Intermittent Occlusion Research Articles

On-Off Malfunctıon In A Pedıatrıc Shunt: A Case Report

3 years-old-boy with a history of ventriculo-peritoneal shunt placement was admitted to our neurosurgery department with headache, vomiting and sunset eye phenomena. Direct X-ray examination of the shunt system was completely normal. The palpation of the shunt dome resulted the unfilling of pumping device. Computerised tomography (CT) of the head revealed ventricular enlargement and periventricular oedema. The patient was hospitalised for shunt revision. The symptoms were spontaneously disappeared within 48 hours. The pumping device returned to normal refilling. Follow up CT showed small ventricular size and shape. This case indicates that the symptomatic intermittent occlusion of the proximal shunt catheter can be seen in the paediatric age group and the obstruction may continue for a certain period and spontaneously return to normal function with correlated clinical response.

Mechanism of Coronary Malperfusion Due to Type-A Aortic Dissection

A 44-year-old man was admitted to a community hospital with acute onset of chest pain. Based on ECG findings and a mild troponin elevation, the patient was initially treated for acute coronary syndrome. On the 2nd day of hospitalization, troponin increased to 12 ng/ml and transthoracic echocardiography showed severe aortic regurgitation, so that computed tomography was performed and revealed Stanford type-A aortic dissection of the ascending aorta. The patient was immediately transferred to the hybrid operating room of our hospital. Preoperative coronary angiography showed nonstenotic coronary heart disease. Intraoperative transesophageal echocardiography revealed an intimal flap beginning just above the aortic valve. During diastole, the intimal flap prolapsed through the aortic valve, resulting in intermittent diastolic occlusion of the coronary ostia (Figure 1). Emergency operation resulted in successful replacement of the ascending aorta and reconstruction of the aortic valve. The postoperative course was uneventful. Aortic dissection coexisting with coronary malperfusion is a relatively rare [1, 2] but fatal condition. Even in the absence of obstructive coronary artery disease, these patients can suffer from significant impairment of myocardial perfusion due to diastolic collapse of the true lumen and occlusion of the coronary ostia by the dissection membrane. Ultimately, symptoms can mimic acute myocardial infarction to the point that thrombolytic treatment may be initiated inappropriately.

Intermittent occlusion enhances the smoothnessof sampled motion

Discrete sequences of sampled motion often appear flickering and jerky. We present evidence showing that a target in sampled motion is perceived as smoother when structure in the background appears and disappears synchronously with the target. Specifically, we found that target flicker is turned into permanent target visibility at short interstimulus intervals and jerkiness is replaced by smoothly accelerating and decelerating motion at longer ones. We argue that this "smoothening" effect is essentially a form of amodal completion in space-time being evoked by spatiotemporal cues to occlusion. The effect highlights the importance of amodal representations in perception.

Comparison of a large and small-calibre tube drain for managing spontaneous pneumothoraces

To compare treatment success of large- and small-bore chest drains in the treatment of spontaneous pneumothoraces the case-notes were reviewed of those admitted to our hospital with a total of 73 pneumothoraces and who were treated by trainee doctors of varying experience. Both a large- and a small-bore intercostal tube drain system were in use during the two-year period reviewed. Similar pneumothorax profile and numbers treated with both drains were recorded, resulting in a similar drain time and numbers of successful and failed re-expansion of pneumothoraces. Successful pneumothorax resolution was the same for both drain types and the negligible tube drain complications observed with the small-bore drain reflected previously reported experiences. However the large-bore drain was associated with a high complication rate (32%) with more infectious complications (24%). The small-bore drain was prone to displacement (21%). There was generally no evidence of an increased failure and morbidity, reflecting poorer expertise, in the non-specialist trainees managing the pneumothoraces. A practical finding however was that in those large pneumothoraces where re-expansion failed, the tip of the drain had not been sited at the apex of the pleural cavity irrespective of the drain type inserted.

Rapid assessment of rest myocardial ischaemia in the Chest Pain Unit

A 76-year-old man with a history of coronary bypass graft surgery presented to the Chest Pain Unit with chest discomfort. He underwent myocardial perfusion imaging (MPI) with 99m Tc-sestamibi. Immediately after acquisition of the rest scan he developed a new chest pain episode and received an additional tracer injection. The new images showed hypoperfusion in the inferior and inferolateral walls that were not observed in the previous rest scan images (a arrows). A coronary angiogram revealed subtotal proximal occlusion of a saphenous vein graft to the right coronary artery (b arrow) which was submitted to successful stent implantation. Acute coronary syndrome results from the combination of intermittent thrombotic occlusion and vasoconstriction resulting in markedly decreased regional myocardial perfusion [1]. Abnormal rest MPI in patients with acute chest pain is highly associated with acute myocardial infarction or the need for subsequent coronary revascularization [2]. These images demonstrate the exquisite sensitivity of MPI to changes in rest myocardial perfusion over a short period.

Cardiovascular Complications of Obstructive Sleep Apnea Syndrome: Evidence from Children

Obstructive Sleep Apnea Syndrome (OSAS) is a common condition in children, and is characterized by intermittent partial or complete occlusion of the upper airway during sleep, leading to profound disturbances in homeostatic gas exchange, frequent arousals and disturbed sleep architecture. Pediatric OSAS is associated with a multitude of end-organ morbidities, most of which have been uncovered in the last decade. Of particular interest are the cardiovascular complications that may develop in children with OSAS, since they are posited to have not only an immediately significant impact on cardiovascular health during childhood, but may also affect cardiovascular outcomes later during adult life. In this review, we will present the specific cardiovascular complications that have thus far been described in children with OSAS, with reference to pertinent mechanisms, and potential implications.

Evidence for Visual Compromise in Preverbal Children with Orbital Vascular Birthmarks

To learn whether electrophysiological changes indicating amblyopia occur even in the absence of clinically recognizable amblyopia. Prospective study. Four consecutive infants between 7 and 19 months of age with unilateral periocular vascular lesions that intermittently obstructed vision in the affected eye and no clinical evidence of amblyopia were evaluated. No child had anisometropia greater than 0.50 diopter in the greatest meridian or strabismus. Sweep visual evoked potential vernier acuity was measured under monocular viewing conditions with the fellow eye tested as the control. Response amplitudes and acuity thresholds were significantly diminished in the affected eyes. A phase analysis showed slowing of the response in the affected eyes compared with the control eyes. An amblyopia-like effect on vernier acuity occurred in infants with unilateral periocular vascular birthmarks when the lesion caused intermittent occlusion of the eye. Whether long-term effects will occur is unknown, but children with no clinically apparent amblyopia in the setting of a vascular mark or other cause of intermittent occlusion of the visual axis should be followed, since these electrophysiology findings suggest amblyopia may be present.

Laparoscopic Left Lateral Sectionectomy: Surgical Technique and Our Results from Leeds

Although laparoscopic left lateral sectionectomy is increasingly becoming the accepted approach for resection of tumors in hepatic segments II and III, the variations in surgical technique exist. Our technique relies on mobilization of the left lateral sector followed by extracorporeal control of the portal pedicle allowing intermittent occlusion when needed. The parenchyma is thinned, exposing the inflow and outflow allowing application of endoscopic staplers under direct vision for parenchymal transection. Eleven patients underwent left lateral sectionectomy between 2000 and November 2007 and had a median postoperative stay of 3 days. Two patients had to be converted early on. Left lateral sectionectomy using this approach appears to be safe and reproducible, and this technique should be considered for patients with tumors in hepatic segments II and III.

Methods of vascular occlusion for elective liver resections

Vascular occlusion is used to reduce blood loss during liver resection surgery. There is considerable controversy regarding whether vascular occlusion should be used or not during elective liver resections. The method of vascular occlusion employed is also controversial. There is also considerable debate on the role of ischaemic preconditioning before vascular occlusion. To assess the advantages (decreased blood loss and peri-operative morbidity) and disadvantages (liver dysfunction from ischaemia) of vascular occlusion during liver resections. To compare the advantages (in decreasing blood loss or decreasing ischaemia-reperfusion injury) and disadvantages of different types of vascular occlusion versus total, continuous portal triad clamping. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until March 2007. We included randomised clinical trials comparing vascular occlusion versus no vascular occlusion during elective liver resections (irrespective of language or publication status). We also included randomised clinical trials comparing the different methods of vascular occlusion and those investigating the role of ischaemic preconditioning in liver resection. We collected the data on the characteristics of the trial, methodological quality of the trials, mortality, morbidity, blood loss, blood transfusion requirements, liver function tests, markers of neutrophil activation, operating time, and hospital stay. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each binary outcome we calculated the odds ratio (OR) with 95% confidence intervals (CI) based on intention-to-treat analysis. For continuous outcomes, we calculated the weighted mean difference (WMD) with 95% confidence intervals. We identified a total of 16 randomised trials. Five trials including 331 patients compared vascular occlusion (n = 166) versus no vascular occlusion (n = 165). Six trials including 521 patients compared different methods of vascular occlusion. Three trials including 210 patients compared ischaemic preconditioning before continuous portal triad clamping (n = 105) versus no ischaemic preconditioning (n = 105). Two trials including 127 patients compared ischaemic preconditioning before continuous portal triad clamping (n = 63) versus intermittent portal triad clamping (n = 64).The blood loss was significantly lower in vascular occlusion compared with no vascular occlusion. The liver enzymes were significantly elevated in the vascular occlusion group compared with no vascular occlusion. There was no difference in the mortality, liver failure, or other morbidities. Four of the five trials comparing vascular occlusion and no vascular occlusion used intermittent vascular occlusion. Trials comparing complete inflow and outflow occlusion to the liver, ie, hepatic vascular exclusion and portal triad clamping demonstrate significant detrimental haemodynamic changes in hepatic vascular exclusion compared to portal triad clamping. There was no significant difference in the number of units transfused and the number of patients needing transfusion. There was no difference in mortality, liver failure, or morbidity between total and selective methods of portal triad clamping. All four cases of mortality and liver failure in the comparison between the intermittent and continuous portal triad clamping occurred in the continuous portal triad clamping (statistically not significant). Intermittent portal triad clamping does not increase the total blood loss or operating time compared to continuous portal triad clamping.There was no statistically significant difference in the mortality, liver failure, morbidity, blood loss, or haemodynamic changes between ischaemic preconditioning versus no ischaemic preconditioning before continuous portal triad clamping. Liver enzymes used as markers of liver injury were significantly lower in the early post-operative period in the ischaemic preconditioning group. The intensive therapy unit stay and hospital stay were statistically significantly lower in the ischaemic preconditioning group than in the no ischaemic preconditioning group.There was no statistically significant difference in the mortality, liver failure, morbidity, intensive therapy unit stay, or hospital stay between ischaemic preconditioning before continuous portal triad clamping and intermittent portal triad clamping. The blood loss and transfusion requirements were lower in the ischaemic preconditioning group. Aspartate aminotransferase level was lower in the intermittent portal triad clamping group than the ischaemic preconditioning group on the third post-operative day. There was no difference in the peak aspartate aminotransferase levels or in the aspartate aminotransferase levels on first or sixth post-operative days of aspartate aminotransferase . Intermittent vascular occlusion seems safe in liver resection. However, it does not seem to decrease morbidity. Among the different methods of vascular occlusion, intermittent portal triad clamping has most evidence to support the clinical application. Hepatic vascular exclusion cannot be recommended routinely. Ischaemic preconditioning before continuous portal triad clamping may be of clinical benefit in reducing intensive therapy unit and hospital stay.

Methods of vascular occlusion for elective liver resections

Vascular occlusion is used to reduce blood loss during liver resection surgery. Various methods of vascular occlusion have been suggested. To compare the benefits and harms of different methods of vascular occlusion during elective liver resection. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008. We included randomised clinical trials comparing different methods of vascular occlusion during elective liver resections (irrespective of language or publication status). Two authors independently assessed trials for inclusion and independently extracted the data. We calculated the risk ratio or mean difference with 95% confidence intervals using fixed-effect and random-effects models based on intention-to-treat or available data analysis. Ten trials including 657 patients compared different methods of vascular occlusion. All trials were of high risk of bias. Only one or two trials were included under each comparison. There was no statistically significant differences in mortality, liver failure, or other morbidity between any of the comparisons.Hepatic vascular occlusion does not decrease the blood transfusion requirements. It decreases the cardiac output and increases the systemic vascular resistance. In the comparison between continuous portal triad clamping and intermittent portal triad clamping, four of the five liver failures occurred in patients with chronic liver diseases undergoing the liver resections using continuous portal triad clamping. In the comparison between selective inflow occlusion and portal triad clamping, all four patients with liver failure occurred in the selective inflow occlusion group. There was no difference in any of the other important outcomes in any of the comparisons. In elective liver resection, hepatic vascular occlusion cannot be recommended over portal triad clamping. Intermittent portal triad clamping seems to be better than continuous portal triad clamping at least in patients with chronic liver disease. There is no evidence to support selective inflow occlusion over portal triad clamping. The optimal method of intermittent portal triad clamping is not clear. There is no evidence for any difference between the ischaemic preconditioning followed by vascular occlusion and intermittent vascular occlusion for liver resection in patients with non-cirrhotic livers. Further randomised trials of low risk of bias are needed to determine the optimal technique of vascular occlusion.

Vascular occlusion for elective liver resections

Vascular occlusion is used to reduce blood loss during liver resection. There is considerable controversy regarding whether vascular occlusion should be used or not during elective liver resections. To assess the advantages (decreased blood loss and peri-operative morbidity) and disadvantages (ischaemia-reperfusion injury related complications like liver dysfunction) of vascular occlusion during elective liver resections. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008. We included randomised clinical trials comparing vascular occlusion versus no vascular occlusion during elective liver resections (irrespective of language or publication status). Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. We calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat or available case analysis. We identified a total of five trials (of high bias-risk) which compared vascular occlusion (n = 166) versus no vascular occlusion (n = 165). Three of the five trials comparing vascular occlusion and no vascular occlusion used intermittent vascular occlusion. There was no difference in mortality, liver failure, or other morbidities. The blood loss was significantly lower in vascular occlusion compared with no vascular occlusion. The liver enzymes were significantly elevated in the vascular occlusion group compared with no vascular occlusion. Intermittent vascular occlusion seems safe in liver resection. However, it does not seem to decrease morbidity. More randomised trials seem to be needed.

Surgery for malignant liver tumors

Recent decades have witnessed an increase in liver resections. There is a need for an update on factors related to the management of liver tumors in view of newer published data. A systematic search using Medline, Embase, and Cochrane Central Register of Controlled Trials for the years 1983-2008 was performed. The IHPBA classification provides a suitable nomenclature of liver resections. While one randomized trial has provided an objective time of 30 min as optimal for intermittent pedicle occlusion, another randomized study has demonstrated the feasibility of performing liver resections without pedicle clamping. A randomized trial has demonstrated the benefit of clamp crushing over newer techniques of liver transection. Cohort studies support anatomical resections when feasible in terms of outcomes. Nonrandomized studies also support nonanatomical and ablative therapies in patients with cirrhosis and small remnant livers. A randomized trial has shown comparable long-term outcomes of radiofrequency ablation (RFA) and surgery for tumors < 5 cm. No randomized trials comparing laparoscopy and open surgery exist. Surgery remains an important treatment modality for malignant hepatic neoplasms. While anatomical resections provide improved survival, the choice of nonanatomical versus anatomical resections should be individualized taking into account factors such as cirrhosis and function of the liver remnant. A clear margin of resection is essential in all surgically resected cases. RFA is emerging as a useful, often complimentary tool, to surgery when dealing with complex tumors or tumors in patients with a poor liver function. Laparoscopic ultrasonography is useful in staging and performance of RFA.

Early and Late Cardiac Perforation by Amplatzer ASD and PFO Devices

Cardiac perforation and device erosion is an infrequent but potentially lethal complication of percutaneous occluder device insertion. Transthoracic and transesophageal echocardiography (TEE) and gated cardiac CT are useful in detecting this complication.Wepresent characteristic clinical and imaging findings of early and late cardiac perforation diagnosed at our institution, prior to surgical correction. Results: Echocardiograms from 230 device insertions were retrospectively reviewed. 2 cases of confirmeddevice erosion were identified, occurring from 2 weeks to 18 months after device insertion. Clinical and imaging features of device erosion were: (a) new cardiac symptoms of pericardial pain, dyspnoea or tamponade, (b) device size and geometry in relation to atrial size, particularly device extending >90% across the atrial septum, (c) relationship of device to aorta and posterior atrial wall, (d) deficient superior-anterior rim, (e) presence of pericardial fluid adjacent to device, (f) TEE or CT evidence of disc protrusion into or through the atrial/aortic wall. Discussion: Device erosion can be gradual and present with progressive symptoms of pericardial chest pain and/or dyspnoea in the early or late stages post percutaneous ASD or PFO closure. Cardiac perforation by the closure device can cause intermittent symptoms and pericardial fluid accumulation, due to intermittent occlusion of the puncture site by the device itself. Conclusion: Deficient superior-anterior rim and encroachment of the occluder device on the posterior atrial wall are important and under-recognised risk factors for device erosion. TEE should be performed prior to device insertion with heightened awareness of atrial geometry andmanufacturer’s guidelines for device sizing. This may reduce occurrence of this serious complication. TEE and cardiac CT are useful in confirming device erosion when present.

BDNF and TrkB in the Preterm and Near-term Ovine Fetal Brain and the Effect of Intermittent Umbilical Cord Occlusion

We have determined the developmental change in immunoreactivity for brain-derived neurotrophic factor and its high-affinity tyrosine kinase receptor, TrkB, in the ovine fetal brain with advancing gestation and in response to intermittent umbilical cord occlusion, which might then contribute to adverse neurodevelopment. Fetal sheep (control and experimental groups at 0.75 and 0.90 of gestation) were studied over 4 days with umbilical cord occlusions performed in the experimental group animals by complete inflation of an occluder cuff for 90 seconds every 30 minutes for 3 to 5 hours each day. Animals were then euthanized and the fetal brains perfusion fixed and prepared for subsequent histology with the distribution of brain-derived neurotrophic factor and tyrosine kinase receptor immunoreactivity determined by immunohistochemistry. In the control group animals brain-derived neurotrophic factor immunoreactivity decreased in the gray matter, thalamus, and hippocampus but increased in the white matter, while tyrosine kinase receptor immunoreactivity decreased in all regions (most P < .01), with advancing gestation consistent with the developmental change from neurogenesis/gliagenesis to myelination over this time period. Intermittent umbilical cord occlusion as studied with severe but limited hypoxemia resulted in a variable decrease in brain-derived neurotrophic factor and tyrosine kinase receptor immunoreactivity for all brain regions in the preterm animals (most P < .01) when protein turnover is higher, but a selective increase in brain-derived neurotrophic factor immunoreactivity in the hippocampus of the near-term animals consistent with a heightened vulnerability for necrotic/apoptotic injury at this time. As such, brain-derived neurotrophic factor-tyrosine kinase receptor in the ovine fetal brain may be altered with intermittent hypoxic insults over the latter part of pregnancy with potential for longer term neurologic consequences.

C2 spinal cord stimulation induces dynorphin release from rat T4 spinal cord: potential modulation of myocardial ischemia-sensitive neurons

During myocardial ischemia, the cranial cervical spinal cord (C1-C2) modulates the central processing of the cardiac nociceptive signal. This study was done to determine 1) whether C2 SCS-induced release of an analgesic neuropeptide in the dorsal horn of the thoracic (T4) spinal cord; 2) if one of the sources of this analgesic peptide was cervical propriospinal neurons, and 3) if chemical inactivation of C2 neurons altered local T4 substance P (SP) release during concurrent C2 SCS and cardiac ischemia. Ischemia was induced by intermittent occlusion of the left anterior descending coronary artery (CoAO) in urethane-anesthetized Sprague-Dawley rats. Release of dynorphin A (1-13), (DYN) and SP was determined using antibody-coated microprobes inserted into T4. SCS alone induced DYN release from laminae I-V in T4, and this release was maintained during CoAO. C2 injection of the excitotoxin, ibotenic acid, prior to SCS, inhibited T4 DYN release during SCS and ischemia; it also reversed the inhibition of SP release from T4 dorsal laminae during C2 SCS and CoAO. Injection of the kappa-opioid antagonist, nor-binaltorphimine, into T4 also allowed an increased SP release during SCS and CoAO. CoAO increased the number of Fos-positive neurons in T4 dorsal horns but not in the intermediolateral columns (IML), while SCS (either alone or during CoAO) minimized this dorsal horn response to CoAO alone, while inducing T4 IML neuronal recruitment. These results suggest that activation of cervical propriospinal pathways induces DYN release in the thoracic spinal cord, thereby modulating nociceptive signals from the ischemic heart.

Ischemic preconditioning and intermittent clamping confer protection against ischemic injury in the cirrhotic mouse liver

Surgery on cirrhotic livers is fraught with complications, and many surgeons refrain from operating on patients with cirrhosis. Surgical procedures include temporal occlusion of blood flow resulting in ischemia. The mechanisms of protective strategies to prevent ischemic injury in patients with cirrhosis are not fully understood. The aim of this study was to evaluate how the cirrhotic liver tolerates an ischemic insult, whether mechanisms other than those observed in the normal liver are active, and whether intermittent clamping and preconditioning, which are known as safe surgical strategies in normal and steatotic livers, confer protection to the cirrhotic liver. We applied partial hepatic inflow occlusion to cirrhotic mice fed carbon tetrachloride according to different vascular occlusion protocols: intermittent clamping with 15 or 30 minute cycles of ischemia or ischemic preconditioning prior to 60 or 75 minutes of ischemia. Continuous ischemia (60 or 75 minutes) served as controls. The results showed that the cirrhotic liver was significantly more susceptible to 60 minutes of ischemia than the normal liver. Apoptosis was higher in the normal liver, whereas necrosis was a predominant feature in the cirrhotic liver. Both protocols of intermittent vascular occlusion and ischemic preconditioning dramatically prevented injury compared to continuous occlusion for 60 minutes. This protection was associated with reduced necrosis and apoptosis, and particularly reduced activation of the apoptotic pathway through mitochondria. In conclusion, this study extends the protective effects of ischemic preconditioning and intermittent clamping to the cirrhotic liver, highlighting a diminished apoptotic pathway with dramatic improvement in the development of necrosis.

Hepatectomy using traditional Péan clamp–crushing technique under intermittent Pringle maneuver

Background The clamp-crushing technique has been proved to be the most cost-efficient approach for hepatectomy. If the advantageous characteristics, such as lower blood loss and morbidity, could be utilized, this method could be ideal. Methods The records of 380 patients who underwent hepatectomy using the clamp-crushing technique with intermittent inflow occlusion between 2002 and 2006 were retrospectively reviewed. One hundred fifty patients underwent major hepatectomy, and 230 underwent minor hepatectomy. Results Thirteen (3.4%) patients received red cell transfusion, and 21 (5.5%) patients received fresh frozen plasma. According to Clavien's classification system, grade I complications occurred in 42 (11.1%), grade II in 32 (8.4%), grade III in 14 (3.7%), grade IV in 1 (0.3%), and grade V in 2 (0.5%) patients. Female sex, preoperative albumin-to-globulin ratio, and type of resection were independent factors predictive of blood loss. Conclusions The present patient series, who underwent traditional Péan clamp–crushing technique under intermittent Pringle maneuver, had a low risk of complications. This procedure is an acceptable technique for hepatic parenchymal transection.

The Salvaged Area at Risk in Reperfused Acute Myocardial Infarction as Visualized by Cardiovascular Magnetic Resonance

We aimed to characterize the tissue changes within the perfusion bed of infarct-related vessels in patients with acutely reperfused myocardial infarction (MI) using cardiovascular magnetic resonance (CMR). Even in successful early revascularization, intermittent coronary artery occlusion affects the entire perfusion bed, also referred to as the area at risk. The extent of the salvaged area at risk contains prognostic information and may serve as a therapeutic target. Cardiovascular magnetic resonance can visualize the area at risk; yet, clinical data have been lacking. We studied 92 patients with acute MI and successful reperfusion 3 +/- 3 days after the event and 18 healthy control subjects. Breath-hold T2-weighted and contrast-enhanced ("late enhancement") CMR were used to visualize the reversible and the irreversible myocardial injury, respectively. All reperfused infarcts consistently revealed a pattern with both reversibly and irreversibly injured tissue. In contrast to the infarcted area, reversible damage was always transmural, exceeding the infarct in its maximal extent by 16 +/- 11% (absolute difference of the area of maximal infarct expansion 38 +/- 15% vs. 22 +/- 10%; p < 0.0001). None of the controls had significant T2 signal intensity abnormalities. In patients with reperfused MI, CMR visualizes both reversible and irreversible injury. This allows for quantifying the extent of the salvaged area after revascularization as an important parameter for clinical decision-making and research.

William E. Bradley and His Contributions to Urology

We review the myriad contributions to urological science by neurologist and engineer, William E. Bradley. Remembrances and personal interviews were collated for this article. Doctor Bradley was a pioneer in neurourology. He described a neurophysiological paradigm for micturition, devised urodynamic and electrophysiological techniques, and contributed to the development of genitourinary prosthetic devices. Doctor Bradley made notable and groundbreaking contributions to urology, many of which are still in use today.

Localized pulmonary interstitial emphysema: treatment by bronchial occlusion.

Selective bronchial occlusion for the treatment of localized cystic pulmonary interstitial emphysema (PIE) offers a means to facilitate weaning from ventilatory support and to preserve potentially functional lung parenchyma. We employed a commercially manufactured balloon catheter, placed under direct visualization to occlude a left mainstem bronchus in two cases of localized PIE. This is the safest method for selective bronchial occlusion so far reported. Therapeutic success was achieved with either continuous or intermittent bronchial occlusion. Evaluation of pulmonary function with nuclear scintigraphy aids in determining the most appropriate position for the occluding catheter and permits assessment of the resultant improvements in pulmonary function.