Sequential Balloon Research Articles

The Role of Bioresorbable Scaffolds in Meeting the Challenges of Bifurcations.

Side branches are frequently related to periprocedural complications. Considering any side branches >1 millimetres (mm), side branch occlusion or reduced flow may occur in approximately 10 % of interventional procedures. First data indicate that bioresorbable vascular scaffolds (BVS) behave similar compared with modern drug-eluting stents (DES) with regard to compromising or occluding sizeable side branches. Although technically more demanding compared with modern DES, it appears to be feasible to dilate side branches after crossing BVS cells. Preliminary data suggest at least balloon diameters up to 2.5 mm can be used, but safety remains unclear. Instead of kissing balloon dilatation, rather sequential balloon dilatation should be employed. Anecdotic evidence suggests BVS can be used even in relatively complex coronary anatomy, e.g. bifurcations distal to chronic total occlusion. Certainly more data are needed. As of today, BVS offer promise not only for the treatment of simple coronary lesions but also bifurcations. Given successful side branch protection, they might allow for restoring the native coronary anatomy in the sense of restitutio ad integrum.

Cateterismo intervencionista na estenose valvar pulmonar crítica do recém-nascido e na atresia pulmonar com septo interventricular íntegro: 13 anos de experiência de um serviço terciário

INTRODUCAO: A abordagem percutânea e opcao de escolha em neonatos portadores de estenose pulmonar critica (EP) e atresia pulmonar com septo interventricular integro (APSI). Neste trabalho sao descritos casos tratados consecutivamente em centro de referencia e seu seguimento a medio prazo. METODOS: A maioria dos pacientes recebeu infusao endovenosa de prostaglandina pre-procedimento, independentemente da necessidade hemodinâmica. Na abordagem da APSI, foi utilizada guia de ponta rigida e, mais recentemente, valvotomia com cateter de radiofrequencia. Na maioria dos casos, foi realizada dilatacao sequencial com balao ate atingir 110% a 120% do diâmetro do anel valvar pulmonar. RESULTADOS: Entre 1998 e 2011, 17 neonatos com APSI (idade mediana de 5 dias, peso de 3,1 + 0,6 kg) e 30 neonatos com EP (idade mediana de 12 dias, peso medio de 3 + 1,4 kg) foram tratados em um servico terciario. Na APSI, 14 pacientes foram abordados com guia rigida, com sucesso de 71,4%, e 3 com radiofrequencia, com sucesso de 100%. Na EP, o sucesso foi alcancado em todos os casos. O obito hospitalar foi de 23,5% no grupo com APSI e de 3,3% no grupo com EP, nenhum relacionado ao procedimento percutâneo. Na evolucao a medio prazo, a taxa de reintervencao por reestenose foi de 21,4% no grupo com APSI e de 10% no grupo com EP. CONCLUSOES: A valvoplastia pulmonar na EP e na APSI apresenta resultados clinicos e hemodinâmicos aceitaveis, desde que se observem caracteristicas anatomicas favoraveis e se mantenha a patencia do fluxo pulmonar ate o procedimento. A morbidade e a mortalidade dos portadores de EP critica sao mais baixas que as de portadores de APSI.

Abstract 17889: Sequential Side-Main-Side Branch Balloon Dilation - Sms Technique - As an Alternative to Final Kissing Balloon Inflation in Bifurcation Lesions Treated with Provisional Stenting

Introduction. Final kissing balloon inflation is recommended in provisional stenting in order to accommodate the stent to the bifurcation anatomy. However KBI induces an asymmetry in the proximal stent and does not totally correct the deformation induced under the side branch origin after isolated SB dilation. Objective. To evaluate with IVUS the scaffolding and changes in stent geometry with a new sequential balloon dilation technique which we named SMS-technique. Methods. 63 patients with a true bifurcation coronary lesion (LM 4, LAD 47, LCx 10 and RCA 2) were treated with the SMS technique (Figure). The stent diameter was selected using the distal main branch (MB) reference, then (S) side branch balloon angioplasty was performed with a balloon selected according to its diameter. (M) another balloon, selected according to the proximal main branch reference diameter, was inflated proximally and at the carinal region. (S) final balloon angioplasty of the side branch (SB). An IVUS study was performed at each step. Results. Primary success was obtained in all lesions. Two patients needed a second stent. The table shows the quantitative IVUS findings at each step (*p<0,01). After SMS technique, complete apposition at the proximal stent segment was achieved in all cases. No cases of stent thrombosis were recorded. Conclusion. The SMS technique provides optimal apposition of the stent at the proximal segment of the MB and correction of the stent deformation under the SB origin.

Balloon Angioplasty to Facilitate Autogenous Arteriovenous Access Maturation: A New Paradigm for Upgrading Small-Caliber Veins, Improved Function, and Surveillance

Balloon angioplasty maturation is emerging as an important method to increase utilization and improve function of autogenous arteriovenous hemodialysis accesses (AVFs). Through the sequential dilation of small veins, large-diameter AVFs can be created with the inherent benefits of easier cannulation, greater overall surface area, improved patency, and fewer complications. A usable AVF can be created in a shorter amount of time, decreasing the need for dialysis catheters. In addition, selective angioplasty of the AVF inflow and outflow can facilitate improved flow rates and increase access longevity. Our approach, including primary balloon angioplasty during AVF creation, sequential balloon angioplasty maturation, and surveillance fistulagrams will be presented.

Sp699 Pancreatic Necrosectomy via Percutaneous Self-Expandable Metal Stent Placement

gastric wall to adhere to the abdominal wall before proceeding with ERCP. At our institution we have developed a novel way of EUS guided, fluoroscopic assisted access of gastric remnant followed by sutured gastropexy and subsequent ERCP, all in one session. We describe a series of three such cases. Endoscopic methods: The echo-endoscope was inserted trans-orally and advanced to the gastric pouch or the Roux limb. The remnant stomach was identified using sonographic features and was punctured across the pouch or roux limb wall using a 19G needle pre-loaded with 0.025 guidewire. Radioopaque contrast injection and fluoroscopy were used to confirm needle position. After advancing guidewire the remnant stomach was maximally inflated with air injection through the needle and the best point of percutaneous entry on the abdominal wall was chosen. An 18-gauge introducer needle was inserted into the lumen of the gastric remnant and a 0.035 wire advanced. The wire track was serially dilated and a gastroscope inserted into the remnant. The gastric wall was now secured to the anterior abdominal wall using full thickness sutures. The gastroscope was removed and a 15mm laproscopy port inserted for duodenoscope access. Clinical implications: This novel, one setting minimally invasive approach allows access to remnant stomach and upper GI tract for the purposes of diagnostic and therapeutic endoscopy/ERCP. It allows the use of duodenoscope for difficult cannulation and precise therapeutic ERCP manouvers such as bliary and pancreatic sphioncterotomy. As the gastric wall is secured to anterior abdominal wall with full thickness sutures, one does not run into the risk of dehisence and intra-peritoneal leakage of gastric contents. The use of EUS to access gastric remnant and maximal insufflation alllows for identification of the best point of per cutaneous puncture for gastrostomy tube thus reducing post operative complications and pain. This technique allows the gastrostomy placement and ERCP to be done in the same setting thus reducing health care costs and patient visits.

ABSORB BVS Implantation in Bifurcation Lesions – Current Evidence and Practical Recommendations

The introduction of the ABSORB bioresorbable vascular scaffold (BVS) provides a new tool for stenting in interventional cardiology. Initially, relatively simple coronary artery lesions were treated with this novel device; nowadays, we are gaining clinical experience when treating a wide variety of lesions with the ABSORB BVS, including bifurcation lesions. Unfortunately, data are limited in terms of the use of the ABSORB BVS in coronary bifurcation lesions, so little is known about the safety and feasibility of these procedures. Bench testing and case reports showed that single provisional scaffold placement is feasible with fenestration of the scaffold towards the side branch and sequential non-compliant balloon inflation in the side and main branches. However, no prospective randomised clinical data with optical coherence tomography (OCT) imaging for different bifurcation stenting techniques are available. Based on the available data and our own experience we would recommend the use of the provisional single scaffold technique and only to fenestrate the scaffold if a severely pinched ostium combined with impaired flow seen on angiogram.

ABSORB BVS Implantation in Bifurcation Lesions - Current Evidence and Practical Recommendations.

The introduction of the ABSORB bioresorbable vascular scaffold (BVS) provides a new tool for stenting in interventional cardiology. Initially, relatively simple coronary artery lesions were treated with this novel device; nowadays, we are gaining clinical experience when treating a wide variety of lesions with the ABSORB BVS, including bifurcation lesions. Unfortunately, data are limited in terms of the use of the ABSORB BVS in coronary bifurcation lesions, so little is known about the safety and feasibility of these procedures. Bench testing and case reports showed that single provisional scaffold placement is feasible with fenestration of the scaffold towards the side branch and sequential non-compliant balloon inflation in the side and main branches. However, no prospective randomised clinical data with optical coherence tomography (OCT) imaging for different bifurcation stenting techniques are available. Based on the available data and our own experience we would recommend the use of the provisional single scaffold technique and only to fenestrate the scaffold if a severely pinched ostium combined with impaired flow seen on angiogram.

Primary balloon angioplasty plus balloon angioplasty maturation to upgrade small-caliber veins (

Small-diameter veins are often a limiting factor for the successful creation of arteriovenous fistulas (AVFs). This study evaluated the use of intraoperative primary balloon angioplasty (PBA) as a technique to upgrade small-diameter veins during AVF creation. Sequential balloon angioplasty maturation (BAM) was evaluated as a technique to salvage failed fistulas, expedite maturation, and improve the patency of AVFs after PBA. Sixty-two PBAs were performed in 55 patients with an intent-to-treat using an all-autologous policy. PBAs of veins were performed just before AVF creation using 2.5- to 4-mm angioplasty balloons (1- to 1.5-mm larger than the nominal vein diameter). PBAs were performed through the spatulated end of the vein for a length of up to 8 cm using hydrophilic guidewires and hand inflations without fluoroscopy. BAM was performed in 53 of the 62 PBAs at 2, 4, and 6 weeks after the PBA. Successful outcome was determined as the functional ability to use the fistula for hemodialysis without surgical revision. Of the 62 PBAs, 53 (85.4%), comprising 47 of the original AVFs and 6 new site AVFs created at other sites, remained patent and subsequently underwent BAM with a resulting functional AVF. Fifteen of the 47 original AVFs: 14 due to occlusion; one AVF with a steal was ligated. Seven of the 14 fistulas that occluded were salvaged using recanalization techniques during sequential BAMs. Two of the seven fistulas that were not salvaged required AVGs (3%), and five patients underwent redo AVFs using alternative veins. These five cases were also performed using PBAs and BAMs technique. One patient with a functioning fistula underwent intentional ligation for steal syndrome and also underwent an alternative site AVF, PBA, and BAM. At 3 months, 53 AVFs were functional and successfully used for dialysis. Overall, a working AVF was obtained at the initial site in 47 of 55 patients (85.4%), and 53 (96.3%) received working AVFs that were functioning for dialysis access. Small or suboptimal veins can undergo PBA and then be matured to create functioning AVFs <or=2 months. Overall, >90% autogenous AVF rates can be achieved using PBA and BAM. BAM can be successfully used to mature AVFs created from small veins and salvage thrombosed AVFs in many cases. The use of these techniques may decrease the number of patients requiring AVGs and indwelling catheters.

Infantile Cricopharyngeal Achalasia Responsive to Sequential Balloon Dilatations

Infantile Cricopharyngeal Achalasia Responsive to Sequential Balloon Dilatations

The influence of thermal treatment on the mechanical characteristics of a PLLA coiled stent

We studied the effects of thermal treatment on the expansive characteristics of a coil-within-coil Poly(L-lactic acid) (PLLA) fiber stent developed at our institution to improve its mechanical performance and reproducibility. Following fabrication, furled stents were thermally treated at 62 degrees C for 25 min. The mechanical characteristics were measured compared with those of untreated stents when both were expanded via sequential balloon catheter pressure loading up to 12 atm. Treated stents reached full diameter at 3 atm and maintained that diameter despite further pressure increases. Using measurements of pressure, diameter, and axial length, we calculated the sequential mechanical work required to unfurl the stent. The mechanical work for complete unfurling of treated stents was significantly less than that required for untreated controls. Little axial dimensional change was observed for treated stents. Treated stents exhibited higher stiffness than controls at all pressure levels and also demonstrated higher resistance to external pressure-induced collapse, as measured in a special apparatus developed in our laboratory. Differential scanning calorimetry measurements indicated higher crystallinity values for fibers used in treated stents compared with controls. SEM examination of striations revealed that treated stents underwent less twist than controls following balloon-induced unfurling. The results indicate that, thermal treatment improves the reorientation and realignment of fiber crystalline structure, and favorably influences on the fiber stress-strain behavior and the expansive mechanical characteristics of the PLLA fiber stents.

Sequential Endoscopic Papillary Balloon Dilatation Following Limited Sphincterotomy for Common Bile Duct Stones

Endoscopic papillary balloon dilatation (EPBD) has been recently used in conjunction with endoscopic sphincterotomy (EST) for the removal of common bile duct (CBD) stones. The present study was aimed at assessing the safety and outcome of sequential EPBD following EST for CBD stones. A total of 74 patients (43 females, mean age 41 years) with > or = 10-mm stone(s) in the CBD were selected for the procedure, which included limited EST followed by EPBD with balloon dilators of 10-18 mm in size. Eleven patients had undergone EST and unsuccessful stone removal earlier. Forty-nine patients had symptoms of CBD stones, while 25 were detected on imaging. Eleven patients had previous CBD stent in situ and four had T-tube in situ. The stone size was 10-12 mm in 34, 13-14 mm in 26, and > or = 15 mm in 14 patients. Thirty-one patients had a single stone, while 43 had > or = 2 stones. The successful removal of stones was achieved in 68 (91.9%) patients; 62 in the first attempt, five in the second, and one in the third. Six patients were deemed to be "failures." In two of them, the stones could be removed after mechanical lithotripsy. Complications were seen in 16 patients, with self-limiting pain in 13, self-limiting ooze in five, melaena in one, and mild pancreatitis in two. One patient had impaction of the dormia basket. We conclude that EPBD following EST is safe and effective in removing stones > or = 10 mm in size in over 90% of patients.

Ethanol Abolishes Ischemic Preconditioning in Humans

This study sought to assess the effect of acute alcohol intake on ischemic preconditioning (IPC) in humans using the clinical model of 2 sequential balloon inflations during a percutaneous coronary intervention (PCI). Ischemic preconditioning is the most potent form of endogenous myocardial protection from irreversible ischemic injury. Experimental observations suggest that acute ethanol administration might abolish IPC. We studied 30 consecutive patients (22 men, mean age 65 years) undergoing elective coronary angioplasty who were randomized to receive an oral dose of 40 g ethylic alcohol (administered as 149 ml of Gordon's Gin) or 149 ml of water 30 min before PCI. Intracoronary electrocardiogram was continuously monitored to assess the greatest ST-segment elevation or depression from baseline. In placebo-treated patients, the change of ST-segment shift during the second inflation was significantly smaller than that during the first inflation (19.3 +/- 9.1 vs. 15.7 +/- 8.7, p = 0.005). In contrast, in gin-treated patients, the change of ST-segment shift during the second inflation was significantly greater than that during the first inflation (18.7 +/- 7.2 vs. 22 +/- 10, p = 0.03). The group-inflation interaction for ST-segment changes was highly significant (p < 0.001). This randomized, prospective study in humans shows that administration of a moderate dose of ethanol abolishes IPC occurring during sequential episodes of myocardial ischemia and is associated with worsening ischemia. Based on our study, intake of moderate to high doses of alcoholic beverages should be avoided in patients at high risk of acute myocardial infarction.

Surgical Thrombectomy for Thrombosed Dialysis Grafts: Comparison of Adjunctive Treatments

Vascular surgeons often encounter dialysis graft failure in hemodialysis patients during their daily practice. Despite advances in percutaneous treatment, there remains a role for surgical thrombectomy of thrombosed dialysis grafts. This study was designed to investigate the long-term outcome of dialysis graft thrombectomy and to examine the indications for and effectiveness of therapies adjuvant to Fogarty thrombectomy. Surgical outcomes of 590 consecutive dialysis graft thrombectomies performed between 2001 and 2003 were retrospectively reviewed. The 590 cases were classified into four groups based on the procedure performed adjuvant to Fogarty thrombectomy: group A, surgical thrombectomy by Fogarty thrombectomy catheter alone; group B, thrombectomy plus intraoperative angioplasty of graft outlet; group C, thrombectomy plus sequential balloon angioplasty in subsequent intervention; group D, thrombectomy plus graft outlet surgical revision. Age, gender, co-morbidity, and primary patency of grafts were reviewed and analyzed. The four groups exhibited similar demographic features and comorbidities (p>0.05). Mean primary patency in the four groups was 1.99+/-4.02, 7.21+/-7.61, 8.35+/-9.53, and 7.26+/-6.99 (months), respectively. Survival curves for each group were determined by Kaplan-Meier methods. Primary patency in group A was statistically inferior to all of the other three groups, whereas groups B, C, and D did not significantly differ with regard to graft patency. Surgical thrombectomy alone is inadequate for treating a thrombosed dialysis graft. The underlying graft outlet stricture requires direct surgical revision or balloon angioplasty during surgery or intervention in the angiography suite to ensure long-term patency of the graft.

Minimally Invasive Guided Bone Regeneration

Guided bone regeneration (GBR) is indicated when there is a volume deficiency of the residual ridge that prohibits implantation or optimal implant installation for esthetic and functional needs. Our objective is to describe a new minimally invasive GBR and report its clinical application in several patients. A vertical incision is made mesial to the augmentation zone. The periosteum is initially elevated with a miniature chisel, and then through a series of sequential balloon inflations. This yields a tunnel with adequate space for membrane insertion, decortication, and grafting with substitute bone and platelet rich fibrin (PRF) filling. Primary closure is obtained by 2 or 3 simple interrupted sutures. Vertical and horizontal gains were measured on computerized tomography obtained before and 5 to 6 months after the procedure. Eleven patients were treated with this procedure. There were no significant adverse events. The range of vertical gain was 2.4 to 5.1 mm, while horizontal gain measured 1.3 to 3.9 mm. Implants were successfully placed in 6 patients.

Comparative Study of Degree of Renal Trauma Between Amplatz Sequential Fascial Dilation and Balloon Dilation During Percutaneous Renal Surgery in an Animal Model

To compare two commonly used methods of dilation, the Amplatz sequential fascial (ASF) and the balloon dilator, in a porcine model. Fourteen kidneys from 9 female pigs were used for this experiment. One kidney of each pig underwent ASF dilation and the other underwent balloon dilation using the Nephromax balloon. This was achieved after percutaneous renal puncture with an 18-gauge needle under fluoroscopic guidance. The effects of both methods of dilation were assessed immediately in 1 pig, after 24 hours in 3 pigs, at 4 weeks in 4 pigs, and at 6 weeks in 1. The animals were killed, and the kidneys were removed for gross and histologic examination. Grossly, the ASF dilated tracts appeared rounded and the balloon dilated tracts appeared V-shaped with lateral fragmentation within 24 hours. No obvious gross differences were noted at 4 to 6 weeks between the two methods of dilation, with both appearing as fine scars. Histologically, minor differences were seen at 4 to 6 weeks, with slightly more abscesses and larger scar formation in the kidneys that underwent ASF dilation than in the balloon dilation group. In this porcine animal model, the degree of renal trauma induced by the ASF dilators and the balloon dilators during percutaneous renal surgery seems to be comparable. The acute and chronic renal parenchyma effects of both methods of tract dilation were almost similar. The choice of nephrostomy tract dilation should be by physician preference.

Minimally Invasive Antral Membrane Balloon Elevation Followed by Maxillary Bone Augmentation and Implant Fixation

The posterior maxillary segment frequently suffers from insufficient bone mass to support dental implants. Current bone augmentation methods, including the lateral maxillary approach (ie, hinge osteotomy) and sinus elevation by osteotome, have many shortcomings. The objective of our study was to assess the safety and efficacy of minimally invasive antral membrane balloon elevation (MIAMBE) followed by bone augmentation and implant fixation (executed during the same procedure). Alveolar crest exposure and implant osteotomy were followed by sequential balloon inflations yielding > 10 mm MIAMBE. A mix of autologous fibrin and bone particles with bone speckles was injected beneath the antral membrane. Implants were fixated into the osteotomies, and primary closure was performed during the same sitting. A total of 24 patients were enrolled. Successful conclusion of this procedure was accomplished in 91.6% of the initial 12 patients and 100% in the second dozen cases without significant complications. Patient discomfort was minimal. Long-term follow up revealed satisfactory bone formation, resulting in adequate implant stability. We conclude that the protocol of MIAMBE results in an excellent success rate, low complication rate, minimal discomfort, and long-term safety and durability. Because it requires only basic equipment and a short learning curve, this clinical approach should be widely employed.

A Model of Neural Cross-Talk and Irritation in the Pelvis: Implications for the Overlap of Chronic Pelvic Pain Disorders

Irritable bowel syndrome, interstitial cystitis, and other chronic pelvic pain (CPP) disorders often occur concomitantly. Neural cross-talk may play a role in the overlap of CPP disorders via the convergence of pelvic afferents. We investigated the hypothesis that afferent irritation of one pelvic organ may adversely influence and sensitize another via neural interactions. We measured pelvic organ smooth muscle and striated muscle reflexes during micturition and colorectal distention (CRD) in urethane-anesthetized rats. The effects of acute cystitis on distal colonic sensory thresholds to CRD and the effects of acute colonic irritation on micturition parameters were assessed. External urethral sphincter (EUS) electromyography (EMG) was typical for the rat, with phasic firing during micturition. External anal sphincter EMG also showed phasic firing during micturition in synchrony with EUS activity but, in addition, showed both tonic bursts and phasic firing independent of EUS activity. Before bladder irritation, graded CRDs to 40 cm H2O produced no notable changes in abdominal wall EMG activity. Following acute bladder irritation, dramatic increases in abdominal wall EMG activity in response to CRD were observed at much lower distention pressures, indicating colonic afferent sensitization. Analogously, following acute colonic irritation, bladder contraction frequency increased 66%, suggesting sensitization of lower urinary tract afferents. We report compelling evidence of bidirectional cross-sensitization of the colon and lower urinary tract in a novel experimental model. This cross-sensitization may account for the substantial overlap of CPP disorders; however, further studies are needed to fully characterize these pathways.

Long Term Plastic Stent Treatment for Benign Bile Duct Strictures: Not Always a “Benign” Course

Introduction: Long-term treatment of benign bile duct strictures (BBDS) with polyethylene stents is undertaken in many pts who are not suitable candidates for surgery and have failed sequential balloon dilation and stent placement. The clinical course, complications, and outcome of long-term stent placement in this patient group have only recently been studied. Aim: We retrospectively analyzed the course of pts with BBDS treated long-term with ERCP and stent placement to determine the frequency and severity of complications, hospitalizations related to biliary disease, long-term outcome, and factors which may influence success of treatment. Methods: Pts with BBDS treated with polyethylene stents for >2 years were studied. All patients refused surgery, were poor candidates, or failed a course of sequential stricture dilation and stenting. Stent placement was performed with standard techniques; the interval, size, and number of stents placed at ERCP were determined by the endoscopist. Data retrieved included patient demographics, etiology of stricture, findings at cholangiography, and complications. Hospitalizations due to ERCP or biliary tract disease, comorbid illness and clinical course were obtained from the electronic chart. Results: 11 pts (7 males, 4 females, mean age 62, range 43 - 82) were treated for a mean of 5 years (range 2 to 10 years). Overall, 152 ERCPs were performed with a mean of 13.8 per pt (range 6 to 32). Only one (0.7%) had a post ERCP complication: cholangitis, mild by Cotton criteria. Stents were changed at 4.3 months on average. 6 of 8 (75%) pts treated with scheduled stent changes and all pts stented prn developed biliary sludge. This occurred at a mean 11.4 months from the first ERCP (range 2 to 31 months). Eight pts (73%) required hospitalization for cholangitis with an average stay of 8.5 days (range 6-28 days). Three pts required 2 or more hospitalizations. Two pts died due to biliary disease 3.5 & 4 years into treatment. Need for early stent change, hospitalization, the emergence of intraductal sludge or death could not be correlated to age, sex, number of comorbid illnesses or bilirubin or liver enzymes. Conclusion: 82% of pts treated for benign biliary strictures long-term develop intraductal sludge and require one (73%) or more (27%) hospitalizations as a direct result of their biliary disease and treatment. Repeated biliary stenting in BBDS carries significant morbidity for the patient in the long term. These data should be considered when deciding to begin with long term stent therapy.

Ischemia in three left ventricular regions: Insights into the pathogenesis of acute ischemic mitral regurgitation

Background: Acute posterolateral left ventricular ischemia in sheep results in ischemic mitral regurgitation, but the effects of ischemia in other left ventricular regions on ischemic mitral regurgitation is unknown. Methods: Six adult sheep had radiopaque markers placed on the left ventricle, mitral annulus, and anterior and posterior mitral leaflets at the valve center and near the anterior and posterior commissures. After 6 to 8 days, animals were studied with biplane videofluoroscopy and transesophageal echocardiography before and during sequential balloon occlusion of the left anterior descending, distal left circumflex, and proximal left circumflex coronary arteries. Time of valve closure was defined as the time when the distance between leaflet edge markers reached its minimum plateau, and systolic leaflet edge separation distance was calculated on the basis of left ventricular ejection. Results: Only proximal left circumflex coronary artery occlusion resulted in ischemic mitral regurgitation, which was central and holosystolic. Delayed valve closure (anterior commissure, 58 ± 29 vs 92 ± 24 ms; valve center, 52 ± 26 vs 92 ± 23 ms; posterior commissure, 60 ± 30 vs 94 ± 14 ms; all P <.05) and increased leaflet edge separation distance during ejection (mean increase, 2.2 ± 1.5 mm, 2.1 ± 1.9 mm, and 2.1 ± 1.5 mm at the anterior commissure, valve center, and posterior commissure, respectively; P <.05 for all) was seen during proximal left circumflex coronary artery occlusion but not during left anterior descending or distal left circumflex coronary artery occlusion. Ischemic mitral regurgitation was associated with a 19% ± 10% increase in mitral annular area, and displacement of both papillary muscle tips away from the septal annulus at end systole. Conclusions: Acute ischemic mitral regurgitation in sheep occurred only after proximal left circumflex coronary artery occlusion along with delayed valve closure in early systole and increased leaflet edge separation throughout ejection in all 3 leaflet coaptation sites. The degree of left ventricular systolic dysfunction induced did not correlate with ischemic mitral regurgitation, but both altered valvular and subvalvular 3-dimensional geometry were necessary to produce ischemic mitral regurgitation during acute left ventricular ischemia.J Thorac Cardiovasc Surg 2003;125:559-69

Preconditioning effect during coronary angioplasty in patients with stable angina pectoris.

To determine whether collateral recruitment is involved in the preconditioning effect on the electrocardiogram, chest symptoms, and lactate metabolism during coronary angioplasty in patients with stable angina pectoris. Sixteen patients with stable angina pectoris underwent three consecutive 2-min balloon inflations 5-min apart. The greatest ST elevation (deltaSTmax), the sum of ST elevations in all leads (sum(ST)), and QT dispersion (QTd) were measured at the end of each balloon inflation. Chest pain score was evaluated on a scale ranging from no pain (0) to the most severe pain (10). Lactate extraction ratio (LER) was determined by simultaneous blood sampling from the aorta and the coronary sinus. Collateral flow index (CFI) was derived from simultaneous measurements of mean aortic pressure and coronary wedge pressure obtained from a pressure guidewire during balloon inflation. Significant decreases were noted in deltaSTmax (3.3+/-2.1 vs. 3.0+/-1.9 vs. 2.6+/-1.8 mm, p<0.01), sum(ST) (9.7+/-7.2 vs. 8.5+/-6.1 vs. 6.9+/-5.3 mm, p<0.01), QTd (55.3+/-13.8 vs. 46.9+/-9.0 vs. 42.5+/-10.0 ms, p<0.01), and chest pain score (4.3+/-3.1 vs. 2.8+/-2.6 vs. 1.4+/-1.5, p<0.01) during the three sequential balloon inflations. LER significantly increased (-55.5+/-47.8 vs. -36.7+/-34.3 vs. -19.6+/-26.2%, p<0.01), indicating decreased lactate production. No significant difference was observed in CFI (0.16+/-0.10 vs. 0.15+/-0.10 vs. 0.15+/-0.10). Repeated balloon inflations during coronary angioplasty elicited a preconditioning effect on ST-segment shift, QT dispersion, chest pain, and lactate production that does not involve collateral recruitment.