Dense Scar Research Articles

The frontal intersinus septum takedown procedure

Unilateral frontal sinus obstruction presents a surgical challenge when outflow tract osteoneogenesis or dense scarring is present. Frontal sinus obliteration is often employed as a last resort, but this procedure has potential long-term complications. In some cases, endoscopic modified Lothrop or unilateral drillout procedures may be effective options; however, restenosis rates are often high. Here we report our experience using frontal intersinus septum takedown (FISST) to address unilateral obstruction while preserving the opposite frontal outflow tract. A retrospective review was performed of 12 patients with unilateral frontal sinus opacification due to irreversible frontal recess obstruction who underwent FISST. Surgical outcomes were assessed based on symptoms and computed tomography (CT) resolution of frontal sinus disease. All 12 patients undergoing FISST had significant improvement in their symptoms. Ten postoperative CT scans were available for review, all showing continued patency of the interfrontal connection, and nine out of 10 with resolution of radiographic frontal sinus disease. Eleven of the procedures were performed via trephination, and one was achieved endoscopically. In patients with one obstructed frontal sinus and a functional contralateral sinus, removal of the intersinus septum allows for adequate sinus drainage and significant clinical improvement. The success of FISST may be surprising given knowledge of mucociliary clearance patterns, but may be effective because of the naturally dependent position of the frontal sinus ostium.

High scrotal approach for secondary orchidopexy in cases of recurrent and iatrogenic undescended testes

Background/purpose Secondary orchidopexy is often difficult due to altered anatomy and dense scarring following previous operation. The aim of this study was to assess the feasibility and results of secondary transcrotal orchidopexy for the palpable recurrent and iatrogenic undescended testes. Patients and methods The case records of all children who underwent secondary orchidopexy through high scrotal incision during the study period May 2004 to April 2009 were retrospectively reviewed. Results Redo orchiopexy using the high scrotal approach was used to treat 41 testes during a 4-year period. Eight of these cases occurred after an inguinal hernia repair and 33 cases occurred after a previous orchiopexy. At follow-up, 39 of the 41 orchidopexies (95.2%) testes were found viable. Two testes (4.8%) were recorded to have atrophied. Conclusion This study shows that secondary orchidopexy through a high scrotal incision is a safe, effective, and applicable technique for recurrent and iatrogenic undescended testes. Keywords: high scrotal approach, redo orchidopexy, undescended testis

Effects of acutely lowering intraocular pressure on the results of multifocal visual evoked potential testing

There have been many reports in the literature on the apparent reversal of optic nerve cupping in patients with glaucoma after lowering intraocular pressure (IOP) on clinical examination, as well as improvement in visual field testing, and increased nerve fibre layer thickness on optical coherence tomography. No studies to date have looked at improvement of multifocal visually evoked potentials (mfVEP) after lowering IOP. This was a prospective study of twenty consecutive patients with elevated IOP seen in the glaucoma department of Wills Eye Institute. Patients who met the inclusion criteria for this study had a complete eye examination including IOP measurement and underwent testing with mfVEP, Heidelberg Retinal Tomograph (HRT) and static achromatic automated perimetry with SITA-Standard 24-2 program Humphrey visual field (HVF) studies at baseline and 2 h post-IOP reduction. A minimum of 30% IOP reduction was required. IOP changes were then compared with various parameters of mfVEP, HRT and HVF using Spearman rank correlation coefficients. The Spearman rank correlation values between change in IOP versus various parameters were calculated: Accumap severity index (ASI), 0.37 (p = 0.14); Accumap superior hemifield, 0.049 (p = 0.85); Accumap inferior hemifield, 0.030 (p = 0.91); HVF mean deviation, 0.081 (p = 0.76); HRT rim area, 0.17 (p = 0.51); HRT cup area, -0.006 (p = 0.98). Weak positive but insignificant correlations were seen for all parameters except cup area. This pilot study failed to confirm statistically significant correlations between IOP reduction and changes in Accumap, HVF and HRT measures, although positive correlations were seen for most measures.

LONG-TERM RESULTS OF SUBSTRATE-BASED VENTRICULAR TACHYCARDIA ABLATION IN PATIENTS WITH PREVIOUS MYOCARDIAL INFARCTION. IDENTIFICATION OF ANATOMICAL AND ELECTROPHYSIOLOGICAL SUCCESS PREDICTORS

Methods: We analyzed 60 patients (age 67±9, LVEF: 30±11%) with chronic myocardial infarction who underwent substrate based VT ablation (SBVTA). Electroanatomic maps were obtained to measure the scar (≤1,5 mV) and dense scar ((≤ ,5 mV ) and to delimit the scar borders. The targets of SBVTA were all E-IDC and CC of the scar tissue. Results: Ablation targeted E-IDC and CC in 95% and 75% of patients, in 5 % the ablation targeted multicomponent electrogram from the scar border where pace-mapping reproduced VT morphology. The ablation area was 14±10 cm 2, no major life-threatening complications/incessant VT were observed after the procedure. During a median follow-up of 35 months 57% of patients remained free of VT recurrences. Patients with an above-median dense scar extension (25 cm 2 ) were at higher risk for VT recurrence compared with those with a below-median (65% versus 24%, p<0.0001, median follow-up 31 vs. 39 months, p: 0.1). Multivariable analysis showed that scar extension was the only predictors of VT recurrence (p<0.004). Conclusion: In patients with a prior MI SBVTA is safe and effective, the extent of dense scar provides incremental prognostic value post MI smvt recurrence

Characterization of myocardial scars: Electrophysiological imaging correlates in a porcine infarct model

Definition of myocardial scars as identified by electroanatomic mapping is integral to catheter ablation of ventricular tachycardia (VT). Myocardial imaging can also identify scars prior to ablation. However, the relationship between imaging and voltage mapping is not well characterized. The purpose of this study was to verify the anatomic location and heterogeneity of scars as obtained by electroanatomic mapping with contrast-enhanced MRI (CeMRI) and histopathology, and to characterize the distribution of late potentials in a chronic porcine infarct model. In vivo 3-dimensional cardiac CeMRI was performed in 5 infarcted porcine hearts. High-density electroanatomic mapping was used to generate epicardial and endocardial voltage maps. Scar surface area and position on CeMRI were then correlated with voltage maps. Locations of late potentials were subsequently identified. These were classified according to their duration and fractionation. All hearts underwent histopathological examination after mapping. The total dense scar surface area and location on CeMRI correlated to the total epicardial and endocardial surface scar on electroanatomic maps. Electroanatomic mapping (average of 1,532 ± 480 points per infarcted heart) showed that fractionated late potentials were more common in dense scars (<0.50 mV) as compared with border zone regions (0.51 to 1.5 mV), and were more commonly observed on the epicardium. In vivo, CeMRI can identify areas of transmural and nontransmural dense scars. Fractionated late diastolic potentials are more common on the epicardium than the endocardium in dense scar. These findings have implications for catheter ablation of VT and for targeting the delivery of future therapies to scarred regions.

The infarct characteristics on magnetic resonance imaging and ventricular tachycardia: do we see what we need to see?

This editorial refers to ‘The heart rate of ventricular tachycardia following an old myocardial infarction is inversely related to the size of scarring’ by L. Woie et al., on page 864. The underlying mechanism of most ventricular tachycardias (VTs) after myocardial infarction (MI) is reentry involving areas of ventricular scar. Dense fibrous scars alone cannot cause arrhythmias; however, when surrounded by bundles of surviving myocytes in the peri-infarction zone, an arrhythmogenic substrate may arise. Areas of dense fibrosis intersperse with surviving myocardial bundles and form regions of conduction block that define reentry circuit borders. The presence of fibrosis between these surviving bundles prolongs the pathway for impulse propagation, creating slow conduction through the scar.1 The complex structure of these scars is likely to determine reentrant circuit characteristics and thereby VT characteristics.2 Late gadolinium-enhancement cardiac magnetic resonance (LGE-CMR) has increasingly been used to visualize the three-dimensional (3D) geometry of myocardial fibrosis and has become the gold standard for detection of non-transmural scars because of its superior spatial resolution.3 Woie et al .4 have addressed an interesting question of whether myocardial scar characteristics as visualized and defined by LGE-CMR correlate with VT characteristics, specifically with the VT cycle length (VTCL). They hypothesized that the rate of spontaneous VTs is related to the size of the post-infarction scar or its border zone. They studied 24 patients with remote MI and indication for implantation of an internal cardioverter-defibrillator for primary or secondary prevention who underwent LGE-CMR for quantification of left ventricular (LV) volumes, function, size of core infarct, and size of the infarct border zone prior to device implantation. Patients were followed every 3 months during the first year after implantation. Twenty out of 24 patients had VTs with a median VTCL of 325 ms (range 239–438 ms). None of …

Endocardial and Epicardial Ablation of Ventricular Tachycardia Associated with Organic Heart Disease

Previous studies have demonstrated the effectiveness of targeting areas for radiofrequency catheter ablation (RFCA) in cases of unmappable ventricular tachycardia (VT) on the basis of voltage mapping using the electroanatomical mapping system. An abnormal area in right and left ventricle mapping was generally defined as 0.1–<0.6 mV, and dense scars as <0.1 mV. The basic linear ablation design criteria were: Lesions must cross through the LVA, where a good pace mapping could be obtained; Lesions must combine between scar and scar within the LVA; and Lesions must extend from the scar to the normal voltage area. RF was not applied to nonarrhythmogenic areas. At 38±18 months follow-up, 93% of the patients were free of VT after one or more endocardial ablations in 29 patients with old myocardial infarction. Failure to ablate VT from the endocardium may require an epicardial mapping in non-ischemic heart disease. The VT substrate of dilated cardiomyopathy is distributed at more epicardial sites than endocardial sites, and a combined endocardial and epicardial ablation may be effective in such cases.

Focal Nodular Hyperplasia in the Livers of Cynomolgus Macaques (Macaca Fascicularis)

Two cases of spontaneous focal hepatic hyperplasia were observed in young female cynomolgus macaques (Macaca fascicularis). Grossly, a single raised nodule was observed in the left hepatic lobe. Histopathologically, the nodule compressed surrounding normal tissue; however, the hepatic cords within the nodule continued to those in the nor mal area except in part. Extensive fibrosis and absence of a normal hepatic triad were observed in the nodule. Thin fibrous septa radiating from the dense central stellate scarring and distended vessels were apparent in one animal. Hepatocytes in the nodule lacked cellular atypia, showed frequent PAS-positive eosinophilic inclusions in the cytoplasm and showed higher positive ratios for PCNA. The present cases resembled focal nodular hyperplasia reported in humans and a chimpanzee.

Ultra High-Density Multipolar Mapping With Double Ventricular Access: A Novel Technique for Ablation of Ventricular Tachycardia

Ultra High-Density Multipolar Mapping With Double Ventricular Access. Analogous to the use of circular loop catheters to guide ablation around the pulmonary veins, it may be advantageous to use a multipolar catheter in the ventricle for rapid mapping and to guide ablation. We describe a technique using double access into the left ventricle for multipolar electroanatomic mapping and ablation of scar-mediated ventricular tachycardia (VT). Double access into the left ventricle was obtained via transseptal technique. Endocardial mapping was performed via the first transseptal sheath using a steerable duodecapolar catheter. Higher density mapping was performed in areas of dense scar (<0.5 mV) and border zone (0.5-1.5 mV). All late potentials (LPs) observed on the 20 poles were tagged and pacemapping was performed at these sites for comparison with the clinical or induced VT 12-lead template. If VT was hemodynamically tolerated, entrainment mapping was attempted at sites demonstrating diastolic activity. Ablation was performed through the second transseptal sheath with an open-irrigated catheter at target sites identified by LPs, pacemapping, and/or entrainment on the duodecapolar catheter. Seventeen patients (88% ischemic cardiomyopathy) underwent electroanatomic mapping and ablation with double transseptal access. The mean number of endocardial mapping points was 819 ± 357 with an average mapping time of 31 ± 7 minutes. The mean number of VTs induced was 2.8 ± 1.6, mean cycle length 418 ms ± 101. LPs were seen in all patients during endocardial mapping with the duodecapolar catheter. Good (56%) and perfect (44%) pacemaps were seen in all patients when performed. Concealed entrainment, guided by the earliest diastolic activity seen on the duodecapolar catheter, was demonstrated in 4 patients (24%). Acute success was achieved in 94% of patients with complete success in 47% and partial success in 47%. The intermediate success rate (free of VT recurrence) was 69%, with an average follow-up of 8 ± 3 months. Mapping and ablation of scar-mediated VT using a multipolar catheter results in ultra high-density delineation of the left ventricular substrate. A novel double ventricular access strategy has the potential to facilitate identification of LPs, pacemapping, and entrainment mapping.

Management of Recalcitrant Bladder Neck Contracture After Radical Prostatectomy for Prostate Cancer

Management of Recalcitrant Bladder Neck Contracture After Radical Prostatectomy for Prostate Cancer

Riboflavin and Ultraviolet Light A Therapy as an Adjuvant Treatment for Medically Refractive Acanthamoeba Keratitis: Report of 3 Cases

To present the first 3 cases of Acanthamoeba keratitis (AK), unresponsive to medical treatment, that were successfully treated with a novel adjunctive therapy using ultraviolet light A (UVA) and riboflavin (B2). Interventional case series. Two patients with confirmed AK and 1 patient with presumptive AK, which were all refractive to multidrug conventional therapy. Two treatment sessions involving topical application of 0.1% B2 solution to the ocular surface combined with 30 minutes of UVA irradiation focused on the corneal ulcer. Clinical examination by slit lamp, confocal microscopy, and histopathology, when available. All patients in these series showed a rapid reduction in their symptoms and decreased ulcer size after the first treatment session. The progress of the clinical improvement began to slow after 1 to 3 weeks of the first application and was then renewed after the second application. All ancillary signs of inflammation mostly resolved after the second treatment session. The ulcers in all patients continued to decrease and were closed within 3 to 7 weeks of the first application. Two patients developed dense central corneal scars, and penetrating keratoplasty was performed for visual rehabilitation. Histopathologic examination of the excised tissue revealed no Acanthamoeba organisms. The remaining patient had no symptoms or signs of infection, both clinically and by confocal microscopy, and was left with a semitransparent eccentric scar that did not affect visual acuity. The adjunctive use of UVA and B2 therapy seems to be a possible alternative for selected cases of medication-resistant AK.

Distribution of late potentials within infarct scars assessed by ultra high-density mapping

Late potential (LP) electrograms represent areas of slow conduction and are often sites critical to reentrant tachycardia circuits. The distribution of LPs within infarct scar is not known. The purpose of this study was to delineate infarct heterogeneity using ultra high-density mapping and to determine the location of LPs with respect to scar architecture. Detailed endocardial (n = 21) and epicardial (n = 8) ultra high-density mapping was performed to delineate the substrate for ventricular tachycardia (VT) in 21 patients with ischemic cardiomyopathy. LP was defined as a low-voltage electrogram (< 1.5 mV) with distinct onset after the QRS. Very late potentials (vLPs) were classified as LPs with onset > 100 ms after the QRS. A mean of 787 ± 391 and 810 ± 375 points in the LV endocardium and epicardium were sampled. Multipolar mapping identified heterogeneous islets (HIs) with relatively preserved electrogram amplitudes (≥ 0.51 mv) within dense scar (8.5 ± 4.9/4.5 ± 2.6 HIs per endocardium/epicardium) in all patients. In maps on which putative VT isthmuses were identified (25/29), 57% of vLP were recorded in or adjacent to HI. An LP-targeted ablation strategy combined with pace mapping achieved acute success in all patients (complete success in 52% and partial success in 48%). After 15 ± 7 months, 65% of patients remained free of VT episodes. Ultra high-density mapping with a multipolar catheter facilitates the delineation of heterogeneous scar architecture at higher resolution. Electrograms within and adjacent to HIs have a higher incidence of vLP, and these sites are frequently critical to reentry. These findings have important implications for substrate-based ablation strategies.

Electrophysiologically guided untethering of secondary tethered spinal cord syndrome

Many patients develop neurological symptoms related to spinal cord tethering after perinatal repair of myelomeningocele. This is referred to as secondary tethered cord syndrome (STCS). The authors describe their methodology and evaluate the intraoperative utility and postoperative outcomes of electrophysiologically guided untethering for STCS. In addition, the authors describe the use of electrophysiological guidance to identify an "autonomous placode" in the untethering of the cord in STCS. The authors retrospectively identified 46 untethering procedures in 38 patients who had undergone perinatal myelomeningocele repair and in whom the index surgery was for tethered cord release at the site of the repair. In all cases, both passive (electromyography) and active (detection of compound muscle action potentials) electrophysiological monitoring was used. The proximity to neural elements was determined based on the current used; eliciting compound muscle action potentials with a <or= 10-mA stimulation was assumed to represent direct neural stimulation. Clinical records were reviewed to evaluate the utility of electrophysiological guidance and patient outcomes. The median age at the time of untethering was 9.5 years (range 0.5-54 years). The median follow-up time was 42 months (range 3-172 months). Progressive bowel and bladder dysfunction, diagnosed either clinically or by cystometrogram, and low-back pain were the most common presenting symptoms. Intraoperative findings indicated that the most common causes of tethering were dense scar (76%) and a tethered placode (39%). Electrophysiological monitoring identified functional neural tissue near tethered elements and provided intraoperative guidance in all cases. In 41% of cases (19 cases), the untethering plan was noted to have been significantly influenced by intraoperative neurophysiological findings. Moreover, an autonomous placode was identified in 6 patients who were nonambulatory preoperatively and had presented with increasing pain and spasticity. In electrophysiologically silent areas, more aggressive dissection and untethering were possible. Symptoms of low-back pain, lower-extremity paresthesia, and lower-extremity spasticity were most likely to improve after untethering surgery (91, 88, and 82%, respectively). Sectioning above the electrophysiologically defined autonomous placode resulted in significant improvement in back pain and lower-extremity spasticity in 5 of 6 patients. There was 1 case of immediate postoperative neurological deterioration (fecal incontinence). All patients remained clinically stable or improved on long-term follow-up, except for 6 (16% of patients) who required a total of 7 additional procedures for recurrent symptoms (median time to repeat surgery 36 months). Complications were noted in 8 cases, including infections and CSF leaks. Surgical untethering of STCS halts progression and often improves preoperative symptoms. Electrophysiological monitoring, using both a threshold-based interpretation system and continuous electromyography monitoring, provides an efficient, effective, and reliable method for intraoperative guidance, thereby limiting iatrogenic injury and providing a means to identify and untether autonomous placodes. Electrophysiological monitoring also allows for more aggressive dissection and untethering in functionally silent regions, possibly decreasing retethering rates.

Surgical management of constrictive pericarditis

Constrictive pericarditis is a disease characterized by marked thickening and dense scarring of the pericardium with pericardial sac obliteration, or calcification of the pericardium. Without treatment this disease is characterized by high morbidity and mortality. To review the surgical management of constructive pericarditis and the post operative challenges. Eleven patients who had pericardiectomy for constructive pericarditis between 2000 and 2005 were studied. Data was obtained from the operating theatre register, histopathological reports and patient's case notes. The mean age was 33 years with a range of 14 to 53 years. There were seven males (63.6%) and four females (36.4%). Seven (63.6%) out of the eleven patients operated were treated for pulmonary tuberculosis. The cause of pericardial constriction in four patients (36.4%) was undetermined. Follow up period was between 4-59 months. The mean follow up was 17.5 months. Seven patients (63.6%) were off diuretics and had no exercise intolerance. Patients were classified using the New York Heart Association (NYHA) n (NYHA) functional and therapeutic classification in class I-V. Two patients preoperatively in class III are now in class I after surgery on low dose diuretics. One patient who had calcific constrictive pericarditis and came in class III was now in class II with diuretics after 3 years of follow up. There was no postoperative mortality. One patient was lost to follow up. Pericardiectomy is a useful procedure for constrictive pericarditis and was beneficial to all the patients in this study with an improvement in their functional capacity. Intensive peri-operative monitoring and management reduced morbidity and mortality.

Complexity of non-iatrogenic ureteral injuries in children: single-center experience

Non-iatrogenic ureteral injuries in children are rare. Only sparse literature reports are available regarding management and outcome. We reviewed our experience in diagnosis and treatment of complex non-iatrogenic ureteral injuries in children. From 2000 to 2010, children who were treated for non-iatrogenic ureteral injuries were reviewed. Patients' characteristics, mechanism of trauma, affected ureteral segment, time of recognition, associated injuries, presentation, mode of treatment and postoperative complications were studied from the medical records of those patients. Five children (four boys and one girl) with a median age of 10 (range 2-15) were treated at our center. Blunt abdominal trauma was documented in three children, while in another two penetrating trauma was inflicted. Associated hepatic tear was noted in one child and bowel injury in another. The affected segment was UPJ in three and mid-ureter in two. All cases presented with Urinoma. Diagnosis was confirmed after fixation of percutaneous nephrostomy and antegrade pyelography in four children, while reterograde pyelography was done in the remaining child. Surgical interventions included uretero-calyceal anastomosis in two, while nephrectomy was necessitated in another two with poor kidney function. In the child to whom retrograde pyelography was done, a double J stent was fixed for 3months and the patient did well. Pediatric non-iatrogenic ureteral injuries are rare. A raised index for suspicion should be considered intra-operatively during initial exploration. Missed injuries are more common and may end in dense scarring and up to nephrectomy.

Long-Term Complications of Minimally Invasive Endometrial Ablation Devices

Background: Endometrial ablations are very effective in treating intractable uterine bleeding. They are much safer than a hysterectomy and the recovery time is shorter. The operative and short-term complications of endometrial ablations are well documented; however, the delayed or long-term complications and their significance are just now being understood. Purpose and Conclusions: This review will thoroughly discuss these delayed complications. The reason these unique problems are occurring is that the ablation procedure attempts to remove all of the endometrium, which exposes myometrium. At the end of the procedure, after the distention media or instrument is removed, the myometrial walls collapse upon each other and have a natural tendency to grow together, causing intrauterine scarring and contracture. If bleeding occurs from persistent or regenerating endometrium trapped behind the scar, it can be obstructed and cause central hematometra, cornual hematometra, postablation tubal sterilization syndrome, retrograde bleeding, and potentially delay the diagnosis of endometrial cancer. From a practical standpoint, it is problematic when a postablation patient returns with abnormal or postmenopausal bleeding. Scarring makes thorough evaluation of the intrauterine cavity difficult. Endometrial biopsies, which are a simple office diagnostic procedure, are no longer reliable. An ultrasound guided hysteroscopy is usually indicted but can be unsuccessful in getting to the tissue because of dense intrauterine scarring that can distort the intrauterine architecture. Even if tissue is obtained, it is difficult to ascertain if it is a complete sample. This is a challenging situation because a hysterectomy is often necessary just to resolve the problem. (J GYNECOL SURG 26:133)

Pirfenidone mitigates left ventricular fibrosis and dysfunction after myocardial infarction and reduces arrhythmias

Post-myocardial infarction (MI) complications include ventricular tachycardia (VT). Excessive non-MI fibrosis, involving the infarct border zone (IBZ) and beyond, is an important substrate for VT vulnerability. This study assessed whether the antifibrotic agent pirfenidone can mitigate fibrosis in remodeling and determined its effects on myocardial function and VT susceptibility in a rodent MI model. We studied 2 groups of rats undergoing MI 1 week prior to treatment: a control group (n = 15) treated with placebo and a pirfenidone group (n = 15). We performed serial echocardiograms, and after 4 weeks of treatment, we conducted electrophysiological and optical mapping studies as well as histology. There was less decline in left ventricular (LV) ejection fraction for pirfenidone-treated rats, 8.6% versus 24.3% in controls (P <0.01). Pirfenidone rats also had lower rates of VT inducibility, 28.6% versus 73.3% in control rats (P <0.05). Furthermore, pirfenidone-treated rats had faster conduction velocities in their IBZs compared with controls, at all pacing cycle lengths (P <0.05). Rats treated with pirfenidone also had smaller infarct dense scar (8.9% of LV myocardium vs. 15.7% in controls, P <0.014), less total LV fibrosis (15% vs. 30% in controls, P <0.003), and less nonscar fibrosis (6.6% vs. 12.6% in controls, P <0.006). Pirfenidone decreased total and nonscar fibrosis in a rat MI model, which correlated with decreased infarct scar, improved LV function, and decreased VT susceptibility. Directly targeting post-MI fibrotic substrates may have a role in limiting infarct-dense scar, improving LV function, and reducing VT vulnerability.

Early Reperfusion During Acute Myocardial Infarction Affects Ventricular Tachycardia Characteristics and the Chronic Electroanatomic and Histological Substrate

Reperfusion therapy during acute myocardial infarction results in myocardial salvage and improved ventricular function but may also influence the arrhythmogenic substrate for ventricular tachycardia (VT). This study used electroanatomic mapping and infarct histology to assess the impact of reperfusion on the substrate and on VT characteristics late after acute myocardial infarction. The study population consisted of 36 patients (32 men; age, 63+/-15 years) referred for treatment of VT 13+/-9 years after acute myocardial infarction. Fourteen patients with early reperfusion during acute myocardial infarction were compared with 22 nonreperfused patients. Spontaneous and induced VTs and the characteristics of electroanatomic voltage maps were analyzed. Twenty-seven patients were treated by radiofrequency catheter ablation. Ten patients (6 nonreperfused) were treated by ventricular restoration with intraoperative cryoablation in 9. During surgery, biopsies were obtained from the resected core of the infarct. VT cycle length of spontaneous and induced VTs was shorter in reperfused patients (reperfused, 299+/-52/270+/-58 ms; nonreperfused, 378+/-77/362+/-74 ms; P=0.01). An electroanatomic patchy scar pattern was present in 71% of reperfused and 14% of nonreperfused patients (P=0.004). The proportion of electroanatomic dense scar was smaller in reperfused patients (24+/-18% versus 45+/-21%; P=0.02). Histological assessment in 10 patients revealed thick layers of surviving myocardium in 75% of reperfused but in none of the nonreperfused patients. Scar size and pattern defined by electroanatomic mapping are different between VT patients with and without reperfusion during acute myocardial infarction. Less confluent electroanatomic scars match with thick layers of surviving myocardium on histology. Early reperfusion and less confluent electroanatomic scar are associated with faster VTs.

Revision of vagal nerve stimulation (VNS) electrodes: review and report on use of ultra-sharp monopolar tip

As a result of the increasingly popularity of vagal nerve stimulation (VNS) for intractable seizures, neurosurgeons not uncommonly encounter cases which require electrode revision. We examine our experience of VNS revision and reports the use of the ultra-sharp monopolar tip for safe dissection and removal of the electrode from the vagus nerve. A retrospective review was performed from January 2000 to Dec 2009 reviewed eight cases of VNS revision. The indications for VNS revision were device malfunction manifesting with increased seizures or increased impedance of the device and infection. The time from initial VNS implantation to revision ranged from 6 to 108 months (mean: 38 months). The entire VNS electrode system, was removed in seven cases and the helical coils were left in-situ in one case who did not derive any benefit from VNS and it was deemed unnecessary to subject the patient to the additional risk of vagal nerve injury. One case had dislodgement of the lower two coils and three cases had dense scarring to the vagus nerve causing high impedance and malfunction. The other three cases demonstrated no fibrotic scar tissue between the helical coils and the vagus nerve. Four cases had replacement of new VNS system but the case of infected VNS stimulator was not replaced as there was no benefit from the device. VNS revision is normally performed in cases of device malfunction or infection and can be safely performed using a combination of ultra-sharp monopolar coagulation and sharp dissection.

The Boston Keratoprosthesis in 2 Patients With Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy

To report the results of Boston keratoprosthesis in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Case 1 is a 36-year-old woman with APECED and ocular history of corneal ulcers in both eyes who presented with severe dry eyes. Her ocular examination showed diffuse corneal vascularization and stromal scarring in the left eye. She underwent Boston type 1 keratoprosthesis, cataract extraction, and sulcus intraocular lens implant in the left eye to improve visual acuity. Case 2 is a 49-year-old man with possible APECED and ocular history of phlyctenular keratitis, recurrent corneal erosions, and scarring presented with dense corneal vascularization and scarring in both eyes. He underwent a Boston type 1 keratoprosthesis, clear lens extraction, and posterior chamber intraocular lens implant in the right eye. The surgeries were uneventful. On postoperative day 1, visual acuity of 20/40 was achieved in both patients and it remained stable during the 2-year follow-up period. There were no postoperative complications seen in either patient. APECED is a rare disorder, which can be associated with bilateral keratitis or diffuse corneal vascularization in addition to systemic findings and ectodermal signs. The Boston type 1 keratoprosthesis is a promising treatment option to improve visual acuity in patients with APECED with corneal involvement.