Assessment of clinical renal preservation by phosphorus-31 magnetic resonance spectroscopy

To evaluate the role of magnetic resonance spectroscopy (MRS) and to develop surface coils for assessing cadaveric renal viability during hypothermic storage, we used the monophosphate/inorganic phosphate ratio (MP/Pi) to monitor phosphorous metabolites in intact kidneys during various renal preservation maneuvers. Eighteen canine kidneys and 16 cadaveric kidneys were studied as follows: Group 1 (N = 4) in situ kidneys were monitored by implanted MRS coils; Group 1 (N = 4) ex vivo kidneys were immediately attached to vascular cannulas and monitored by MRS surface coils during normothermic perfusion; Group 3 (N = 4) kidneys were removed, cold-flushed and, after 24 hours of 4C storage, monitored by MRS surface coils before and during four hours of reperfusion via vascular cannulas; Group 4 (N = 6) kidneys were removed, cold-flushed and monitored by surface coils during cold storage up to 72 hours. In addition, 16 cadaveric kidneys were studied while in sterile cold-storage containers. Postoperative renal function was followed in recipient patients. The MP/Pi ratios in Group 1 kidneys correlated with the ability to regenerate adenosine triphosphate (ATP). Groups 2 and 3 showed similar regeneration of ATP and MP/Pi after postischemic reperfusion, and the signal-to-noise ratios of the surface coils were better than those in the implanted coils in Group 1. Surface-coil monitoring in Group 4 kidneys showed predictable decay rates of MP/Pi during one to 72 hours of cold storage; in contrast, simultaneous cortical medullary microcirculation studies with 99mTc-macroaggregated albumin were inconclusive. Human cadaveric kidneys with high MP levels were associated with excellent renal function after transplantation, while those with low MP (less than or equal to 0.50) were associated with nonviability. We conclude that MRS is a practical and safe diagnostic modality for clinical transplantation.     

The prevalence of peripheral arterial disease and medial arterial calcification in patients with chronic renal failure: requirements for diagnostics

BACKGROUND: Knowledge of the prevalence of peripheral arterial disease (PAD) in patients with chronic renal failure (CRF) is limited because of a lack of uniformity in disease definition and recognition. Furthermore, little is known of the prevalence of medial arterial calcification (MAC) in patients with CRF. Our goal is to study the prevalence of PAD and MAC defined by ankle brachial index (ABI) or toe brachial index (TBI) measurements in a Finnish population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients. METHODS: We examined 136 patients with CRF and 59 control subjects. Fifty-nine of the patients with CRF had moderate to severe predialysis CRF, 36 patients were on dialysis treatment, and 41 were renal transplant recipients. Mean age of patients was 51.9 +/- 11.5 years, and 39 patients (29%) had diabetes. ABI and TBI were measured by means of photoplethysmography. The definition of PAD required an ABI value of 0.90 or less, a TBI value of 0.60 or less, or a previous positive lower-extremity angiogram result. ABI values of 1.3 or greater or incompressible arteries at ankle level indicated MAC. The presence of claudication was determined by an interview. RESULTS: Prevalences of PAD on this study were 22.0% in patients with predialysis CRF, 30.6% in patients on dialysis treatment, 14.6% in renal transplant recipients, and 1.7% in the control group (P = 0.001). Prevalences of MAC were 23.7%, 41.7%, 23.1%, and 3.4% (P < 0.001), respectively. Only 9 patients had claudication, and 6 of those patients had PAD. CONCLUSION: Both asymptomatic PAD and MAC are common in patients with CRF. Therefore, we recommend the use of both ABI and TBI measurements in the evaluation of PAD in patients with CRF.     

Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.