ultrasound evaluation of the kidney permits visualization of the texture of renal and hepatic parenchyma. This fact has led to more specific diagnoses in renal disease by non-invasive techniques. Current applications of gray scale ultrasound are presented. Ultrasound serves as a significant complementary technique to other modalities and is useful in some situations as a primary study.