Emphysematous pyelonephritis successfully treated with laparoscopic nephrectomy

Emphysematous pyelonephritis is a severe life-threatening infection which continues to carry significant morbidity and mortality. We present a case recently managed at our institution by laparoscopic nephrectomy. The patient survived, and in comparison to some of the more conventionally managed patients in the literature, made an extremely speedy recovery. We would advocate this option to be seriously considered when patients are suitable and appropriately trained surgeons are available.     

Adult Retinofugal Axons Regenerating Through Peripheral Nerve Grafts Can Restore the Light-induced Pupilloconstriction Reflex

To investigate the ability of mature regenerating retinal axons to form functional connections within central targets, severed axons were guided into the primary visual centres which subserve the pupillary constriction reflex in response to light. The ocular stump of the transected optic nerve of adult rats was connected by means of an autologous peripheral nerve graft with the pretectal region which contains the relay nucleus of pupillary constriction, the olivary pretectal nucleus. This nucleus is efferently connected with preganglionic neurons in the oculomotor nuclear complex which innervates parasympathetically the muscle constrictors of the iris. Six to sixteen weeks after optic nerve transection and peripheral nerve transplantation, brisk responses were observed in the pupils upon illumination of the transplanted eye. Recovery of the pupil responses indicated that retinal neurons used the peripheral nerve 'bridge' to access the pretectum, in which they established synaptic contacts in sufficient density and with appropriate specificity to reconstitute the function of the traumatically interrupted neuronal circuitry.     

Long-term outcome of pneumatic dilation in the treatment of achalasia

OBJECTIVE: Achalasia is a well-defined esophageal motor disorder for which pneumatic dilation is an established therapeutic method. Even though it has been used for several years, there are limited data on the long-term outcomes of patients treated with this procedure. Hence, we aimed to evaluate the long-term efficacy of pneumatic dilation to control the symptoms of achalasia. METHODS: The medical records of all patients treated in our unit for achalasia with pneumatic dilation were reviewed. We identified the long-term result of the initial procedure, the date of the first dilation, and the time interval between dilation and retreatment. RESULTS: Of 260 patients who were treated with pneumatic dilation, 153 (67 men, 86 women) were followed up for more than 5 yr. The mean follow-up period was 11.09 +/- 3.91 yr, and the success rate of the dilation was 75.8%. Among these patients, 35 (19 men, 16 women) had follow-up periods of more than 15 yr. The mean follow-up time of those patients was 16.56 +/- 1.09 yr, and the success rate was 51.4%. Kaplan-Meier survival analysis showed that, overall, 50% of patients develop recurring symptoms after 10.92 yr. CONCLUSIONS: Although 51.4% of patients continued to be in clinical remission more than 15 yr after the initial pneumatic dilation, the long-term success rate of pneumatic dilation seems to drop progressively with time.     

Re-do aortic valve replacement: does a previous homograft influence the operative outcome?

BACKGROUND AND AIM OF THE STUDY: Late reoperation for failed aortic homograft is widely regarded as a high-risk procedure. A review is presented of the authors' experience of redo-aortic valve replacement (re-do AVR) examining factors which affect, and whether a previous aortic homograft replacement influences, operative outcome. METHODS: A retrospective review was conducted of consecutive re-do AVR performed at the authors' institution between 1998 and 2002. RESULTS: During the study period, 178 patients (125 males, 53 females; mean age 52.4 years; range: 16-85 years) underwent re-do AVR. The group included first-time (72%), second-time (20%), and more than third-time re-do AVR (8%). Forty-six patients (26%) received a homograft (group I), and 132 (74%) a stented biological/mechanical valve (group II). The two groups were matched for baseline clinical characteristics and operative variables. The type of explanted valve, and preoperative and operative variables, were analyzed using univariate and multivariate models. Primary outcome was defined as 30-day mortality, and secondary outcome as postoperative complications. The overall 30-day mortality was 12.3%, but was much lower (4.5%) for elective isolated and multiple re-do AVR. Univariate analysis showed significant predictors of 30-day mortality to be: age >65 years (p = 0.02); renal dysfunction (p = 0.005); preoperative unstable status (p = 0.03); preoperative NYHA class III/IV dyspnea (p = 0.02); non-elective operation (p = 0.01); preoperative arrhythmia (p = 0.005); history of chronic obstructive pulmonary disease (COPD) (p = 0.002); preoperative cardiogenic shock (p = 0.03); impaired left ventricular ejection fraction (LVEF) <50% (p = 0.04); and other valvular procedure(s) performed simultaneously (p = 0.01). In a multivariate analysis, the only significant predictors of 30-day mortality were impaired LVEF (p = 0.03) and a history of COPD (p = 0.007). Group I patients had a significantly shorter mean hospital stay (10.2+/-5.9 versus 14.1+/-12.5 days; p = 0.009), but there were no significant differences between groups in terms of postoperative complications. CONCLUSION: A previous aortic homograft replacement was not associated with an increased operative risk at the time of re-do AVR. A history was COPD was an important predictor of 30-day mortality, and this finding requires further investigation.     

Caffeine increases striatal dopamine D2/D3 receptor availability in the human brain

Caffeine, the most widely consumed psychoactive substance in the world, is used to promote wakefulness and enhance alertness. Like other wake-promoting drugs (stimulants and modafinil), caffeine enhances dopamine (DA) signaling in the brain, which it does predominantly by antagonizing adenosine A_2A receptors (A_2AR). However, it is unclear if caffeine, at the doses consumed by humans, increases DA release or whether it modulates the functions of postsynaptic DA receptors through its interaction with adenosine receptors, which modulate them. We used positron emission tomography and [¹¹C]raclopride (DA D₂/D₃ receptor radioligand sensitive to endogenous DA) to assess if caffeine increased DA release in striatum in 20 healthy controls. Caffeine (300 mg p.o.) significantly increased the availability of D₂/D₃ receptors in putamen and ventral striatum, but not in caudate, when compared with placebo. In addition, caffeine-induced increases in D₂/D₃ receptor availability in the ventral striatum were associated with caffeine-induced increases in alertness. Our findings indicate that in the human brain, caffeine, at doses typically consumed, increases the availability of DA D₂/D₃ receptors, which indicates that caffeine does not increase DA in the striatum for this would have decreased D₂/D₃ receptor availability. Instead, we interpret our findings to reflect an increase in D₂/D₃ receptor levels in striatum with caffeine (or changes in affinity). The association between increases in D₂/D₃ receptor availability in ventral striatum and alertness suggests that caffeine might enhance arousal, in part, by upregulating D₂/D₃ receptors.     

Aiming at One-Stage Corrective Surgery for Extended Thoracic Aortic Dilatation

Definitive treatment of extended thoracic aortic dilatation is a major surgical challenge. Histopathology of resected thoracic aortic wall may reveal undiagnosed aortitis affecting outcome. We sought to investigate the benefit of thorough histopathology after one-stage corrective surgery for the treatment of extended thoracic aortic dilatation. Five patients underwent one-stage corrective surgery using the hybrid open arch repair by the frozen elephant trunk together with endovascular aortic grafting. A representative sample of the resected aortic arch was procured for histology. T- and B-lymphocytes, plasma cells, macrophages, and immunoglobulin G4 (IgG4) positivity were evaluated by immunohistochemistry. The mean preoperative maximum aortic diameter was 54 mm (range, 41–79 mm). The mean follow-up was 18 months (range, 1–24 months). As confirmed by computed tomography (CT) upon follow-up, complete thrombosis of the false lumen at the level of the frozen elephant trunk was achieved in all patients with dissection. One patient was operated due to atherosclerotic dilatation of the thoracic aorta, and postoperative CT showed successful exclusion of the atherosclerotic dilatation; this 75-year-old man was diagnosed with IgG4-positive aortitis and experienced unexpected blindness after surgery without evidence of emboli or long-term neurological impairment upon repeated brain CT. The hybrid open arch repair by the frozen elephant trunk and simultaneous endovascular repair is a feasible choice for one-stage surgery through sternotomy aiming at definitive treatment of extended thoracic aortic pathology. However, systematic evaluation of inflammation may reveal concealed aortitis affecting postoperative outcome and need for long-term surveillance.