Supporting the Ross procedure: preserving root physiology while mitigating autograft dilatation

PURPOSE OF REVIEW

The purpose of this article is to describe the optimized approach to nonrepairable aortic valve disease in young adults with a Ross procedure, while preserving the dynamic physiology of the aortic root.

RECENT FINDINGS

As the techniques for supporting pulmonary autografts continue to be refined, and the applicability of the Ross procedure continues to expand, an assessment of the various techniques based on aortic root physiology is warranted. Semi-resorbable scaffolds show promise in ovine models for improving the Ross procedure. Recent long-term outcomes for the Dacron inclusion technique in comparison to more physiologic methods of support emphasize the importance of balancing the prevention of early dilatation with the preservation of root haemodynamics. As this review will synthesize, the dynamic physiology of the root may be preserved even in patients at a higher risk of autograft dilatation.

SUMMARY

The favourable long-term outcomes of the Ross procedure can be partly attributed to the ability of the autograft to restore dynamism to the neoaortic root. Patient-specific modifications that respect root physiology can tailor the Ross procedure to address each patient's risk factors for early dilatation and late failure. As such, the Ross procedure should be recognized as an increasingly favourable solution for a wide spectrum of nonpreservable aortic valve disease in young adults.

Diabetes attenuated age-related aortic root dilatation in end-stage renal disease patients receiving peritoneal dialysis

AIMS/INTRODUCTION

Recently, some data have supported the concept that diabetes is negatively associated with aortic aneurysm. In the present study, we aimed to investigate the relationship between diabetes and cardiac structural and functional characteristics, in particular, aortic root dimensions, in end-stage renal disease (ESRD) patients.

METHODS

ESRD patients receiving peritoneal dialysis for >3 months were consecutively enrolled. Clinical features and echocardiographic parameters were analyzed according to the presence of diabetes history. Correlation analyses were carried out for diabetes mellitus and aortic root dilatation. Multiple logistic regression analysis was carried out to identify variables correlated with aortic root dilatation.

RESULTS

A total of 218 ESRD patients receiving peritoneal dialysis were enrolled. Patients with diabetes showed lower left ventricular internal measurements in end-diastole, left ventricular internal measurements in end-systole and aortic root diameter (ARD)/body surface area (BSA). Worse cardiac diastolic function was also observed in these patients. In addition, the age-related increase of ARD/BSA and ARD/height was attenuated in patients with diabetes. With the increase of ARD/BSA, lower levels of serum creatinine, phosphorus and serum glucose, as well as higher serum high-density lipoprotein cholesterol and apolipoprotein A-1 were also observed. Increased normalized left ventricular internal measurements were shown in patients with greater ARD/BSA. Multiple regression analysis showed that diabetes (odds ratio 0.353, P = 0.015) was an independent correlate of aortic root dilatation, even after correction for age, sex and other clinical confounders in the enrolled patients.

CONCLUSIONS

The present findings shown an inverse association between diabetes and age-related aortic root dilatation in ESRD patients. Diabetes remained to be independently correlated with aortic root dilatation even after adjustment for age, sex and other clinical confounders in ESRD patients.

[High-risk pregnancy in a woman with Marfan syndrome, a bicuspid aortic valve, and a dilated aortic sinus]

A 29-year-old woman with Marfan syndrome, a bicuspid aortic valve, and a dilated aortic sinus (5.2 cm) presented herself in clinic 14 weeks pregnant. She was advised to discontinue the pregnancy due to risk of dissection; however, she decided to continue. She was treated with labetalol (300 mg/day) to reduce blood pressure and was admitted for bed rest from week 30. Her aortic diameter was assessed by echocardiography every 2nd week and remained unchanged. She was treated with betamethason at week 26 and the child was born by a caesarean section in week 35. The post-operative course was uneventful.

A modification of the pulmonary autograft procedure to prevent late autograft dilatation

Although the pulmonary autograft procedure for aortic valve replacement is a commonly utilized option for children, its use is diminishing in adult-aged patients. One commonly cited concern is the tendency for the pulmonary autograft to dilate in the aortic position. This article reviews a technique we have used in 36 patients since October, 2004 that stabilizes the autograft so that it cannot dilate. There have been no operative or late deaths and the autograft has continued to function in 34 patients. Two patients have undergone autograft replacement because of early failure, which we believe was likely related to technical considerations in our early technique (first reported in the 2005 STCVS Pediatric Cardiac Surgery Annual). The technical modifications described in this article have produced a more reliable and reproducible technique and have not resulted in any autograft failures in our experience. One patient with Marfan's syndrome and a bicuspid aortic valve is symptom- and dilation-free 8 years post op, with no autograft or pulmonary homograft insufficiency, normal activity and a stable aortic root by serial echocardiography. Our results suggest that this technique might be applicable for selected adult patients in whom autograft growth is not necessary and for whom the risk of autograft dilatation would provide a reason to avoid a pulmonary autograft procedure.

The isolation, pathogenesis, diagnosis, transmission, and control of avian bornavirus and proventricular dilatation disease

Proventricular dilatation disease (PDD) is a common infectious neurologic disease of birds comprising a dilatation of the proventriculus by ingested food as a result of defects in intestinal motility, which affects more than 50 species of psittacines, and is also known as Macaw wasting disease, neuropathic ganglioneuritis, or lymphoplasmacytic ganglioneuritis. Definitive diagnosis of PDD has been problematic due to the inconsistent distribution of lesions. Since its discovery, avian bornavirus (ABV) has been successfully cultured from the brains of psittacines diagnosed with PDD, providing a source of antigen for serologic assays and nucleic acid for molecular assays. This article provides evidence that ABV is the etiologic agent of PDD. Recent findings on the transmission, epidemiology, pathogenesis, diagnosis, and control of ABV infection and PDD are also reviewed.

Antiteratogenic effect of resveratrol in mice exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin

The effect of resveratrol, an aryl hydrocarbon receptor antagonist, on the teratogenicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was investigated. Pregnant C57BL/6J mice were orally administered resveratrol (50 mg/kg) for 6 consecutive days, from gestational day (GD) 8 to GD13, followed by an oral challenge with TCDD (14 mug/kg) on GD12. TCDD caused severe fetal malformations including cleft palate (40.7%), renal pelvic dilatation (100%, mean score 3.060), and ureteric dilatation (100%, mean score 3.210) and tortuosity (95.1%). Resveratrol significantly reduced both the incidence of TCDD-induced cleft palate to 18.4% and the degrees of renal pelvic and ureteric dilatations caused by TCDD. The results suggest that pretreatment with resveratrol might bring a beneficial outcome for reducing the incidence and severity of fetal malformations caused by TCDD exposure in utero.

Sleeve gastrectomy with wrapping using polytetrafluoroethylene to prevent gastric enlargement in a porcine model

BACKGROUND

The safety and efficacy of laparoscopic sleeve gastrectomy followed by biliopancreatic diversion with duodenal switch for morbid obesity has been well established. We previously recommended 2-stage laparoscopic biliopancreatic diversion with duodenal switch for super-super obese patients. In the 2-stage version, these patients undergo laparoscopic sleeve gastrectomy as a first-stage procedure, followed by laparoscopic biliopancreatic diversion with duodenal switch as the second stage for more definitive treatment of their obesity. However, short-term weight regain may occur owing to gastric dilation after initial laparoscopic sleeve gastrectomy. The aim of this study was to prevent gastric dilation after sleeve gastrectomy. We designed a sleeve gastrectomy with wrapping using polytetrafluoroethylene dual mesh.

METHODS

Eleven Yorkshire pigs weighing 20-25 kg underwent sleeve gastrectomy with wrapping using polytetrafluoroethylene dual mesh (wrapping group) or sleeve gastrectomy only (control group) to compare the weight loss. The animals were weighed weekly postoperatively. Necropsy was performed 8 weeks postoperatively to confirm the wrapping by pathologic report.

RESULTS

Four pigs died because of staple line failure or strangulation; no perioperative complications occurred in the other pigs. The operative time for the control group was 198 +/- 60 minutes and for the wrapping group was 181 +/- 86 minutes (P = NS). The average weight of the removed stomach was 123.3 +/- 5.8 g in the control group and 140.3 +/- 69.9 g in the wrapping group (P = NS). The postoperative weight gain at 8 weeks was significantly slower in the wrapping group than in the control group (P <.0001). The pathologic necropsy report noted that the mesh was well attached to the stomach wall at 9 days postoperatively, with no unexpected deaths.

CONCLUSION

Sleeve gastrectomy with wrapping using polytetrafluoroethylene dual mesh is feasible, and weight gain was reduced in the porcine model.

Minimization of risks of esophageal dilation

Esophageal dilation, along with many other therapeutic endoscopic procedures, carries with it an increased risk of complications, most of which are transient events but some of which may be catastrophic. The author reviews the literature concerning the major and minor complications that one will encounter in a busy and aggressive gastrointestinal endoscopic practice. There are scant prospective data concerning risk minimization and most studies are retrospective case series. Careful identification of groups of patients who have risk factors that may increase the potential for an adverse event is worthwhile and is reviewed. The current literature is discussed and suggestions to provide guidance and pearls in helping to avoiding and diagnosing major complications are given.

A modified Ross operation to prevent pulmonary autograft dilatation

A modification in Ross operation is described in which the free-standing pulmonary autograft root is suspended in a Dacron prosthetic vascular jacket with a view to prevent dilatation of the neo-aortic root. In a group of 13 patients operated consecutively using this technique, there was no significant increase in the diameters of the neo-aortic root after a mean 16-month follow-up. Aortic valve function remained also satisfactory.

Probability Model of the Inaccuracy of Residual Stromal Thickness Prediction to Reduce the Risk of Ectasia After LASIK Part I: Quantifying Individual Risk

PURPOSE

To measure the imprecision of microkeratome cuts, preoperative corneal pachymetry, and laser ablation depth and develop a statistical model to describe the probability of the residual stromal bed thickness (RST) after myopic LASIK being significantly thinner than predicted.

METHODS

Preoperative corneal thickness, flap thickness, ablation depth, and RST were measured in 36 eyes by a prototype three-dimensional very high-frequency (VHF) 50 MHz digital ultrasound scanning device (<1.2 microm precision), precursor to the commercially available Artemis 2. All eyes had undergone LASIK with the Moria LSK-One microkeratome and the NIDEK EC-5000 excimer laser. Based on the statistically combined uncertainty (standard deviation) and bias (accuracy to intended value) of corneal thickness measurement, flap thickness, and ablation depth, a continuous probability function was devised describing the chance of obtaining an actual RST less than a specified "cut-off". The model was applied using the data collected from the cohort of eyes. The model was also applied using published flap thickness statistics on a series of microkeratomes.

RESULTS

Precision (standard deviation) was 0.74 microm for VHF digital ultrasound measurement of pachymetry, 30.3 microm for Moria LSK-One flap thickness, and 11.2 microm for NIDEK EC-5000 ablation depth. Assuming negligible laser ablation depth bias, the model found the probability that the actual RST will be <200 pmicromgiven a target RST of 250 microm is 7.56% with the Moria LSK-One. The model applied to published flap statistics revealed a range of probabilities of leaving <200 microm given a target RST of 250 microm from <0.01% to 33.6%.

CONCLUSIONS

The choice of microkeratome, laser, and pachymeter has a significant impact on the variation of the depth of keratectomy and thus on the risk of ectasia. This model together with high-precision microkeratomes, preoperative pachymetry, and knowledge of laser ablation precision would enable surgeons to determine the specific imprecision of RST prediction for individual LASIK cases and minimize the risk of ectasia.

Probability Model of the Inaccuracy of Residual Stromal Thickness Prediction to Reduce the Risk of Ectasia After LASIK Part II: Quantifying Population Risk

PURPOSE

To derive a statistical model to estimate the rate of excessive keratectomy depth below a selected cut-off residual stromal thickness (RST) given a minimum target RST and specific Clinical Protocol; apply the model to estimate the RST below which ectasia appears likely to occur and back-calculate the safe minimum target RST that should be used given a specific Clinical Protocol.

METHODS

Myopia and corneal thickness distribution were modeled for a population of 5212 eyes that underwent LASIK. The probability distribution of predicted target RST error (Part I) was used to calculate the rate of excessive keratectomy depth for this series. All treatments were performed using the same Clinical Protocol; one surgeon, Moria LSK-One microkeratome, NIDEK EC-5000 excimer laser, Orbscan pachymetry, and a minimum target RST of 250 microm--the Vancouver Clinical Protocol. The model estimated the RST below which ectasia appears likely to occur and back-calculated the safe minimum target RST. These values were recalculated for a series of microkeratomes using published flap thickness statistics as well as for the Clinical Protocol of one of the authors-the London Clinical Protocol.

RESULTS

In the series of 5212 eyes, 6 (0.12%) cases of ectasia occurred. The model predicted an RST of 191 microm for ectasia to occur and that a minimum target RST of 329 microm would have reduced the -rate of ectasia to 1: 1,000,000 for the Vancouver Clinical Protocol. The model predicted that the choice of microkeratome varied the rate of ectasia between 0.01 and 11,623 eyes per million and the safe minimum target RST between 220 and 361 microm. The model predicted the rate of ectasia would have been 0.000003: 1,000,000 had the London Clinical Protocol been used for the Vancouver case series.

CONCLUSIONS

There appears to be no universally safe minimum target RST to assess suitability for LASIK largely due to the disparity in accuracy and reproducibility of microkeratome flap thickness. This model may be used as a tool to evaluate the risk of ectasia due to excessive keratectomy depth and help determine the minimum target RST given a particular Clinical Protocol.

Inhibition of Urokinase-Type Plasminogen Activator or Matrix Metalloproteinases Prevents Cardiac Injury and Dysfunction During Viral Myocarditis

Background— Acute viral myocarditis is an important cause of cardiac failure in young adults for which there is no effective treatment apart from general heart failure therapy. The present study tested the hypothesis that increased expression of the proteinases urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs) is implicated in cardiac inflammation, injury, and subsequent failure during Coxsackievirus-B3 (CVB3)–induced myocarditis.

Methods and Results— First, we showed increased expression and activity of uPA and MMP-9 in wild-type mice at 7 days of CVB3-induced myocarditis. Targeted deletion of uPA, which resulted in reduced MMP activity and cytokine expression or inhibition of MMPs by adenoviral gene overexpression of tissue inhibitor of metalloproteinases-1, decreased cardiac inflammation and reduced myocardial necrosis at 7 days and decreased cardiac fibrosis at 35 days after CVB3 infection. Importantly, loss of uPA or MMP activity prevented CVB3-induced cardiac dilatation and dysfunction, as determined by serial echocardiography.

Conclusions— Loss of uPA or MMP activity reduces the cardiac inflammatory response after CVB3 infection, thereby protecting against cardiac injury, dilatation, and failure during CVB3-induced myocarditis.

Laser in situ keratomileusis: ablation on the flap and stromal bed in a primary treatment

PURPOSE

To analyze outcomes of laser in situ keratomileusis (LASIK) performed on the flap and on the stromal bed at the same time in a primary treatment.

SETTING

Instituto de la Visión, Buenos Aires, Argentina.

METHODS

Twenty-two cases (13 female, 9 male) were studied retrospectively; the mean age of the patients was 33.15 years +/- 10.44 (SD). Inclusion criteria were low pachymetry or topographic asymmetry. Twenty cases (90.9%) presented with low pachymetry (512.2 +/- 21.40 mum), and 2 cases (9.1%) presented with topographic asymmetry (inferior-superior difference more than 1.5 diopters [D]). Ablation was performed on the flap from the back and on the bed. The flap was made using the Technolas Hansatome microkeratome and the ablation by the Technolas 217z excimer laser (both by Bausch & Lomb). Preoperatively, the spherical equivalent (SE) was -5.61 +/- 1.72 D, the cylinder was -1.78 +/- 1.24 D, and the best spectacle-corrected visual acuity (BSCVA) was 0.77 +/- 0.19. Difficulties and complications of the technique, efficacy and safety index, and aberrations were analyzed.

RESULTS

According to the surgical plan and our nomogram, diopters corrected on the flap were -1.73 +/- 1.08 and on the bed were -4.77 +/- 1.89. The mean follow-up was 8.28 +/- 2.19 months. At 6 months, the SE was -0.21 +/- 0.39, vectorial change was 1.69 +/- 0.74, and the BSCVA was 0.77 +/- 0.20. Postoperatively, no eye had an increase in refractive astigmatism. Uncorrected visual acuity was 20/40 or better in all cases (100%) and 20/25 or better in 13 cases (59.1%). Regarding gained and lost lines of BSCVA, 54.5% conserved the lines, 18.2% lost 1 line, 9.1% gained 1 line, and 18.2% gained 2 lines.

CONCLUSIONS

Simultaneous ablation on the flap and on the bed in cases of low pachymetry or topographical asymmetry was predictable, effective, and safe.

Technique for measuring laser in situ keratomileusis flap thickness using the IntraLase laser

Measurement of laser in situ keratomileusis flap thickness is required to estimate residual bed thickness. Historically, flap thickness has been assumed, estimated based on microkeratome head labeling, guessed based on flap handling characteristics, or calculated by subtraction pachymetry. We describe a method for measuring flap thickness before actual flap elevation using the IntraLase laser.

Prevention of Pouch Dilatation after Laparoscopic Adjustable Gastric Banding

BACKGROUND

The major long-term complication of laparoscopic adjustable gastric banding (LAGB) is dilatation of the gastric pouch, that is reported with a frequency ranging from 1 to 25%, and often requires removal of the band. In addition to the usual recommendations of bariatric surgery centers and dietetic advice to prevent this complication, over the last 4 years we introduced a technical modification of the procedure.

METHODS

From Nov 1993 to Dec 2004, 684 morbidly obese patients underwent adjustable gastric banding, 83 patients by open surgery and 601 patients by laparoscopy. The first 323 patients (group A) were operated by the perigastric approach, and 57 patients (group B) were operated by the pars flaccida approach. Since Dec 2000, 304 patients (group C) were operated with a modified pars flaccida technique, which consisted in suturing the gastric lesser curvature below the band with one or two stitches to the right phrenic crus to secure the band in place.

RESULTS

In group A, the most important late complication was irreversible dilatation of the gastric pouch, which occurred in 35 patients (10.8%), and required removal of the band in 30 cases and replacement in 5. In group B, there were 3 pouch dilatations (5.2%). In group C, only 4 dilatations occurred (1.31%), which required 3 band removals and 1 band replacement.

CONCLUSION

Dilatation of the gastric pouch appears to be dramatically reduced by our minor technical modification of band placement.

Modification to the Ross procedure to prevent autograft dilatation

Dilatation of the pulmonary autograft is a problem described following Ross procedure for aortic valve replacement. Patients at risk seem to be those with aortic insufficiency, bicuspid aortic valves, and those with aneurismal ascending aortas. We describe a technique for encasing the pulmonary autograft in a Dacron tube to prevent dilatation in these patients. This technique is reproducible and includes sewing the coronary arteries to all layers of the autograft and Dacron construct. Short-term follow-up shows excellent outcomes with respect to autograft valve function and lack of annular or sinotubular dilatation. This procedure may be useful for extending the Ross procedure to young adults, where autograft growth is no longer needed, to provide a non-dilatable neoaortic root.

Laparoscopic gastric bypass with silicone band in a pig model: prevention of anastomotic dilatation -- feasibility study

BACKGROUND

Morbid obesity has become a major global health problem. Surgery remains the only effective treatment for patients with severe obesity, because diet reduction methods and pharmacologic agents have not resulted in long-term weight reduction. Gastric bypass (GBP) can provide adequate weight loss, but after some years, dilatation of the gastric pouch and outlet may lead to weight regain by allowing the patient to increase food intake.

METHODS

2 groups of 6 pigs underwent laparoscopic GBP. In the first group, a non-adjustable silicone band (Proring-band, IOC, Innovative Obesity Care, Saint Etienne, France) was positioned 1 cm proximal to the gastrojejunal anastomosis. In the second group, the device used to stabilize the gastric pouch was an adjustable silicone band (Mid-band, Medical Innovation Developpement, Villeurbanne, France). Weight loss, complications and histological reaction were evaluated after 3 months.

RESULTS

Mortality rate was 25% (cardiac arrythmia in 2 pigs). Conversion rate was 25%. The positioning of the band was more difficult with the Mid-band because of its larger size and the presence of the catheter. The average weight change in the Proring group was 15.8 kg (3.5-25.1 kg), and in the Mid-band group was 12.0 kg (6.2-15.1 kg). Morbidity consisted of one intragastric migration of the Proring band into the gastrojejunal anastomosis, and one infection of the port in the Mid-band group treated by removal of the port and antibiotics.

CONCLUSION

Use of silicone devices may be safe and effective in the prevention of pouch or outlet dilatation after GBP.

Thin flap laser in situ keratomileusis: flap dimensions with the Moria LSK-One manual microkeratome using the 100-microm head

PURPOSE

To determine the predictability and consistency of corneal flap thickness, flap diameter, and hinge length with the modern 100 microm head of the Moria LSK-One manual microkeratome.

SETTING

Private clinic, office-based practice.

METHODS

Forty-two consecutive eyes with no previous surgery having thin flap laser in situ keratomileusis with the Moria LSK-One manual microkeratome had a new 100 microm (predicted flap thickness) head used for flap creation. Flap thickness was measured intraoperatively by subtraction ultrasound pachymetry (difference between central corneal thickness before flap cutting and residual stromal bed thickness after flap lifting). Vertical flap diameter and nasal hinge length were measured with calipers.

RESULTS

Mean flap thickness was 107 microm +/- 14 (SD) (range 82 to 137 microm). Standard deviation for mean vertical flap diameter was +/-0.24 mm. The cord length of the nasal hinge was variable with a mean of 4.26 +/- 0.63 mm (range 3.12 to 5.75 mm) in length. Postoperatively, there were no slipped flaps, flap striae, diffuse lamellar keratitis, or epithelial defects; there was 1 epithelial slide. At 1 day, the visual acuity was 20/20 or better in 76% of eyes.

CONCLUSIONS

The 100 microm head of the Moria LSK-One manual microkeratome cut a very predictable flap thickness and diameter but with variable length hinges. This flap thickness predictability was superior to that in other series with thicker intended flaps cut with mechanical microkeratomes and is comparable to that reported with the IntraLase FS femtosecond laser. Visual recovery was rapid, epithelial risks minimal, efficiency superior, and cost nominal relative to femtosecond laser technology.

Eine neue Behandlung der Keratektasie nach LASIK durch Kollagenvernetzung mit Riboflavin/UVA-Licht

BACKGROUND

Keratectasia is one of the most severe complications after refractive laser surgery. Usually penetrating keratoplasty is the treatment of choice to achieve an optical rehabilitation in such cases.

PATIENTS AND METHODS

We report on a female patient who developed keratectasia in both eyes 4 weeks after LASIK. Due to a severe keratectasia 10 months after LASIK, a treatment with riboflavin/UVA cross-linking was performed.

RESULTS

Due to the induced collagen cross-linking the biomechanical status of the cornea was stabilized and a progression of the keratectasia was prevented. The postoperative refraction and corneal topography have been stable for 18 months.

CONCLUSION

Collagen cross-linking leads to a stiffening of the anterior parts of the corneal stroma. The increase of biomechanical stability can stop the progression of a keratectasia after LASIK by means of a simple procedure.

[Ventilator associated acute lung injury]

Mechanical ventilation plays a central role in the critical care setting; but its use is closely related with some life threatening complications as nosocomial pneumonia and low cardiac performance. One of the most severe complications is called ventilator-associated lung injury (VALI) and it includes: Barotrauma, volutrauma, atelectrauma, biotrauma and oxygen-mediated toxic effects and it is related with an inflammatory response secondary to the stretching and recruitment process of alveoli within mechanical ventilation. The use of some protective ventilatory strategies has lowered the mortality rate 10% approximately.

Combined ICRS insertion and LASIK to maximize postoperative residual bed thickness in high myopia

PURPOSE

To describe a new technique and early outcomes of combined intrastromal corneal ring segment (ICRS) insertion and laser in situ keratomileusis (LASIK) to treat patients with moderate to high myopia and thin corneas.

SETTING

University-based academic practice, Boston, Massachusetts, USA.

METHODS

Combined ICRS insertion and LASIK was performed in 2 stages: ICRS channel formation (stage I) followed by LASIK and ICRS insertion (stage II).

RESULTS

Fifteen eyes of 11 patients with a mean preoperative spherical equivalent of -9.98 diopters (D) +/- 2.60 (SD) (range -7.13 to -16.25 D) and mean preoperative astigmatism of 1.11 +/- 0.75 D (range 0.00 to -3.00 D) were treated with combined ICRS insertion and LASIK. The mean central pachymetry was 526.13 +/- 35.69 microm (472 to 579 microm). The uncorrected visual acuity was 20/40 or better in 7 of 15 eyes (46.67%) at 1 month, 6 of 12 eyes (50.00%) at 3 months, 5 of 12 eyes (41.67%) at 6 months, and 6 of 12 eyes (50.00%) at 12 months. The best spectacle-corrected visual acuity was 20/40 or better at all times. Postoperative maps confirmed the absence of ectasia. The postoperative spherical equivalent was within +/-1.00 D of the intended refraction in 11 of 15 eyes (73.33%) at 1 month, 9 of 12 eyes at 3 and 6 months, and 8 of 12 eyes (66.67%) at 12 months.

CONCLUSIONS

Results of combined ICRS insertion and LASIK in moderately to highly myopic patients with relatively thin corneas were good. Long-term studies are needed to determine whether this procedure will decrease the risk of LASIK-induced keratectasia in these patients.

Photorefractive keratectomy versus laser in situ keratomileusis to prevent keratectasia after corneal ablation

A 27-year-old man had excimer photoastigmatic keratectomy in the right eye and laser in situ keratomileusis in the left eye for the treatment of equivalent myopia. Preoperative slitlamp examination did not reveal evidence of keratoconus, central corneal pachymetry was 485 microm in the right eye and 500 microm in the left eye, and corneal topography revealed asymmetric bow-tie astigmatism with inferior steepening in the right eye and a small area of inferior steepening in the left eye. Twenty-two months after surgery, the patient complained of poor vision in the left eye. Slitlamp examination of the left eye revealed central corneal thinning and protrusion, with a Fleischer ring within the flap. Corneal topographic evaluation revealed a stable map in the right eye and central corneal steepening indicative of keratectasia in the left eye.

l‐Arginine prevents impaired endothelium‐dependent cerebral arteriolar dilatation during acute infusion of nicotine

Exogenous treatment with L-arginine has been shown to restore impaired nitric oxide synthase (NOS)-dependent dilatation of peripheral blood vessels during disease states. We have shown that nicotine impairs NOS-dependent arteriolar dilatation in the cerebral circulation. However, the role of L-arginine in impaired responses of cerebral arterioles during infusion of nicotine has not been examined. Thus the goal of the present study was to examine the role of L-arginine in nicotine-induced impairment of cerebral arteriolar reactivity. We measured the diameter of pial arterioles in response to NOS-dependent (5'-adenosine diphosphate [ADP] and acetylcholine) and NOS-independent (nitroglycerin) agonists before and after infusion of vehicle or nicotine (2 microg/kg/min intravenously for 30 min followed by a maintenance dose of 0.35 microg/kg/min) in the absence or presence of L-arginine (10(-3) M). We found that topical application of L-arginine to cerebral microvessels during infusion of nicotine could prevent impaired NOS-dependent vasodilatation. We suggest that exogenous L-arginine may have a beneficial role in preventing cerebral microvascular dysfunction during exposure to nicotine.

Late aortic root dilatation in tetralogy of Fallot may be prevented by early repair in infancy

The objectives of this study were to examine the relative contributions of development and hemodynamics in aortic root dilatation of tetralogy of Fallot, to assess the impact of systemic to pulmonary artery shunt on aortic annular size, and to seek any relationship between the timing of corrective surgery and subsequent aortic root size. We performed a retrospective analytical study at a tertiary referral center of M-mode and two-dimensionol aortic root measurements in children with tetralogy of Fallot prior to any surgical or palliative intervention, after insertion of a surgical shunt, and on intermediate and long-term follow-up post-repair. The main outcome measures were aortic root diameter prior to correction, after palliative shunt insertion, and after definitive repair. The study found that the aortic root is enlarged in unrepaired tetralogy of Fallot irrespective of age, increased in the first 3-6 months after palliative shunt surgery, and persisted into adulthood in those repaired after 1 year of age. Age-corrected aortic root dimensions normalized by mid-childhood in those who were repaired in infancy. Preexisting aortic root dilatation normalizes by 7 years of age in patients with tetralogy of Fallot who have been repaired in infancy, whereas it persists into adulthood in the group repaired post-infancy.

Type 5 phosphodiesterase inhibition by sildenafil abrogates acute smoking-induced endothelial dysfunction

BACKGROUND

Endothelial dysfunction is a key early event in the process of atherosclerosis and a risk factor for cardiovascular events. Sildenafil, an effective oral treatment for patients with erectile dysfunction, inhibits cGMP degradation by specific type 5 phosphodiesterase (PDE) inhibition. Sildenafil has been shown to improve vascular function, however, the effect of type 5 PDE inhibition on acute smoking-induced endothelial dysfunction is unknown.

METHODS

We studied the effect of 50 mg of sildenafil on acute smoking-induced endothelial dysfunction in 14 male smokers according to a randomized, placebo-controlled, cross-over design. Endothelial function was evaluated with flow-mediated dilatation (FMD) of the brachial artery using high-resolution ultrasonography.

RESULTS

Sildenafil abolishes the decrease in FMD of the brachial artery that is induced acutely by smoking (placebo/smoking session: from 4.56% +/- 0.60% to 2.80% +/- 0.43%, sildenafil/smoking session: from 3.83% +/- 0.64% to 4.33% +/- 0.47%, ie, improvement of 51%, P < .05). This was associated with no reversal effect of sildenafil on smoking-induced decrease in resting brachial artery diameter and with a partial reversal of the smoking-induced decrease in hyperemic brachial artery diameter (placebo/smoking session: from 4.68 +/- 0.13 mm to 4.53 +/- 0.15 mm, sildenafil/smoking session: from 4.72 +/- 0.12 mm to 4.64 +/- 0.13 mm, ie, improvement of 1.5%, P < .005).

CONCLUSIONS

The present study shows, for the first time, that type 5 PDE inhibition with sildenafil abrogates the smoking-induced acute decrease in FMD of the brachial artery. These findings may have clinical implications given the detrimental consequences of smoking and the strategic role of normal endothelial function.

[Tegaserod inhibits noxious rectal distention induced response and spinal nNOS expression in rats with visceral hypersensitivity]

OBJECTIVE

To examine the effects of 5-HT4 receptor partial agonist tegaserod on response to rectal distention (RD) and on nNOS expression in spinal cord, and to investigate the mechanism of tegaserod influencing visceral sensation.

METHODS

Neonatal SD rats randomLy received colonic irritation by acetic acid from postnatal day 8 to day 21 as visceral hypersensitive model (Group H); or by saline intrarectally as control group (Group C). Five subgroups of Group H were i.p. injected randomLy with saline, vehicle (1-methyl-2-thpyrrolidone) or tegaserod at doses of 0.1, 0.3 and 1.0 mg/kg, respectively. Two subgroups of Group C were i.p. injected with saline or tegaserod at dose of 1.0 mg/kg. Ten minutes after injection rectal distention was performed, AWR was recorded and nNOS expression in spinal cord (L6-S1) was analyzed quantitatively by NADPH-diaphorase histochemistry.

RESULTS

Tegaserod significantly inhibited AWR in Group H, but had no effect in Group C. Tegaserod (1.0 mg/kg) inhibited AWR more significantly in Group H than in Group C at the largest volume of distention (1.2 mL). In Group H, tegaserod (1.0 mg/kg) significantly decreased overall nNOS positive cells in spinal cord to 40% of saline. The greatest attenuation was in dorsal horn (31% of H-saline). Tegaserod (0.1 mg/kg) did not affect the overall nNOS(P>0.20), but decreased the number of nNOS positive cells in central canal (79% of H-saline P<0.01).

CONCLUSION

Tegaserod inhibits response to rectal distention in rats with visceral hypersensitivity and dose dependently attenuates spinal nNOS expression, especially in dorsal horn and central canal. nNOS may be involved in the modulation of visceral sensitivity by tegaserod.

Keratoconus Fittings

PURPOSE

To examine the relative merits of apical support and apical clearance fitting of rigid gas-permeable contact lenses for keratoconus.

METHODS

After an historic review of fitting approaches for keratoconus, a case report is described in which an adventitious apical clearance fitting for early keratoconus might have been associated with accelerated progress of the ectasia.

DISCUSSION

The hypothesis that apical clearance fittings increase the risk of accelerating ectasia progression in early keratoconus is examined in counterpoint to the hypothesis that apical support fittings increase the risk of apical scarring. Reference is made to the responses of normal corneas to apical clearance fitting and to apical contact fittings used in orthokeratology fittings. The tendency for corneas to mold to contact lens curvature is reviewed. The possibility that reduced corneal thickness or tissue softening and associated changes to the biomechanical properties of the cornea in keratoconus may facilitate molding with apical clearance fitting is examined.

CONCLUSIONS

Known and putative risk factors for fitting complications that are associated with apical clearance and apical touch contact lens fitting are given as a basis for the reader to draw conclusions about the management of contact lens fitting for keratoconus. The possibility of symptomless adverse responses is a strong indication for frequent routine aftercare reviews.

Heart rate reduction by zatebradine reduces infarct size and mortality but promotes remodeling in rats with experimental myocardial infarction

The importance of heart rate for left ventricular remodeling and prognosis after myocardial infarction is not known. We examined the contribution of heart rate reduction by zatebradine, a direct sinus node inhibitor without negative inotropic effects on left ventricular function and dilatation, on mortality, energy metabolism, and neurohormonal changes in rats with experimental myocardial infarction (MI). Thirty minutes after left coronary artery ligation or sham operation, the rats were randomized to receive either placebo or zatebradine (100 mg·kg–1·day–1per gavage) continued for 8 wk. Mortality during 8 wk was 33.3% in the placebo and 23.0% in the zatebradine group ( P < 0.05); MI size was 36 ± 2% and 30 ± 1% (means ± SE, P < 0.05), respectively. Zatebradine improved stroke volume index in all treated rats but increased left ventricular volume in rats with small MI (2.43 ± 0.10 vs. 1.81 ± 0.10 ml/kg, P < 0.05) but not in rats with large MI (2.34 ± 0.09 vs. 2.35 ± 0.11 ml/kg, not significant). Zatebradine reduced left and right ventricular norepinephrine and increased left and right ventricular 3,4-dihydroxyphenyl ethylene glycol-to-norepinephrine ratio suggesting aggravation of cardiac sympathetic activation by zatebradine after MI. Creatine kinase and lactate dehydrogenase isoenzymes in rats with MI remained unchanged by zatebradine. Lowering heart rate per se reduces mortality and MI size in this model but induces adverse effects on left ventricular remodeling in rats with small MI.

[Short-acting beta 1-adrenergic blocker is useful for anesthetic management of cesarean section in a patient with Marfan syndrome]

The aortic root dilatation and its dissection are the most catastrophic events in pregnancy with Marfan syndrome as has been reported. It has been shown that prophylactic beta-adrenergic blocker is effective in reducing the aortic distensibility. However, its fetal toxicity should be considered. It includes hypoglycemia, neonatal apnea and bradycardia. Landiolol hydrochloride is a new beta-adrenergic blocker of which greatest advantages are its short duration of action, rapid clearance and high beta 1-selectivity. This drug has not been evaluated in its maternal and fetal effects on human pregnancy. We report a case of Marfan syndrome complicated with 49 mm annuloaortic ectasia. She received landiolol for the prevention of aggravated aortic root dilatation during cesarean section. After the administration of spinal anesthesia, she was treated with landiolol by continuous infusion at a rate of 0.003 to 0.005 mg.kg-1.min-1 until delivery of 1764 g infant with Apgar scores of 5 (1 min) and 8 (5 min). We could maintain maternal hemodynamics stable and good post cesarean uterus contraction. No severe adverse effects were observed in the infant. In conclusion, it is useful for maintaining the hemodynamics stable in a pregnant woman with Marfan syndrome and keep the infant safe from any adverse effects by infusing of landiolol.

Effect of Suturing on Iatrogenic Keratectasia After Laser in situ Keratomileusis

PURPOSE

To evaluate the influence of corneal suturing on the clinical course of iatrogenic keratectasia after laser in situ keratomileusis (LASIK), in order to improve quality of vision and to avoid progressive deterioration of visual acuity.

METHODS

Three patients (four eyes) who had a perforation during LASIK or became keratectatic after LASIK received corneal suturing with 10-0 nylon immediately or up to 11 days after LASIK. Sutures were left in place for 1 to 4 months. Patients were followed for 20 to 23 months after suturing.

RESULTS

All eyes had a significant improvement in uncorrected and best spectacle-corrected visual acuity after suturing. The improvements in visual acuity for all patients remained unchanged after suture removal. In patient 1, keratectatic changes were not detected in the sutured eye although they were detected in the contralateral unsutured eye. In patient 2, both eyes were sutured, one immediately and the other 11 days after LASIK; no keratectatic changes were noted in either eye. Slight progression of corneal protrusion was observed in patient 3, who had corneal suturing after development of prominent keratectasia 2 weeks after LASIK. This eye showed stable but moderate keratectatic change 9 months after suture removal.

CONCLUSIONS

Flap suturing in patients during the course of keratectasia after LASIK improved both aided and unaided visual acuity. Prompt suturing seemed to provide a means of preventive management for iatrogenic keratectasia in anticipation of keratoplasty.

Modified ross procedure for dysplasic ascending aorta

We present a modification of the Ross procedure, to help reduce the risk of late pulmonary artery wall dilatation. The strength of this modified technique is its composite graft construction, consisting of a pulmonary valve autograft inserted in a Dacron tube. This composite graft can be used either as a free graft or a mini-root implant.

Failure to prevent progressive dilation of ascending aorta by aortic valve replacement in patients with bicuspid aortic valve: comparison with tricuspid aortic valve

BACKGROUND

Patients with bicuspid aortic valve (BAV) have been frequently complicated with ascending aortic dilation possibly because of hemodynamic burdens by aortic stenosis (AS) or regurgitation (AR) or congenital fragility of the aortic wall.

METHODS AND RESULTS

To clarify if the aortic dilation could be prevented by aortic valve replacement (AVR) in BAV patients, we studied 13 BAV (8 AR dominant, 5 AS dominant) and 14 tricuspid aortic valve (TAV) patients (7 AR, 7 AS) by echocardiography before and after AVR (9.7+/-4.8 years). We also studied 18 BAV (11 AR, 7 AS) without AVR. Diameters of the sinuses of Valsalva, sinotubular junction and the proximal aorta were measured. The annual dilation rate was calculated by dividing changes of diameters during the follow-up period by the body surface area and the observation interval. We found that aortic dilation in BAV patients tended to be faster than that in TAV patients, although a significant difference was found only at the proximal aorta (0.18+/-0.08 versus -0.08+/-0.08 mm/(m2/year), P=0.03). BAV patients with and without AVR showed similar progressive dilation. AR dominant group showed tendency of more progressive dilation than AS dominant group in BAV, although it did not reach statistical significance. TAV patients did not show further aortic dilation after AVR.

CONCLUSIONS

AVR could not prevent progressive aortic dilation in BAV. Since the aorta did not dilate in TAV, progressive aortic dilation in BAV seems mainly due to the fragility of the aortic wall rather than hemodynamic factors.

Unexpected flap thickness in laser in situ keratomileusis

We report a case of an unexpected thick flap during laser in situ keratomileusis (LASIK) that led to abandonment of surgery. This report illustrates the importance of stromal bed measurements after flap creation in LASIK. A thicker-than-expected flap can lead to a thinner-than-anticipated residual cornea and subsequent ectasia or even perforation during laser ablation. It is possible that reports of ectasia in normal thickness corneas reflect thicker-than-anticipated flaps.

Six-year follow-up of laser in situ keratomileusis for moderate and extreme myopia using a first-generation excimer laser and microkeratome

PURPOSE

To evaluate objectively and subjectively the long-term outcome of laser in situ keratomileusis (LASIK) in patients with high and very high myopia.

SETTING

Department of Ophthalmology, Philipps University, Marburg, Germany.

METHODS

Thirty-three eyes of 19 patients were followed for a mean of 76 months (range 50 to 84 months) after primary LASIK using the Keratom I excimer laser (Schwind) and the ALK microkeratome (Chiron). Refraction, glare, pachymetry, corneal topography, and tear-film secretion and stability were measured. At the last examination, patients also answered a 14-item questionnaire.

RESULTS

Preoperatively, the mean spherical equivalent was -13.65 diopters (D). At 1 year, it was -0.25 D and after 6 years, -0.88 D. Fifteen percent of eyes lost > or =2 lines of best spectacle-corrected visual acuity (BSCVA), and 9% gained > or =2 Snellen lines. At the end of the study, 46% of eyes were within +/-1.0 D of the attempted corrected and 88% were within +/-3.0 D. There were 5 microkeratome-associated complications; 3 resulted in loss of BSCVA. The latest pachymetry showed a mean corneal thickness of 498.5 microm (range 396 to 552 microm). There were no cases of keratectasia. Seventy-five percent of patients noted an increase in their quality of life. Seventy-one percent were satisfied with their postoperative visual acuity; however, 75% noticed glare and halos at night.

CONCLUSIONS

Laser in situ keratomileusis correction of very high myopia did not cause keratectasia in the long term provided the corneal thickness was respected. A flap thickness setting of 130 microm with a first-generation microkeratome resulted in a high number of cut failures. Most patients were happy with the results despite a modest level of accuracy and glare.

How to exclude the dilated false lumen in patients after a type B aortic dissection? The cork in the bottleneck

PURPOSE

To report techniques for excluding the dilated false lumen associated with chronic type B aortic dissection following placement of a stent-graft in the true lumen.

CASE REPORTS

Two patients underwent stent-graft implantation for a dilated false lumen after chronic aortic dissection, but the false lumen was not excluded from the circulation by this procedure. The false lumen was obliterated in one case with Greenfield filters and detachable balloons placed above a renal artery orifice that was perfused via the false lumen. This acted like "a cork in the bottleneck" to block retrograde flow into the thoracic portion of the false lumen above the blockade. In the other patient, an occluder device was used as the "cork." In both cases, a good result was obtained. The occluder device is preferred because deployment is more controllable.

CONCLUSIONS

An occluder device may be used like a cork in a bottle to exclude the dilated false lumen in the thoracic aorta after a type B dissection.

Taking posterior rectus sheath laparoscopically to reinforce the gastrojejunostomy in laparoscopic Roux-en-Y gastric bypass

BACKGROUND

The Roux-en-Y gastric bypass (RYGBP) is now performed laparoscopically widely with low morbidity and mortality. However, in some cases long-term adequate weight loss is not satisfied because of dilatation of the gastrojejunostomy. Therefore, a prosthetic material and bio-membranes have been used to prevent dilatation. In this study, we used posterior rectus sheath by laparoscopy, to evaluate feasibility and safety of the procedure.

METHODS

20 Yorkshire pigs, under general anesthesia, had a standard laparoscopic RYGBP. In addition, 10 had their gastrojejunostomy anastomosis wrapped with 2x10 cm posterior rectus sheath. Clinical and operative outcome after operation were compared with the control group of laparoscopic RYGBP cases.

RESULTS

The median weight of the pigs was 46.1 kg (range 42-51) in the posterior rectus sheath-applied group and 45.2 kg (range 42-49) in the control group. All gastrojejunostomies in the posterior rectus sheath-applied group were successfully reinforced laparoscopically. Both groups loss weight compared with their normal growth weight, but there was no significant difference in the median weight loss between the two groups. Two pigs in the posterior rectus sheath-applied group developed a stenosis at the gastrojejunostomy anastomosis following RYGBP. All pigs in the posterior rectus sheath-applied group were found to develop hypertrophic smooth muscle and connective tissue scarring at the gastrojejunostomy on histologic examination.

CONCLUSION

Laparoscopic application of posterior rectus sheath around the gastrojejunostomy in laparoscopic RYGBP is feasible and safe. The sheath-applied group developed stenosis and connective tissue scarring. Additional research is needed to evaluate effectiveness in preventing dilation of the anastomosis.

Surgical approach to ascending aorta in bicuspid aortic valve

OBJECTIVE

Former studies have pointed out that hemodynamic stress imposed by associated valvular disease is the primary factor in the development of ascending aorta dilatation. At present, intrinsic wall pathology is blamed for dilatation and aneurysm formation in bicuspid aortic valve (BAV).

MATERIALS AND METHODS

Aortic valve replacement (AVR) was performed on 78 adult patients with BAV. Patients were divided into two groups. Group I (n = 27) underwent only AVR. Group II (n = 51) underwent AVR and additional ascending aorta procedures such as Shawl-Lapel aortoplasty (n = 12) and tailoring aortoplasty (n = 9). Dacron wrapping was performed after both techniques were done. Ascending aorta replacement was done on 11 patients by using composite graft. Supracoronary graft replacement was performed in 3 patients after AVR.

RESULTS

Ascending aorta diameter increment was 1.25 mm/year in normotensive and 2.80 mm/ year in hypertensive patients. Ascending aorta aneurysm (diameter > 55 mm) developed in eight patients in the postoperative period in group I. Ascending aorta dilatation did not develop in group II patients. Mean survival time +/- standard error (SE) was 128 +/- 11 and 99 +/- 4 months and survival possibility was 77.78% and 92.16%. Freedom from reoperation was 65.4% and 95.9% in 8 years in group I and group II, respectively.

CONCLUSION

Aortic wrapping with or without aortoplasty has a beneficial effect not only in dilated ascending aorta but also in all nondilated BAV patients with normal-sized aortic diameter. Ascending aorta wrapping in BAV patients preserves the endothelial lining and prevents further dilatation, aneurysm formation, and dissection.

Myocardial infarct expansion and matrix metalloproteinase inhibition

BACKGROUND

A potential mechanism for left ventricular (LV) remodeling after myocardial infarction (MI) is activation of the matrix metalloproteinases (MMPs). This study examined the effects of MMP inhibition (MMPi) on regional LV geometry and MMP levels after MI.

METHODS AND RESULTS

In pigs instrumented with radiopaque markers to measure regional myocardial geometry, MI was created by ligating the obtuse marginals of the circumflex artery. In the first study, pigs were randomized to MMPi (n=7; PD166793, 20 mg x kg(-1) x d(-1)) or MI only (n=7) at 5 days after MI, and measurements were performed at 2 weeks. Regional MI areas were equivalent at randomization and were increased in the MI-only group at 2 weeks after MI compared with the MMPi group. In the second study, pigs randomized to MMPi (n=9) or MI only (n=8) were serially followed up for 8 weeks. At 8 weeks after MI, LV end-diastolic dimension was lower with MMPi than in the MI-only group (4.7+/-0.1 versus 5.1+/-0.1 cm, P<0.05). Regional MI area was reduced with MMPi at 8 weeks after MI (1.3+/-0.1 versus 1.7+/-0.1 cm2, P<0.05). MMPi reduced ex vivo MMP proteolytic activity. In the MI region, membrane-type MMP levels were normalized and levels of the endogenous tissue inhibitor of MMPs (TIMP-1) were increased compared with normal levels with MMPi. These effects were not observed in the MI-only group.

CONCLUSIONS

MMPi attenuated the degree of post-MI LV dilation and expansion of the infarct during the late phase of MI healing. In addition, exogenous MMPi caused region-specific modulation of certain MMP and TIMP species.

Cryopreservation prevents arterial allograft dilation

Historically, immune-mediated degradation and subsequent aneurysm formation have limited the usefulness of cryopreserved arterial allografts. This study tested the hypothesis that modern cryopreserved arterial allografts are protected from immune-mediated dilation. Abdominal aortas were harvested from anesthetized rats (Lewis and Brown-Norway) for immediate implantation or cryopreservation. Subsequently, Lewis rats underwent infrarenal aortic replacement with either an acutely harvested or a cryopreserved graft. There were four experimental groups: (1) acutely harvested isografts (Iso; n = 6), (2) cryopreserved isografts (C-Iso; n = 6), (3) cryopreserved allografts (C-Allo; n = 6), and (4) acutely harvested allografts (Allo; n = 6). All grafts were explanted at 8 weeks. A video camera and edge detection software were used to measure systolic and diastolic in vivo graft diameter (d). Measurement of arterial blood pressure (p) allowed calculation of compliance (Dd/Dp). Tail-cuff plethysmography was used to assess graft patency at 1 week. Graft diameter and blood pressure measurements were repeated at harvest. All harvested grafts were examined histologically. Our results showed that cryopreservation prevented immune-mediated dilation in arterial allografts in our 8-week rat implant model. Furthermore, the compliance of the cryopreserved grafts and was similar to that of controls. Further investigation is needed to delineate the exact mechanism of these potential clinically significant findings.

Progressive aortic root dilatation in adults late after repair of tetralogy of Fallot

BACKGROUND

Aortic valve or aortic root (AoRo) replacement is occasionally required because of AoRo dilatation and aortic regurgitation (AR) in repaired tetralogy of Fallot (TOF). We evaluated AoRo size and possible factors associated with its dynamic nature in adults with repaired TOF.

METHODS AND RESULTS

Of 216 patients with TOF repair who underwent echocardiography in 1997, we identified 32 patients (mean age, 36+/-8.0 years) with AoRo dilatation, defined as ratio of observed to expected AoRo size by standard nomogram >1.5 (group A), and 54 TOF controls, matched for age with AoRo ratio <1.5 (group B), who underwent at least 1 previous echocardiogram in the preceding 10 years. Mean indexed AoRo size (cm/m2) in 1997 was 2.5+/-0.5 in group A and 1.7+/-0.2 in group B (P<0.0001). AoRo rate of change (mm/year) from the first to 1997 study (mean interval, 5.2+/-3.8 years) was 1.7+/-3.8 in group A and 0.03+/-1.6 in group B (P=0.001). Patients from group A had a longer shunt-to-repair interval (P=0.048) with a higher prevalence of pulmonary atresia (P<0.0001), right aortic arch (P=0.03), moderate to severe AR (P=0.002), aortic valve replacement (P=0.02), larger cardiothoracic ratio (P=0.02), and increased left ventricular end-diastolic dimensions (P=0.002).

CONCLUSIONS

A subset of adult TOF exhibits ongoing dilatation of AoRo late after repair. This dilatation relates to previous long-standing volume overload of AoRo and possibly to intrinsic properties of AoRo and may lead to AR. Meticulous follow-up of AoRo after TOF repair is recommended.

Comparison of time of reperfusion during anterior wall acute myocardial infarction to left ventricular volume one month and 20 months later

We studied 95 patients with a first anterior wall acute myocardial infarction who received successful reperfusion within 72 hours after the onset. The patients were divided into 4 groups based on the time required to achieve reperfusion; <3 hours (n = 23), 3 to 6 hours (n = 42), 6 to 24 hours (n = 17), and >24 to 72 hours (n = 13). The infarct size, as evaluated by thallium-201 single-photon emission computed tomography, at 1 month after the infarct was significantly larger (p <0.05) in >24 to 72 hours (1,593 +/- 652 U) than that in <3 hours (749 +/- 650 U), but was not significantly different from that at 3 to 6 hours (1,353 +/- 770 U) or 6 to 24 hours (1,371 +/- 561 U). The end-diastolic volume index at 1 month did not differ among the 4 groups. However, the end-diastolic volume index during the follow-up period (20 +/- 8 months) in >24 to 72 hours (93 +/- 23 ml/m(2)) was significantly larger than that in the other 3 groups (<3 hours [65 +/- 21 ml/m(2)], 3 to 6 hours [65 +/- 22 ml/m(2)], and 6 to 24 hours [70 +/- 25 ml/m(2)]). Similar findings were observed in end-systolic volume index. In conclusion, although infarct size reduction was not observed by late reperfusion, left ventricular volumes at 1 month were comparable among patients with successful reperfusion within 3 and up to >24 hours. Left ventricular volumes 2 years after acute myocardial infarction were significantly larger in patients who did not under reperfusion for >24 hours.