Correspondence

Can chronic fatigue symptoms associated with nutcracker phenomenon be treated with aspirin?

To evaluate the clinical properties of patients with nutcracker syndrome (NCS).

The medical records of the patients with NCS were retrospectively investigated, and the patients' sex, age, presenting symptoms, urinalysis findings, associated diseases, and body mass indexes were recorded.

A total of 23 nonconsanguineous patients (11 male and 12 female patients, mean age 141 ± 36 months). Two patients had posterior NCS. Seventeen patients presented with 1 or >1 symptom. Fatigue and lassitude (n = 1), flank pain (n = 8), abdominal pain (n = 7), varicocele (n = 2), and macroscopic hematuria (n = 9) were the presenting symptoms. Only 6 patients had received a diagnosis of NCS from the urinalysis findings, which revealed microscopic hematuria or non-nephrotic proteinuria. The urinalysis findings disclosed isolated proteinuria in 6, hematuria plus proteinuria in 8, and macroscopic hematuria in 9 patients. Orthostatic proteinuria was detected in 7 patients. In patients with regressed hematuria and proteinuria, the body mass index was markedly increased at the end of the follow-up period relative to at diagnosis (at diagnosis 16.9 ± 4.0 kg/m²; at the end of the follow-up period 18.6 ± 4.6 kg/m²; P = .028).

The diagnosis of NCS should be considered in the presence of symptoms such as proteinuria and hematuria and should be absolutely ruled out before attempting renal biopsy. An apparent correlation between an increased body mass index and regression of symptoms was seen.

Nutcracker phenomenon refers to compression of the left renal vein, most commonly between the aorta and the superior mesenteric artery, with impaired blood outflow often accompanied by distention of the distal portion of the vein. The nutcracker syndrome (NCS) is the clinical equivalent of nutcracker phenomenon characterized by a complex of symptoms with substantial variations. Depending on specific manifestations, NCS may be encountered by different medical specialists. Although it may be associated with substantial morbidity, the diagnosis of NCS is often difficult and is commonly delayed. Diagnostic and treatment criteria are not well established, and the natural history of NCS is not well understood. We performed an initial review of the literature through MEDLINE, searching from 1950 to date and using the keywords nutcracker syndrome, nutcracker phenomenon, and renal vein entrapment. We performed additional reviews based on the literature citations of the identified articles. We attempted to elucidate clinical relevance of these conditions and their prominent features and to summarize professional experience.

Chronic Fatigue Syndrome is a physiological state in which the patient feels high levels of fatigue without an obvious organic cause, which affects around 1 in 400 people in the developed world. A wide range of causes have been suggested, including immune or hormonal dysfunction, viral or bacterial infection, and psychological somatization. It is likely that several causes are needed to trigger the disease, and that the triggers are different from the mechanisms that maintain fatigue over months or years. Many treatments have been tested for CFS, with very limited success – a programme of combined CBT and graded exercise shows the most effect. I suggest that patients with CFS have a reduced ability to increase mitochondrial energy production when exertion requires it, with fewer mitochondria that are each more efficient, and hence nearer to their maximum energy output, than normal. A range of indirect evidence suggests that the renin-angiotensin system stimulates mitochondrial responsiveness and reduces mitochondrial efficiency: chronic under-stimulation of this system could contribute to CFS aetiology. If correct, this means that CFS can be successfully treated with RAS agonists (eg angiotensin mimetics), or adrenergic agonists. It also suggests that there will be a positive link between the use of adrenergic- and RAS-blocking drugs and CFS incidence, and a negative link between adrenergic agonist use and CFS.