Genu Valgum in Pediatric Patients Presenting With Patellofemoral Instability

BACKGROUND

Lower extremity valgus is a commonly described factor associated with patellofemoral instability (PFI) and, if identified before skeletal maturity, can be treated with guided growth. The prevalence of valgus alignment in the pediatric and adolescent PFI population is largely unknown.

PURPOSE

The aim of this study was to report the prevalence of valgus alignment in adolescent patients presenting with PFI; with secondary assessment of high-grade valgus (zone II or III), coronal asymmetry, and associations of these findings with body mass index (BMI).

STUDY DESIGN

A retrospective cohort study.

METHODS

A total of 279 consecutive patients (349 knees) with a diagnosis of PFI presenting to a single orthopedic pediatric sport medicine surgeon were identified. A retrospective chart review was performed to collect demographic and clinical data, chronologic and bone age, sex, BMI, mechanism of injury, and the presence of osteochondral fracture. Full-length standing hip-to-ankle alignment radiographs were graded for knee alignment mechanical zone utilizing standard linear femoral head center to talar center assessment. In addition, mechanical axis deviation, mechanical lateral distal femoral angle and medial proximal tibial angle (MPTA) were also calculated.

RESULTS

Mean patient age was 14.0±2.5 years. There were 162 (58.1%) females and mean BMI was 24.3±6.4. Seventy patients (25.1%) had bilateral PFI. Standing alignment radiographs were available for 81.4% of knees (n=284). Valgus alignment was present in 172 knees with PFI (60.6%). High-grade valgus, defined as zone 2 or greater, was present in 66 knees (23.3%). Overall, 48.9% had asymmetry of coronal alignment (n=139). The mean mechanical lateral distal femoral angle was 85.4±2.8 and the mean MPTA was 88.2±2.6. There was a greater MPTA in female patients (88.8±2.4 vs. 87.5±2.7, P <0.001). A higher BMI (24.87±6.95, P =0.03) was associated with valgus alignment.

CONCLUSIONS

There is a high (60%) prevalence of lower extremity valgus in adolescent patients presenting with PFI, with nearly 1 in 4 presenting with high-grade valgus. The treatment team should be aware of this association as it may be an important consideration in the pediatric and adolescent PFI populations.

LEVEL OF EVIDENCE

Level III.

Soft Tissue Cam Impingement in Adolescents: MRI Reveals Impingement Lesions Underappreciated on Radiographs

BACKGROUND

Femoroacetabular impingement (FAI) has been described as repetitive and abnormal contact between a structurally abnormal proximal femur (cam) and/or acetabulum (pincer), occurring during the terminal range of motion of the hip. While cam and pincer lesions have traditionally been defined as osseous abnormalities, there may be a subset of adolescent patients whose impingement is primarily soft tissue (nonosseous). The existence of a nonosseous cam lesion in adolescents with FAI has not been well described.

PURPOSE

To identify and characterize a series of adolescent patients with nonosseous (soft cam) FAI identified on magnetic resonance imaging (MRI) and compare these patients' clinical presentation and outcome with those of a cohort with primary osseous cam FAI in the same age group.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A prospective institutional registry of patients with symptomatic FAI was reviewed. Patients were included if they had an MRI scan and a lateral radiograph of the hip (45° Dunn or frog) at a baseline visit. On MRI, the anterolateral femoral head was evaluated using radial, coronal, sagittal, or axial oblique sequences. A soft cam lesion was identified by the presence of soft tissue thickening of ≥2 mm at the anterolateral femoral head-neck junction. An alpha angle was measured on MRI scans and radiographs when a lesion was identified. The cohort with soft cam lesions was reviewed and findings and outcomes were compared with those of a cohort with osseous cam lesions. Continuous variables were first examined for normality, and then nonparametric tests-such as the Kruskal-Wallis test-were considered. The change between pre- and postoperative patient-reported outcomes (PROs) was described by mean and standard deviation and evaluated with an independent-samples t test.

RESULTS

A total of 31 (9.3%) of 332 hips (mean age, 16.4 years [range 13.1-19.6 years]; women, 83.9%) were identified with a soft tissue impingment lesion on MRI at the femoral head-neck junction between the 12 and 3 o'clock positions. These lesions demonstrated a thickened perichondral ring (71%), periosteal thickening (26%), or a cartilaginous epiphyseal extension (3%). The mean alpha angle on MRI was greater than on radiographs (63.5°± 7.9° vs 51.3°± 7.9°; P < .0001). A total of 22 patients (71%) with soft impingement underwent hip preservation surgery. When compared with patients in the osseous cohort who also underwent surgical management, both groups showed similar significant improvements from pre- to postoperatively (soft: modified Harris Hip Score [mHHS], 26.9 ± 18.2; Hip disability and Osteoarthritis Outcome Score [HOOS], 31.4 ± 22.9; osseous: mHHS, 22.8 ± 20.8; HOOS, 27.4 ± 20.1; P < .0001), with a mean follow-up of 3.4 years (range, 1-7 years) in the soft cam cohort and 3 years (1-10.1 years) in the osseous cam cohort.

CONCLUSION

Clinicians should be aware of nonosseous or soft cam lesions that cause impingement in adolescent patients without an obvious osseous cam on radiographs. MRI is required to detect these soft cam lesions. When nonoperative treatment fails, the PROs in these patients after operative management are comparable with those in patients with osseous cam lesions. Further research is needed to determine whether the soft cam precedes an osseous cam or whether it is a separate entity.

Suture-Bridge Fixation of Osteochondral Fractures and Osteochondritis Dissecans in the Knee: Excellent Rates of Early Lesion Stability and Osseous Union

BACKGROUND

Preservation of articular cartilage in the setting of acute or chronic injury in the adolescent and young adult knee is paramount for long-term joint health. Achieving osseous union, minimizing implant-related injury, and eliminating the need for reoperation for traumatic chondral and osteochondral lesions (OCLs) and osteochondritis dissecans (OCD) remain a challenge for the orthopaedic surgeon.

PURPOSE

To evaluate radiographic healing, patient-reported outcomes, and short-term complications after suture-bridge fixation of chondral fragments, osteochondral fractures, and OCD lesions in the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study included consecutive patients (38 patients, 40 knees) treated within a single academic sports medicine institution who underwent suture-bridge fixation of an OCL or an OCD lesion of the knee from initiation of the technique in October 2019 through March 2021. The suture-bridge technique entailed bioabsorbable knotless anchors placed on the outside margins of the lesion with multiple strands of hand-tensioned absorbable (No. 0 or No. 1 Vicryl) or nonabsorbable (1.3-mm braided polyester tape) bridging suture. Healing was assessed by radiography and magnetic resonance imaging (MRI), with MRI scans obtained on all OCD lesions and any chondral-only lesions. MRI scans were available for 33 of 40 (82.5%) knees within 1 year of surgery and were evaluated for lesion healing. Complications and rates and timing of return to sport were evaluated. Patient-reported outcomes in the OCD cohort were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) to determine early pain and functional improvement.

RESULTS

In total, 33 (82.5%) lesions demonstrated full union, and no lesions failed treatment. MRI assessment of healing (mean, 5.8 months; range, 3-12 months) demonstrated 9 (64.3%) OCD lesions with full union, 5 (35.7%) OCD lesions with stable union, and no OCD lesions with nonunion. Of the OCLs, 17 (89.5%) had full union, 2 (10.5%) had stable union, and none had nonunion. The 7 bony OCLs without an MRI scan demonstrated complete radiographic union. In 30 (75.0%) lesions, patients returned to sports at a mean of 6.5 months (range, 3.8-10.2 months). KOOS Activities of Daily Living, Pain, Quality of Life, and Symptoms scores demonstrated significant improvement from baseline at 6 months and at 1 year. There were 2 (5%) complications, consisting of reoperation for marginal chondroplasty on an otherwise stable lesion, and re-operation for intial un-treated patellar instability, with no reoperations for failure or revision of the suture-bridge construct.

CONCLUSION

In this series of OCLs and OCD lesions of the knee, suture-bridge fixation demonstrated excellent rates of MRI and radiographic union and good early outcomes with minimal short-term complications. This technique may be used for lesion salvage as an alternative to metallic and nonmetallic screw/tack constructs in the treatment of these challenging lesions. Longer term follow-up and investigation are warranted.

Radiographic Predictors of Reoperation in Adolescents Undergoing Hip Preservation Surgery for Femoroacetabular Impingement

BACKGROUND

Femoroacetabular impingement (FAI) is a condition caused by repetitive abutment of a morphologically abnormal proximal femur and/or acetabulum that may result in chondral and labral pathology. An understanding of radiographic parameters associated with successful primary surgery has not been well established.

PURPOSE

To determine preoperative radiographic parameters that predict reoperation for FAI and correlate radiographic measurements with outcomes in these patients.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A prospectively collected institutional registry of adolescent patients (age, <19 years) who underwent surgery for FAI (arthroscopic/open) was reviewed. Preoperative standing anteroposterior pelvic radiographs were analyzed for femoroepiphyseal acetabular roof (FEAR) index, as well as lateral center-edge angle (LCEA) and alpha, Tönnis, and Sharp angles. Patient-reported outcomes (PROs) (modified Harris Hip Score, Hip disability and Osteoarthritis Outcome Score) were analyzed preoperatively and at 1- and 2-year followup. Radiographic indication of risk for reoperation was evaluated using receiver operating characteristic (ROC) analysis. Spearman correlation was calculated between radiographic measurements and PROs at 2 years postoperatively.

RESULTS

A total of 81 patients (91 hips) underwent primary surgery (57 surgical dislocations vs 34 arthroscopies) for FAI. The mean age at time of primary operation was 16.23 years (range, 10.4-19.6 years) (73.6% female). Eleven hips (12.1%) underwent reoperation at a mean of 20.6 months from primary surgery. The LCEA, FEAR index, Tönnis angle, and Sharp angle before index surgery were significantly different (P < .05) between patients who underwent reoperation and those who did not. ROC analysis indicated that LCEA <22°, FEAR index >-8.7°, Tönnis angle >6.0°, and Sharp angle >44° were predictors for increased risk of reoperation. Using the cutoff values from the ROC analysis in this series, 43% of patients with an LCEA ≤22° had a repeat procedure, while only 8% of those with an LCEA >22° had a repeat procedure. Similar trends were seen with the other aforementioned acetabular radiographic measurements (FEAR index, Tönnis angle, Sharp angle). Patients who did not require a reoperation demonstrated significant improvement in all PRO categories from their preoperative to 2-year postoperative visits (P < .0001).

CONCLUSION

In patients undergoing treatment for FAI, a reoperation was associated with radiographic signs of hip dysplasia, indicating that patients with a shallower acetabulum are at risk for a repeat operation.

An Activity Scale for All Youth Athletes? Clinical Considerations for the HSS Pedi-FABS

Background

The Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) has demonstrated normally distributed scores in children aged 10 to 18 years. It has been used to evaluate knee injuries; however, there is limited information regarding its use in evaluating other injury types.

Purpose

To (1) assess the validity and utility of HSS Pedi-FABS in youth athletes with injuries to different parts of the body and (2) evaluate the association between the HSS Pedi-FABS and the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Global Health 7 (PGH), as well as PROMIS-Pain Interference (PGH-PI) and PROMIS-Fatigue (PGH-F) components.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

The authors performed a retrospective review of youth athletes aged 10 to 18 years who completed the HSS Pedi-FABS as part of their previsit intake questionnaire between April 2016 and July 2020. HSS Pedi-FABS score distributions were compared and evaluated for ceiling effects in cohorts determined by demographic, injury characteristic, and sports participation variables; a ceiling effect was determined to be present if >15% of respondents received the highest possible score. HSS Pedi-FABS scores were analyzed for a correlation with PGH, PGH-PI, and PGH-F components.

Results

Included were 2274 patients (mean age, 14.6 ± 2.1 years; 53.0% female) participating in 21 distinct primary sports for 9.6 ± 7.9 hours per week. The mean HSS Pedi-FABS scores by injury group were as follows: elbow (22.7 ± 6.7), shoulder (21.0 ± 8.7), ankle (20.2 ± 8.8), knee (19.5 ± 9.1), and hip (15.4 ± 10.4) (P < .001). Broad distribution was seen in each cohort, with no floor or ceiling effects. The HSS Pedi-FABS score correlated with patient-reported hours per week (r = 0.33), days per week (r = 0.33), and years of participation (r = 0.21) (P < .001 for all). All 3 PROMIS components correlated with HSS Pedi-FABS: PGH (r = 0.28), PGH-PI (r = -0.11), and PGH-F (r = -0.15) (P < .001).

Conclusion

Study findings indicated that the HSS Pedi-FABS is a valid tool for measuring physical activity level in most injured youth athletes, not just those with knee injuries. The correlation of HSS Pedi-FABS with the PGH suggests a positive relationship of childhood physical activity with general health.

The Association of α Angle on Disease Severity in Adolescent Femoroacetabular Impingement

BACKGROUND

Femoroacetabular Impingement (FAI) is a common cause of hip pain in adolescent patients. Clinical exam and radiographic markers, such as α angle and lateral center edge angle (LCEA), are commonly used to aid in the diagnosis of this condition. The purpose of this study was to correlate preoperative α angle and LCEA with preoperative symptoms, intraoperative findings, and preoperative and postoperative patient reported outcomes (PROs) in the adolescent patient.

METHODS

A retrospective analysis of prospectively collected data was conducted for all patients who underwent operative intervention for FAI at an academic institution over an 11-year period. Preoperative imaging was obtained and measured for LCEA and α angle. PROs (modified Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, and UCLA score) were collected preoperatively, as well as 1, 2, and 5 years postoperatively. Operative intervention was either open surgical hip dislocation or arthroscopic, and intraoperative disease was graded using the Beck Classification system. Patients with minimum 1-year follow-up were included in statistical analysis.

RESULTS

There were 86 hips (64 female hips) included with an average age of 16.3 years (range, 10.4 to 20.5 y), with an average of 37 months of follow-up. There was no correlation between severity of preoperative symptoms or difference between pre and postoperative PROs for both α angle and LCEA. Overall, significant improvement was noted in modified Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, and UCLA Score (P<0.001 for each). Independent of preoperative symptoms, increased α angle correlated with more severe intraoperative labral disease (P<0.001), and longer length of labral tear (Corr 0.295, P<0.01). Femoral head and acetabular articular cartilage damage did not correlate with α angle or LCEA, nor did overall severity of disease.

CONCLUSIONS

In adolescent patients with FAI, increased α angle was found to significantly correlate with labral pathology, including increased length of tear and severity of disease, irrespective of preoperative symptoms or postoperative patient reported outcomes.

LEVEL OF EVIDENCE

Level III-retrospective.

5-Azacytidine Potentiates Anti-tumor Immunity in a Model of Pancreatic Ductal Adenocarcinoma

Tumors evolve a variety of mechanisms to escape immune detection while expressing tumor-promoting molecules that can be immunogenic. Here, we show that transposable elements (TE) and gene encoded, tumor-associated antigens (TAA), which can be both highly immunogenic and tumor-promoting, are significantly upregulated during the transition from pre-malignancy to malignancy in an inducible model of pancreatic ductal adenocarcinoma (PDAC). Coincident with the increased presence of TEs and TAAs was the downregulation of gene transcripts associated with antigen presentation, T cell recruitment and intrinsic anti-viral responses, suggesting a unique strategy employed by PDAC to possibly augment tumorigenesis while escaping detection by the immune system. In vitro treatment of mouse and human PDAC cell lines with the DNA methyltransferase inhibitor 5-azacytidine (Aza) resulted in augmented expression of transcripts for antigen presentation machinery and T cell chemokines. When immunocompetent mice implanted with PDAC were therapeutically treated with Aza, we observed significant tumor regression that was not observed in immunocompromised mice, implicating anti-tumor immunity as the principal mechanism of tumor growth control. Analysis of PDAC tumors, immediately following Aza treatment in immunocompetent mice, revealed a significantly greater infiltration of T cells and various innate immune subsets compared to control treatment, suggesting that Aza treatment enhances tumor immunogenicity. Thus, augmenting antigen presentation and T cell chemokine expression using DNA methyltransferase inhibitors could be leveraged to potentiate adaptive anti-tumor immune responses against PDAC.

Desmoplasia and oncogene driven acinar-to-ductal metaplasia are concurrent events during acinar cell-derived pancreatic cancer initiation in young adult mice

The five-year survival rate of patients diagnosed with advanced pancreatic ductal adenocarcinoma (PDAC) has remained static at <5% despite decades of research. With the exception of erlotinib, clinical trials have failed to demonstrate the benefit of any targeted therapy for PDAC despite promising results in preclinical animal studies. The development of more refined mouse models of PDAC which recapitulate the carcinogenic progression from non-neoplastic, adult exocrine subsets of pancreatic cells to invasive carcinoma in humans are needed to facilitate the accurate translation of therapies to the clinic. To study acinar cell-derived PDAC initiation, we developed a genetically engineered mouse model of PDAC, called KPT, utilizing a tamoxifen-inducible Cre recombinase/estrogen receptor (ESR1) fusion protein knocked into the Ptf1a locus to activate the expression of oncogenic KrasG12D and Trp53R270H alleles in mature pancreatic acinar cells. Oncogene-expressing acinar cells underwent acinar-to-ductal metaplasia, and formed pancreatic intraepithelial neoplasia lesions following the induction of oncogene expression. After a defined latency period, oncogene-expressing acinar cells initiated the formation of highly differentiated and fibrotic tumors, which metastasized to the lungs and liver. Whole-transcriptome analysis of microdissected regions of acinar-to-ductal metaplasia and histological validation experiments demonstrated that regions of acinar-to-ductal metaplasia are characterized by the deposition of the extracellular matrix component hyaluronan. These results indicate that acinar cells expressing KrasG12D and Trp53R270H can initiate PDAC development in young adult mice and implicate hyaluronan deposition in the formation of the earliest characterized PDAC precursor lesions (and the progression of pancreatic cancer). Further studies are necessary to provide a comprehensive characterization of PDAC progression and treatment response in KPT mice and to investigate whether the KPT model could be used as a tool to study translational aspects of acinar cell-derived PDAC tumorigenesis.

Use of whole exome sequencing for the identification of Ito-based arrhythmia mechanism and therapy

BACKGROUND

Identified genetic variants are insufficient to explain all cases of inherited arrhythmia. We tested whether the integration of whole exome sequencing with well-established clinical, translational, and basic science platforms could provide rapid and novel insight into human arrhythmia pathophysiology and disease treatment.

METHODS AND RESULTS

We report a proband with recurrent ventricular fibrillation, resistant to standard therapeutic interventions. Using whole-exome sequencing, we identified a variant in a previously unidentified exon of the dipeptidyl aminopeptidase-like protein-6 (DPP6) gene. This variant is the first identified coding mutation in DPP6 and augments cardiac repolarizing current (Ito) causing pathological changes in Ito and action potential morphology. We designed a therapeutic regimen incorporating dalfampridine to target Ito. Dalfampridine, approved for multiple sclerosis, normalized the ECG and reduced arrhythmia burden in the proband by >90-fold. This was combined with cilostazol to accelerate the heart rate to minimize the reverse-rate dependence of augmented Ito.

CONCLUSIONS

We describe a novel arrhythmia mechanism and therapeutic approach to ameliorate the disease. Specifically, we identify the first coding variant of DPP6 in human ventricular fibrillation. These findings illustrate the power of genetic approaches for the elucidation and treatment of disease when carefully integrated with clinical and basic/translational research teams.

Effect of flip angle on the accuracy and repeatability of hepatic proton density fat fraction estimation by complex data-based, T1-independent, T2*-corrected, spectrum-modeled MRI

PURPOSE

To evaluate the effect of flip angle (FA) on accuracy and within-examination repeatability of hepatic proton-density fat fraction (PDFF) estimation with complex data-based magnetic resonance imaging (MRI).

MATERIALS AND METHODS

PDFF was estimated at 3T in 30 subjects using two sets of five MRI sequences with FA from 1° to 5° in each set. One set used 7 msec repetition time and acquired 6 echoes (TR7/E6); the other used 14 msec and acquired 12 echoes (TR14/E12). For each FA in both sets the accuracy of MRI-PDFF was assessed relative to MR spectroscopy (MRS)-PDFF using four regression parameters (slope, intercept, average bias, R(2) ). Each subject had four random sequences repeated; within-examination repeatability of MRI-PDFF for each FA was assessed with intraclass correlation coefficient (ICC). Pairwise comparisons were made using bootstrap-based tests.

RESULTS

Most FAs provided high MRI-PDFF estimation accuracy (intercept range -1.25 to 0.84, slope 0.89-1.06, average bias 0.24-1.65, R(2) 0.85-0.97). Most comparisons of regression parameters between FAs were not significant. Informally, in the TR7/E6 set, FAs of 2° and 3° provided the highest accuracy, while FAs of 1° and 5° provided the lowest. In the TR14/E12 set, accuracy parameters did not differ consistently between FAs. FAs in both sets provided high within-examination repeatability (ICC range 0.981-0.998).

CONCLUSION

MRI-PDFF was repeatable and, for most FAs, accurate in both sequence sets. In the TR7/E6 sequence set, FAs of 2° and 3° informally provided the highest accuracy. In the TR14/E12 sequence set, all FAs provided similar accuracy.

Ultrasonic attenuation and speed of sound of cornstarch suspensions

The goal of this study is to contribute to the physics underlying the material properties of suspensions that exhibit shear thickening through the ultrasonic characterization of suspensions of cornstarch in a density-matched solution. Ultrasonic measurements at frequencies in the range of 4 to 8 MHz of the speed of sound and the frequency-dependent attenuation properties are reported for concentrations of cornstarch in a density-matched aqueous (cesium chloride brine) suspension, ranging up to 40% cornstarch. The speed of sound is found to range from 1483 ± 10 m/s in pure brine to 1765 ± 9 m/s in the 40% cornstarch suspension. The bulk modulus of a granule of cornstarch is inferred to be 1.2(± 0.1) × 10(10) Pa. The attenuation coefficient at 5 MHz increases from essentially zero in brine to 12.0 ± 1.2 dB/cm at 40% cornstarch.

Layer-dependent variation in the anisotropy of apparent integrated backscatter from human coronary arteries

Clinical imaging of the coronary arteries in the cardiac catheterization laboratory using intravascular ultrasound (IVUS) is known to display a three-layered appearance, corresponding to the intima/plaque, media and adventitia. It is not known whether ultrasonic anisotropy arising from these tissues may alter this pattern in future IVUS systems that insonify in the forward direction or obliquely. In anticipation of such devices, the current study was carried out by imaging fresh human coronary arteries in two orthogonal directions in vitro. Twenty-six sites from 12 arteries were imaged with a side-looking IVUS system, and with an acoustic microscope both radially and axially. Side-looking IVUS and radial acoustic microscopy scans demonstrated the typical "bright-dark-bright" pattern of the backscatter, with the media being significantly darker than the other two layers. Images obtained in the axial orientation exhibited a markedly different pattern, with the relative brightness of the media significantly larger than that of the intima/plaque.

Effects of organic matter on the distribution of uranium in soil and plant matrices

This work studied interactions of uranium with pure organic compounds, such as glutathione, and more complex mixtures, such as humic acid and aqueous plant extracts. High performance liquid chromatography with UV absorption interfaced to inductively coupled plasma mass spectrometry sequential detection was used to detect organouranium complexes in a variety of soils and plant materials, indicating that nearly 100% of the uranium extracted from certain plant tissues was bound to organic ligands. In addition, soil sorption experiments indicated that humic acid generally decreased uranium sorption to soils and promoted subsequent desorption of uranium because of uranium partitioning to the organic phase. These experiments demonstrate that organic compounds influence the mobility and chemistry of uranium in the environment.

First Report of Sclerotinia sclerotiorum Infection on Cuphea

Species of the genus Cuphea (family Lythraceae) are being developed as potential domestic sources of medium length fatty acids (lauric and capric) for use in industrial lubricants and detergents. During September 2004, patches of dead plants were observed in test plots of Cuphea sp. cv. PSR-23 (1) (Cuphea viscosissima Jacq. × C. lanceolata W.T. Aiton) near Morris, MN and Prosper, ND, approximately 200 km apart. Seed yield in the diseased Morris field was 78 kg/ha compared with 516 kg/ha in nearby, nonaffected fields of the same variety, for an 85% yield reduction. Stems were split open to reveal long, cylindrical sclerotia as much as 8 mm long. Isolations from diseased stem tissue and sclerotia were identified as Sclerotinia sclerotiorum (Lib.) de Bary and produced typical sized sclerotia (4 to 6 mm in diameter) after 7 days growth on potato dextrose agar (PDA). Cuphea PSR-23 plants were grown in the greenhouse in individual pots for 5 weeks and then inoculated. Three inoculation methods were used. For the first method, ascospores of a sunflower isolate of S. sclerotiorum were sprayed onto blooming flowers and foliage at a rate of 5,000 spores per ml. The inoculated plants were kept in a dark, 18°C mist chamber for 48 h and then returned to a greenhouse maintained at 24/20°C, day/night temperatures. All 20 inoculated plants were visibly colonized by Sclerotinia sp. after 3 days, and all plants were dead by 7 days. The second inoculation used the petiole inoculation technique employed by canola researchers (2). The blade from the third leaf was excised and a micropipette tip containing an agar disk of mycelia of the Cuphea isolate was placed over the cut end of the petiole. Five days after inoculation, all 30 inoculated plants were dead, while none of the 10 control plants (using sterile agar disks on the cut petiole) were affected. Isolations were made from diseased plants inoculated by all methods, and S. sclerotiorum colonies were observed on PDA medium with typical sclerotia from 4 to 6 mm in diameter. The third inoculation method tested root infection. S. sclerotiorum was grown on autoclaved proso millet (Panicum miliaceum L.) seed for 7 days, and 5 g of colonized millet seed was placed in a hole 6 cm from the base of a Cuphea plant, with one plant per 3.7 liter pot. Sunflower (Helianthus annuus L.; oilseed hybrid Cargill 270) plants served as inoculated controls. None of the 20 Cuphea plants were infected via soil inoculations compared with 70% of 30 sunflower plants that developed basal stalk rot and wilt within 2 weeks after inoculation. To our knowledge, this is the first report of S. sclerotiorum infection on Cuphea sp., and is believed to be the first report of infection on any genus within the Lythraceae (loosestrife family). With over 100 annual and perennial species in the genus Cuphea, the possibility of Sclerotinia spp. resistance needs to be investigated to further develop this potential oilseed crop. References: (1) S. J. Knapp and J. M. Crane. Crop Sci. 40:299, 2000. (2) J. Zhao et al. Plant Dis. 88:1033, 2004.

First Report of White Mold Caused by Sclerotinia sclerotiorum on Echium (Echium vulgare)

Echium, also known as common viper's bugloss, is a member of the botanical family Boraginaceae. Echium is being evaluated for its potential use as an oilseed crop in North Dakota. In 2003, 40% of echium plants in a field in Cass County were observed showing classical symptoms of infection by Sclerotinia sclerotiorum. Plants in advanced stages of infection were dead. Stems of dead plants peeled off easily when touched and numerous cylindrical, black sclerotia that were 2 to 3 mm in diameter and 4 to 7 mm long were found in the pith. Younger stem lesions were watery soft, many of them with a white cottony growth on them. Sclerotia and infected stem tissues collected from the field were surface disinfested in a 0.5% NaOCl solution for 30 s, rinsed with sterile distilled water, and air dried before plating on potato dextrose agar (PDA). Samples were incubated at room temperature for 1 week. White mycelium and black sclerotia, characteristic of S. sclerotiorum (Lib.) de Bary, were produced in all dishes. Koch's postulates were fulfilled using the petiole inoculation technique (2). Briefly, 4-mm agar plugs containing hyphal tips of a 2-day-old S. sclerotiorum colony growing on PDA were excised and loaded in the wide opening of 100-μl pipette tips. The second true leaf of 15 3-week-old echium seedlings, growing in plastic pots containing Ready-Mix soil, was cut off with a razor blade leaving an approximately 25-mm long petiole attached to the stem. The leafless petioles of 10 seedlings were capped with a loaded pipette, agar plug first, until the petiole tip broke the inner surface of the plug and the petiole came in contact with the mycelium. The other five seedlings were inoculated with agar plugs without mycelium and used as control plants. Three days after inoculation, all seedlings inoculated with S. sclerotiorum wilted and expressed symptoms similar to those observed in the field. None of the control plants showed symptoms of infection. Black sclerotia were retrieved from infected stems 2 weeks after inoculation, and the pathogen was successfully reisolated onto PDA. Several important North Dakota crops are susceptible to S. sclerotiorum. The identification of echium as a new host for S. sclerotiorum should be considered in the event that this crop is promoted as an alternative for North Dakota agriculture. To our knowledge, this is the first report on the susceptibility of echium to S. sclerotiorum. Other members of the Boraginaceae have been identified as hosts for this pathogen (1). References: (1) G. J. Boland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) L. E. del Río et al. (Abstr.) Phytopathology 91 (suppl.):S176, 2001.

First Report of Soft Rot Caused by Sclerotinia sclerotiorum on Borage in North Dakota

Borage (Borago officinalis) is an oilseed crop that is being evaluated as an alternative crop in North Dakota. During September 2004, borage plants in a field in Cass County, North Dakota were dying from a watery soft rot. The main stems and lateral branches were affected, and affected plants were usually completely lodged and prostrate. Dead plants had bleached and shredded stems with black sclerotia (9.1 ± 3.0 × 2.6 ± 0.5 mm) inside the pith and on the epidermis. At the time of observation, borage plants were flowering and forming pods and seed. Approximately 60% of the plants were visually affected by the watery soft rot. Sclerotia were collected from diseased plants, soaked in a 0.5% NaOCL solution for 30 s, air dried, and placed in petri dishes containing potato dextrose agar (PDA). A fungus grew from the plated sclerotia that subsequently produced white mycelium and black sclerotia (4.8 ± 1.2 × 2.5 ± 1.0 mm), which is characteristic of Sclerotinia sclerotiorum (Lib.) de Bary (3). To confirm pathogenicity, borage plants were inoculated in the greenhouse with a S. sclerotiorum isolate from field-infected borage. Thirteen borage plants were grown from seed in the greenhouse under natural sunlight at a temperature range of 24 ± 3°C. When plants were at the four-leaf stage (approximately 16 cm high), the second leaf was excised from each plant with the petiole remaining on the plant. The leafless petioles were inoculated using a method previously described (2). Petioles of 10 plants were inoculated with PDA containing mycelium of the S. sclerotiorum borage isolate, while petioles of five plants were inoculated with PDA to serve as a control. Three days after inoculation, plants inoculated with the S. sclerotiorum borage isolate were beginning to wilt and 5 days after inoculation, these plants were completely wilted and prostrate, similar to observations made on field-infected plants. Sclerotia collected from the diseased, inoculated plants were placed on PDA, and S. sclerotiorum was successfully recovered. Control plants inoculated with PDA did not show any disease symptoms. Other plant genera in the Boraginaceae are known hosts of S. sclerotiorum (1); however, to our knowledge, this is the first report of borage as a host. References: (1) G. J. Boland and R. Hall, Can. J. Plant Pathol. 16:93, 1994. (2) L. E. del Río et al. (Abstr.) Phytopathology 90(suppl.):S176, 2000. (3) D. L. Tourneau, Phytopathology 69:887, 1979.

Carotid intervention prior to or during coronary artery bypass grafting. When is it necessary?

Management of patients with advanced atherosclerosis involving the extra-cranial carotid and coronary arteries should be individualized based on symptoms and disease severity. A liberal policy to identify high-grade carotid stenosis using duplex ultrasound testing prior to coronary revascularization is recommended. Carotid intervention is efficacious for stroke reduction in patients with severe (>70% diameter reduction), bilateral internal carotid artery disease, especially if testing indicates abnormal cerebral perfusion via the circle of Willis. The morbidity of a combined carotid-coronary revascularization procedure should be less than 5%, but higher stroke and death rates can be expected in urgent cases with recent hemispheric symptoms. Patients with symptomatic >50% internal carotid artery stenosis should be considered for carotid endarterectomy at the time of coronary revascularization. Carotid angioplasty with cerebral protection is also an appropriate option in "high-risk" cardiac patients, especially in vascular centers with expertise and experience in performing this procedure. A policy of carotid endarterectomy prior to coronary bypass grafting is justified only in patients with stable coronary disease, good ejection fraction, and is best-performed using regional anesthesia.

First Report of Sclerotinia sclerotiorum on Niger (Guizotia abyssinica)

Niger is a new crop being grown in North Dakota and Minnesota for the commercial birdseed market. In 2002, approximately 60 and 150 ha of niger were grown in North Dakota and Minnesota, respectively. In September 2002, niger plants in a field located near Prosper, ND showed the following symptoms and signs: bleached, shredded, and broken stems at the basal area, and presence of white mycelium and black sclerotia (2.2 ± 0.8 mm diameter) inside the pith cavity. Approximately 40% of plants in that field showed signs or symptoms of infection. Sclerotia were collected from the pith cavity, soaked in a 0.53% NaOCL solution for 30 s, air dried, and placed in petri dishes containing potato dextrose agar (PDA). A fungal colony grew out from the plated sclerotia that subsequently produced aerial white mycelium and black sclerotia characteristic of Sclerotinia sclerotiorum (Lib.) de Bary. To confirm pathogenicity, 2 groups of 10 30-day-old niger seedlings each were inoculated using the straw test method (2) or petiole inoculation test method (1) with mycelium from a S. sclerotiorum isolate obtained from an infected niger plant; 20 seedlings served as a noninoculated control. At the time of inoculation, seedlings were healthy and approximately 14 cm high. Three days after inoculation using either method, tissue at the inoculated area turned gray. The gray lesions progressed across the majority of the seedling tissue and 1 week after inoculation, all inoculated plants were wilted and dead. S. sclerotiorum was reisolated from infected tissue that was placed on PDA. To our knowledge, this is the first report of S. sclerotiorum causing a stem rot disease of niger or any species in the Guizotia genus. Several of the major crops grown in North Dakota and Minnesota, such as canola, dry edible bean, soybean, and sunflower are susceptible to S. sclerotiorum. Growing niger in rotation with these or other susceptible crops could increase S. sclerotiorum inoculum levels and lead to severe disease outbreaks if conditions are favorable. References: (1) L. E. del Río et al. (Abstr.) Phytopathology 90(Suppl.):S176, 2000. (2) R. Petzoldt and M. H. Dickson, Annu. Rep. Bean Improv. Coop. 39:142, 1996.

Utility of duplex surveillance following iliac artery angioplasty and primary stenting

PURPOSE

To evaluate the clinical outcome and patency rates after iliac artery angioplasty and primary stenting using a noninvasive surveillance protocol that includes duplex ultrasonography.

METHODS

Sixty-seven patients (64 men; mean age 61 +/- 9 years, range 45-83) underwent stenting of 84 iliac systems for claudication (63%), rest pain (9%), tissue loss (20%), or failing lower limb bypass graft (8%). The surveillance algorithm included aortoiliac duplex scanning within 1 month and serial limb pressure measurements and femoral artery waveform analyses during follow-up. Iliac systems with a peak systolic velocity >300 cm/s and velocity ratio >2.0 by duplex and/or symptomatic or hemodynamic deterioration were considered failing and an indication for angiography.

RESULTS

During intermediate-term follow-up ranging to 36 months (mean 12), life table primary, assisted primary, and secondary patency rates for the treated iliac systems were 78%, 90%, and 98%, respectively, at 18 months. Assisted primary iliac system patency at 18 months was significantly worse in the 20 (24%) limbs having an outflow bypass done with or prior to iliac stenting (83% versus 100% without bypass, p = 0.01). Indirect clinical indicators found 17 (20%) suspected failing iliac systems, in which duplex imaging correctly identified 5 of 6 recurrent iliac stenoses and facilitated secondary endovascular intervention. Three (4%) stent occlusions occurred in the treated iliac systems despite surveillance.

CONCLUSIONS

Duplex surveillance after iliac stenting localizes failing inflow segments, optimizes assisted patency of the treated iliac system, and possesses greatest utility in patients with multilevel occlusive disease and outflow reconstructions.

Type-II endoleaks following endovascular AAA repair: preoperative predictors and long-term effects

PURPOSE

To determine the significance of persistent type-II endoleaks and whether they can be predicted preoperatively in patients with abdominal aortic aneurysms (AAA).

METHODS

The charts of all AAA patients treated with the AneuRx stent-graft at a single center from 1996 to 1998 were reviewed. Patients with <12-month follow-up or type-I endoleaks were excluded. The presence or absence of type-II endoleaks was determined from duplex imaging and computed tomographic angiography. Three groups were identified and compared: 16 patients with persistent type-II endoleaks (PE), 14 patients with transient type-II endoleaks (TE), and 16 patients with no endoleak (NE).

RESULTS

The groups did not differ with regard to age, preoperative comorbidities, follow-up time, and AAA neck diameter and length. AAA diameters were 57.1 +/- 9.0 mm for NE, 63.4 +/- 11.4 mm for TE, and 55.6 +/- 4.2 mm for PE. The inferior mesenteric artery (IMA) was patent in 5 (31%) NE patients, 6 (43%) TE patients, and 13 (81%) PE patients (p < 0.01). The number of patent lumbar arteries visualized preoperatively was 0.5 +/- 1.0 in NE, 1.3 +/- 0.8 in TE, and 2.4 +/- 0.6 in PE (p < 0.0001). Patent IMAs (RR 0.82, p < 0.01) and >2 lumbar arteries (RR 0.40, p < 0.0001) were identified as independent preoperative risk factors for persistent endoleaks. There were no changes in mean diameter or volume in aneurysms with persistent endoleaks.

CONCLUSIONS

No adverse clinical events were related to the presence of type-II endoleaks, but there was no decrease in aneurysm size in patients with persistent type-II leaks. Patients with a large, patent IMA, or >2 lumbar arteries on preoperative CT angiography are at higher risk for persistent type-II endoleaks.

Expanded application of in situ replacement for prosthetic graft infection

PURPOSE

The purpose of this study was to analyze the outcome of an individualized treatment algorithm for prosthetic graft infection, including the application of in situ graft replacement, based on clinical presentation, extent of graft infection, and microbiology.

METHODS

There was a retrospective review (1991-2000) of 119 patients with 68 aortoiliofemoral or 51 extracavitary (infrainguinal, 19; axillofemoral, 16; femorofemoral, 16) prosthetic graft infections presenting more than 3 months (range, 3-136 months) after implantation/revision. The treatment algorithm consisted of graft excision with or without ex situ bypass grafts for patients presenting with sepsis or graft-enteric erosion, whereas in situ replacement (autogenous vein, rifampin-bonded polyester, polytetrafluoroethylene [PTFE]) was used in patients with less virulent gram-positive graft infection, in particular infections caused by Staphylococcus epidermidis. Outcomes (death, limb loss, recurrent infection) were correlated with treatment type and infecting organism.

RESULTS

In situ replacement was used in 52% of aortoiliofemoral (autogenous vein, 10; rifampin-bonded polyester, 6; PTFE, 9) and 80% of extracavitary (autogenous vein, 26; PTFE, 9; rifampin, 6) graft infections. Total graft excision with ex situ bypass was performed in 34 patients, including 21 patients with graft-enteric erosion/fistula, with a 21% operative mortality and 9% amputation rate. In situ graft replacement was used to treat 76 graft infections with a 30-day operative mortality rate of 4% and an amputation rate of 2%. Graft excision alone was performed in nine patients with one 30-day death. Gram-positive cocci were the prevalent infecting organisms of both intracavitary (59% of isolates) and extracavitary (76% of isolates) graft infections. S epidermidis was the infecting organism in 40% of patients, accounting for the expanded application of in situ prosthetic replacement using a rifampin-bonded polyester or PTFE prosthesis. During the mean follow-up interval of 26 months, recurrent graft infection developed in 3% (1 of 34) of patients after conventional treatment, 3% (1 of 36) patients after in situ vein replacement, and 10% (4 of 40) patients after in situ prosthetic graft replacement (P >.05). Failure of in situ replacement procedures was the result of virulent and antibiotic-resistant bacterial strains.

CONCLUSIONS

In situ replacement was a safe and durable option in most (64%) patients presenting with prosthetic graft infection. In situ replacement with a rifampin-bonded graft was effective for S epidermidis graft infection, but when the entire prosthesis is involved with either a biofilm or invasive perigraft infection, in situ autogenous vein replacement is preferred. Virulent graft infections presenting with sepsis, anastomotic dehiscence, or graft enteric fistula should continue to be treated with total graft excision, and if feasible, staged ex situ bypass graft.

Duplex surveillance of abdominal aortic stent grafts

Aortic stent grafting is gaining acceptance rapidly as a durable and effective alternative to open surgery for abdominal aortic aneurysms (AAA). Unlike follow-up after open surgical procedures, postplacement surveillance protocols are necessary to ensure long-term freedom from device failure or aneurysm rupture. Surveillance protocols incorporating duplex scanning are effective and may reduce overall postplacement expenses. Specific device or patient anatomic features may be prone to failure, and familiarity with each approved device is a prerequisite to the performance of effective device surveillance studies. Mechanisms of failure of aneurysm exclusion after device placement, or "endoleak," have been described and categorized. Endoleak significance is directly related to location, duration, and influence on AAA diameter. Endoleak type also determines when and whether additional interventions are indicated. Future progress in endovascular AAA exclusion will depend in large part on the reliability and utility of cost-effective postprocedure surveillance protocols incorporating duplex ultrasound imaging.

Primary axillary-subclavian venous thrombosis: is aggressive surgical intervention justified?

Multimodal (thrombolysis, surgical decompression, venous reconstruction, oral anticoagulation) treatment of primary axillary-subclavian venous thrombosis was reviewed to assess the impact of venous patency on functional outcome. Since 1996, 7 patients (6 men, 1 woman) of ages 16-53 years (mean 33 years) presented with symptomatic acute axillosubclavian venous thrombosis as a result of a recent athletic or strenuous arm activity. Five patients had undergone previous (>2 weeks) catheter-directed thrombolysis and venous angioplasty. Diagnostic contrast venography followed by repeat catheter-directed thrombolysis demonstrated abnormal (residual stenosis [n=6] or occlusion [n=1]) axillosubclavian venous segments in all patients. Surgical intervention was performed at a mean interval of 7 days (range 1-19 days) after thrombolysis and consisted of thoracic outlet decompression with scalenectomy and 1st rib resection via a paraclavicular (n=4) or supraclavicular (n=3) approach. Medial claviculectomy or cervical rib resection was performed in 2 patients. Concomitant venous surgery was performed in all patients to restore normal venous patency by circumferential venolysis (n=7) and balloon catheter thrombectomy (n=3), or vein-patch angioplasty (n=2), or endovenectomy (n=5), or internal jugular transposition (n=2). Postoperative venous duplex testing beyond 1 month identified recurrent thrombosis in 4 patients despite therapeutic oral anticoagulation. Subsequent venous recanalization was documented in 3 patients. Poor functional outcome was associated with an occluded venous repair and extensive venous thrombosis on initial presentation. A patent or recanalized venous repair present in 6 of 7 patients was associated with good functional outcome and may justify multimodal intervention in patients with primary axillosubclavian effort thrombosis presenting with recurrent thrombosis and significant residual disease after thrombolysis.

Dosimetry of the I-Plant Model 3500 iodine-125 brachytherapy source

125I brachytherapy sources have been widely used for interstitial implants for a number of years in several tumor sites, especially the prostate. The design of the new I-Plant Model 3500 iodine source is novel, yet its characteristics are similar to those of two existing designs, Model 6711 and the Symmetra. Dosimetry parameters (including dose rate constant, radial dose function, and anisotropy function, as defined by AAPM Task Group 43) were measured with LiF thermoluminescent dosimeters in water-equivalent plastic phantoms. The dose rate constant was found by direct comparison of calibrated I-Plant Model 3500 and Model 6711 seeds in a solid water phantom, to be 1.01 (cGy/h)/U. The radial dose function and anisotropy function are similar to those of the Model 6711 and Symmetra seeds.

Use of rifampin-soaked gelatin-sealed polyester grafts for in situ treatment of primary aortic and vascular prosthetic infections

BACKGROUND

In situ treatment of artery/graft infection has distinct advantages compared to vessel excision and extra-anatomic bypass procedures. Based on animal studies of a rifampin-soaked, gelatin-impregnated polyester graft that demonstrated prolonged in vivo antibacterial activity, this antibiotic-bonded graft was used selectively in patients for in situ treatment of low-grade Gram-positive prosthetic graft infections or primary aortic infections not amenable to excision and ex situ bypass.

METHODS

In a 5-year period (1995-1999), 27 patients with prosthetic graft infection (aortofemoral, n = 18, femorofemoral, n = 3; axillofemoral, n = 1) or primary aortic infection (mycotic aneurysm, n = 3; infected AAA, n = 2) underwent excision of the infected vessel and in situ replacement with a rifampin soaked (45-60 mg/ml for 15 min) gelatin-impregnated polyester graft. All prosthetic graft infections were low grade in nature, caused Gram-positive bacteria (Staphylococcus epidermidis, 16; Staphylococcus aureus, 5; Streptococcus, 1), and were treated electively. Patients with mycotic aortic aneurysm presented with sepsis and underwent urgent or emergent surgery.

RESULTS

Two (8%) patients died-1 as a result of a ruptured Salmonella mycotic aortic aneurysm and the other from methicillin-resistant S. aureus infection following deep vein replacement of an in situ replaced femorofemoral graft. No amputations or late deaths as the result of vascular infection occurred in the 25 surviving patients. Two patients developed recurrent infection caused by a rifampin-resistant S. epidermidis in a replaced aortofemoral graft limb and were successfully treated with graft excision and in situ autogenous vein replacement. Eighteen patients remain alive and clinically free of infection after a mean follow-up interval of 17 months.

CONCLUSIONS

In situ replacement treatment using a rifampin-bonded prosthetic graft for low-grade staphylococcal arterial infection was safe, durable, and associated with eradication of clinical signs of infection. Failure of this therapy was the result of virulent and antibiotic-resistant bacterial strains.

Duplex ultrasound scanning versus computed tomographic angiography for postoperative evaluation of endovascular abdominal aortic aneurysm repair

OBJECTIVE

The purpose of this study was to compare duplex ultrasound scanning and computed tomographic (CT) angiography for postoperative imaging and surveillance after endovascular repair of abdominal aortic aneurysm (AAA).

METHODS

One hundred consecutive patients with AAA underwent endovascular (Medtronic AneuRx, stent graft) aneurysm repair and were imaged with both CT angiography and duplex ultrasound scanning at regular intervals after the procedure. Each imaging modality was evaluated for technical adequacy and for documentation of aneurysm size, endoleak, and graft patency. In concurrent scan pairs, accuracy of duplex scanning was compared with CT.

RESULTS

A total of 268 CT scans and 214 duplex scans were obtained at intervals of 1 to 30 months after endovascular aneurysm repair (mean follow-up interval, 9+/-7 months). All CT scans were technically adequate, and 198 (93%) of 214 duplex scans were technically adequate for the determination of aneurysm size, presence of endoleak, and graft patency. Concurrent (within 7 days of each other) scan pairs were obtained in 166 instances in 76 patients (1-6 per patient). The maximal transverse aneurysm sac diameter measured with both methods correlated closely (r = 0.93; P <.001) without a significant difference on paired analysis. In 92% of scans, measurements were within 5 mm of each other. Diagnosis of endoleak on both examinations correlated closely (P <.001), and compared with CT, duplex scanning had a sensitivity of 81%, a specificity of 95%, a positive predictive value of 94%, and a negative predictive value of 90%. Discordant results occurred in 8% of examinations, and in none of these was the endoleak close to the attachment sites or associated with aneurysm expansion. An endoleak was demonstrated on both tests in all eight patients who had an endoleak judged severe enough to warrant arteriography. Graft patency was documented in each instance, without discrepancy, with both modalities.

CONCLUSIONS

High-quality duplex ultrasound scanning is comparable to CT angiography for the assessment of aneurysm size, endoleak, and graft patency after endovascular exclusion of AAA.

Magnetic resonance angiography is an accurate imaging adjunct to duplex ultrasound scan in patient selection for carotid endarterectomy

PURPOSE

The purpose of this study was to evaluate the accuracy of magnetic resonance angiography (MRA) for categorizing the severity of carotid disease relative to duplex ultrasound scan and cerebral contrast arteriography (CA) to determine if MRA imaging could replace the need for cerebral angiography in cases of indeterminate or inadequate duplex scan imaging.

METHODS

Seventy-four carotid bifurcations in 40 patients undergoing 45 carotid endarterectomies from 1996 to 1998 were imaged with duplex ultrasound scan; MRA (two-dimensional neck and three-dimensional intracranial, time-of-flight technique); and biplanar, digital subtraction cerebral arteriography. Studies were blindly reviewed by one reader who used established threshold velocity criteria for the duplex scan and the North American Symptomatic Carotid Endarterectomy Trial method for MRA and CA to determine the percentage of diameter reduction of the internal carotid artery (ICA). Disease severity was grouped into four categories (< 50%, 50%-74%, 75%-99% stenosis and occlusion), and the results of MRA and duplex ultrasound scan were compared with CA.

RESULTS

Sensitivity, specificity, positive predictive value, and negative predictive value for detection of > 50% ICA stenosis were 100%, 96%, 98%, and 100% for MRA and 100%, 72%, 88%, and 100% for duplex ultrasound scan, respectively; similarly, for detection of > 75% ICA stenosis values were 100%, 77%, 76%, and 100% for MRA and 90%, 74%, 72%, and 91% for duplex ultrasound scan, respectively. Both MRA and duplex ultrasound scan accurately differentiated all cases of > 95% stenosis (n = 7) from occlusion (n = 4). Short length ICA flow gaps were present on MRA in all cases of 75% to 99% stenosis and one half of cases of CA-defined 50% to 74% stenosis. In patients with 50% to 74% stenosis, the mean angiographic stenosis was significantly greater when a flow gap was present on MRA (64% +/- 6%) versus no flow gap (57% +/- 7%) (P =.04). There was overall agreement among duplex ultrasound scan, MRA, and CA in 73% of carotids imaged. Of the 24% discordant results between MRA and duplex ultrasound scan, MRA correctly predicted disease severity in all cases, and inaccurate duplex ultrasound scan results were due to overestimation in 83% of cases. The operative plan was altered by CA findings in only one patient (2%) after duplex ultrasound scan and MRA.

CONCLUSIONS

MRA can accurately categorize the severity of carotid occlusive disease. Duplex ultrasound scan facilitates patient selection for carotid endarterectomy in most cases, but adjunct use of MRA improves diagnostic accuracy for > 75% stenoses and may obviate the need for cerebral arteriography when duplex scan results are inconclusive or demonstrate borderline disease severity.

Trichophytic granuloma of the vulva

Fungal infections causing deep tissue involvement are known as trichophytic granulomas. We describe an unusual case of trichophytic granuloma presenting in the vulva of a 39-year-old woman.

A review of health-based comparative risk assessments in the United States

Comparing the risks posed by specific environmental hazards has become attractive to policy makers and legislative bodies as an aid to budgeting and other policy decisions. This paper reviews the human health-based findings from the first federal comparative risk assessment project and subsequent reviews conducted by 15 states and local government agencies in the United States. Methods are described on conducting comparative risk assessments that include substantive involvement of the public and special interest organizations. A consolidation of the comparative risk assessments of 15 states revealed good agreement with federal health-based environmental hazard priorities and partial agreement with local-government health departments. In descending order of priority, indoor air pollutants (excluding radon), criteria air pollutants, hazardous air pollutants, indoor radon, lead contamination, inactive hazardous waste sites, and drinking water at the tap are the highest ranked environmental hazards to human health.

Intraoperative duplex monitoring of infrainguinal vein bypass procedures

PURPOSE

The purpose of this study was to evaluate intraoperative duplex scanning of infrainguinal vein bypass grafts to detect technical and hemodynamic problems, monitor their repair, and correlate findings with the incidence of thrombosis and stenosis repair rates within 90 days of operation.

METHODS

Color duplex scanning was used at operation to assess vein/anastomotic patency and velocity spectra waveforms of 626 infrainguinal vein bypass grafts (in situ saphenous, 228 grafts; nonreversed translocated saphenous, 170 grafts; reversed saphenous, 147 grafts; alternative [arm, lesser saphenous], 81 grafts) to the popliteal (n = 267 grafts), infrageniculate (n = 323 grafts), or pedal artery (n = 36 grafts). The entire bypass graft was scanned after intragraft injection of papaverine hydrochloride (30-60 mg) to augment graft flow. Vein/anastomotic/artery segments with velocity spectra that indicate highly disturbed flow (peak systolic velocity, >180 cm/sec; spectral broadening; velocity ratio at site, >3) were revised. Grafts with a low peak systolic velocity less than 30 to 40 cm/s and high outflow resistance (absent diastolic flow) underwent procedures (distal arteriovenous fistula, sequential bypass grafting) to augment flow; if this was not possible, the grafts were treated with an antithrombotic regimen, including heparin, dextran, and antiplatelet therapy.

RESULTS

Duplex scanning prompted revision of 104 lesions in 96 (15%) bypass grafts, including 82 vein/anastomotic stenoses, 17 vein segments with platelet thrombus, and 5 low-flow grafts. Revision rate was highest (P <.01) for alternative vein bypass grafts (27%) compared with the other grafting methods (reversed vein bypass grafts, 10%; nonreversed translocated, 13%; in situ, 16%). A normal intraoperative scan on initial imaging (n = 464 scans) or after revision (n = 67 scans) was associated with a 30-day thrombosis rate of 0.2% and a revision rate of 0.8% for duplex-detected stenosis (peak systolic velocity, >300 cm/s; velocity ratio, >3.5). By comparison, 20 of 95 bypass grafts (21%) with a residual (n = 29 grafts) or unrepaired duplex stenosis (n = 53 grafts) or low flow (n = 13 grafts) had a corrective procedure for graft thrombosis (n = eight grafts) or stenosis (n = 12 grafts; P <.001). Overall, 8% of patients with bypass grafts underwent a corrective procedure within 90 days of operation. Secondary graft patency was 99.4% at 30 days and 98.8% at 90 days (eight graft failures).

CONCLUSION

The observed 15% intraoperative revision rate coupled with a low 90-day failure/revision rate (2.5%) for bypasses with normal papaverine-augmented duplex scans supports the routine use of this diagnostic modality to enhance the precision and early results of infrainguinal vein bypass procedures.

Endovascular-assisted versus conventional in situ saphenous vein bypass grafting: cumulative patency, limb salvage, and cost results in a 39-month multicenter study

OBJECTIVE

In this retrospective multicenter study, the results of a minimally invasive method of endovascular-assisted in situ bypass grafting (EISB) versus "open" conventional in situ bypass grafting (CISB) were evaluated with a comparison of primary and secondary patency, limb salvage, and cost.

METHODS

Enrolled in this study were 273 patients: 117 underwent CISB (42 femoropopliteal, 75 femorocrural) and 156 underwent EISB (41 femoropopliteal, 115 femorocrural). EISB was performed with an angioscopic Side Branch Occlusion system and an angioscopically guided valvulotome. All the patients underwent follow-up examination with serial color-flow ultrasound scanning.

RESULTS

Both groups had similar comorbid risk factors for diabetes mellitus, coronary artery heart disease, hypertension, and cigarette smoking. The primary patency rates (CISB, 78.2% +/- 5% [SE]; EISB, 70.5% +/- 5%; P =.156), the secondary patency rates (CISB, 84.1% +/- 4%; EISB, 82.9% +/- 5%; P =.26), and the limb salvage rates (CISB, 85.8%; EISB, 88.4%; P =.127) were statistically similar, with a follow-up period that extended to 39 months (mean, 16.6 months; range, 1 to 40 months). In veins that were less than 2.5 to 3.0 mm in diameter, the EISB grafts fared poorly, with an increased incidence of early (12-month) graft thromboses (CISB, 10 grafts, 8.5%; EISB, 24 grafts, 15.3%). However, wound complications (CISB, 23%; EISB, 4%; P =.003), mean hospital length of stay (CISB, 6.5 days +/- 4.83; EISB, 3.2 days +/- 3.19; P =.001), and mean hospital charges (CISB, $25,349 +/- $19,476; EISB, $18,096 +/- $14,573; P =.001) were all significantly reduced in the EISB group.

CONCLUSION

The CISB and EISB midterm primary and secondary patency and limb salvage rates were statistically similar. In smaller veins (< 2.5 to 3.0 mm in diameter), however, EISB is not appropriate because overly aggressive instrumentation may cause intimal trauma, with resultant early graft failure. With the avoidance of a long leg incision in the EISB group, wound complications and hospital length of stay were significantly reduced, which lowered hospital charges and justified the additional cost of the endovascular instruments. When in situ bypass grafting is contemplated, EISB in appropriate patients is a safe, minimally invasive, and cost-effective alternative to CISB.

Unsymmetrical cyclic ureas as HIV-1 protease inhibitors: novel biaryl indazoles as P2/P2' substituents

The preparation of unsymmetrical cyclic ureas bearing novel biaryl indazoles as P2/P2' substituents was undertaken, utilizing a Suzuki coupling reaction as the key step. Compound 6i was equipotent to the lead compound of the series SE063.

A rational algorithm for duplex scan surveillance after carotid endarterectomy

PURPOSE

This study was undertaken to determine the appropriate timing and frequency of duplex ultrasound scanning after carotid endarterectomy (CEA) for the detection of high-grade stenosis caused by recurrent carotid stenosis or contralateral atherosclerotic disease progression.

METHODS

In 221 patients who underwent 242 CEAs, duplex scanning was performed before, during, and after operation (in 3-month to 6-month intervals). High-grade internal carotid artery (ICA) stenosis (peak systolic velocity, >300 cm/s; diastolic velocity, >125 cm/s; ICA/common carotid artery ratio, >4) prompted the recommendation for repair. An average of four postoperative scanning procedures was performed during a mean follow-up period of 27.4 months.

RESULTS

Intraoperative duplex scan results prompted the immediate revision of 12 repairs (4.9%), and one perioperative stroke (<1%) occurred. Six CEAs (2.7%) had asymptomatic recurrent stenosis (>50% diameter-reduction [DR]; systolic velocity, >125 cm/s) develop. Only one of six patients had >75% DR stenosis develop and underwent reoperation (<1% yield for CEA surveillance). The yield of surveillance of the unoperated ICA was higher (P =.003), and 12% of unoperated sides had progressive stenosis (n = 21) or occlusion (n = 3) develop, which led to seven CEAs for high-grade stenosis. Disease progression to >75% DR stenosis was five times as frequent (P =.002) in patients with >50% DR stenosis initially. All patients but one who required contralateral endarterectomy for disease progression had >50% ICA stenosis when first seen. During the follow-up period, no disabling strokes ipsilateral to an operated carotid artery occurred, but three strokes occurred in the hemisphere of the contralateral unoperated ICA.

CONCLUSION

The yield of duplex scan surveillance after CEA was low. Only 13 patients (5.9%) had severe disease develop to warrant additional intervention. Progression of contralateral disease rather than restenosis was the most common abnormality that was identified. Duplex scanning at 1-year to 2-year intervals after CEA is adequate when a technically precise repair is achieved and minimal contralateral disease (<50% DR) is present. A policy of duplex scan surveillance and reoperation for high-grade stenosis was associated with a 1.6% incidence rate of disabling stroke during the follow-up period.

A review of the effects of hazardous waste on reproductive health

Approximately 1 in 4 Americans lives within 4 miles of a hazardous waste site according to the Environmental Protection Agency. In light of this large proportion and the public's high level of concern that hazardous waste causes health problems, it is important for primary care physicians and other health care providers to know that residential proximity to some kinds of hazardous waste sites is associated with adverse reproductive effects. Findings from both state-based surveillance programs and studies of individual hazardous waste sites have shown increased risk of congenital malformations and reductions in birth weight among infants born to parents living near hazardous waste sites. This article summarizes salient literature on human health effects of hazardous waste and suggests actions for primary care providers to consider.

Key environmental human health issues in the Great Lakes and St. Lawrence River basins

In May 1997, Health Conference '97-Great Lakes/St. Lawrence, an international conference on the effects of the environment on human health in the Great Lakes and St. Lawrence River basins, was held in Montreal, Québec, Canada. This was the third international conference on this topic sponsored by agencies in the United States and Canada. More than 120 platform and poster presentations were given by scientists of different disciplines from the Great Lakes region and elsewhere. The presentations represented the most current research findings on the effects of the Great Lakes environment on human health. The reports covered environmental contaminant levels of persistent toxic substances (PTSs), routes and pathways of exposure, exposure assessment and human tissue levels of PTSs, human health outcomes, risk communication and assessment, and approaches to scientific collaboration. Reports indicate that levels of contaminants in the Great Lakes and St. Lawrence River basins have generally declined since the 1970s, although certain contaminants have plateaued or slightly increased. The findings include elevated body burden levels of contaminants in persons who consume large amounts of some Great Lakes sport fish, developmental deficits and neurologic problems in children of some fish-consuming parents, nervous system dysfunction in adults, and disturbances in reproductive parameters. The findings underscore the need for better public health intervention strategies.

Duplex features of vein graft stenosis and the success of percutaneous transluminal angioplasty

PURPOSE

To determine if criteria exist that are correlated to a successful outcome after balloon angioplasty for vein graft stenosis.

METHODS

During a 5-year period, duplex surveillance of 380 infrainguinal vein bypasses identified 76 hemodynamically failing grafts (87 stenoses) requiring intervention. Percutaneous transluminal angioplasty (PTA) was selected over surgical repair based on 3 criteria: time interval from primary grafting procedure, vein graft diameter, and stenosis length. The 28 (32%) stenoses (20 grafts) treated by PTA were used in a retrospective analysis to test if any variables favored a successful outcome. Patient and lesion characteristics, graft patency, and restenosis following PTA were correlated with duplex features of the stenosis recorded prior to, immediately after, and at 3- to 6-month intervals postprocedurally.

RESULTS

Lesion characteristics that correlated with a successful outcome were vein size > or = 3.5 mm, lesion length < 2 cm, and appearance > 3 months after surgery. Conduit type, PTA site, patient demographics, and indication for bypass did not correlate with PTA durability. Nineteen lesions in 13 grafts met these criteria (group 1), while 9 stenoses in 7 grafts did not (group 2). Lesion severity based on duplex velocity measurements were similar in both groups before (p = 0.40) and after (p = 0.32) treatment. During the mean 21-month follow-up, group 1 grafts required less intervention (p = 0.035). At last follow-up, hemodynamic changes were durable in group 1 (p = 0.0068) but not in group 2 (p = 0.39).

CONCLUSIONS

Selection of vein graft stenoses for treatment by PTA can be based on temporal and duplex data. PTA of short (< 2 cm) stenoses in good caliber veins (> or = 3.5 mm) appearing > 3 months after bypass placement was durable with a late intervention rate of approximately 10%. Direct surgical repair or replacement is recommended for early (< 3 months) and/or long segment stenoses that develop in small caliber conduits.

Surgical and endovascular intervention for infrainguinal vein graft stenosis

PURPOSE

The purpose of this study was to evaluate the stenosis-free patency of open repair (vein-patch angioplasty, interposition, jump grafting) and percutaneous transluminal balloon angioplasty (PTA) of 144 vein graft stenoses that were detected during duplex scan surveillance after infrainguinal vein bypass grafting.

METHODS

Patients who underwent revision of an infrainguinal vein bypass graft were analyzed for type of vein conduit, vascular laboratory findings leading to revision, repair techniques, assisted graft patency rate, procedure mortality rate, and restenosis of the repair site.

RESULTS

The time of postoperative revision ranged from 1 day to 133 months (mean, 13 months). One hundred eighteen primary and 26 recurrent stenoses (peak systolic velocity, >300 cm/s) in 52 tibial and 35 popliteal vein bypass grafts were identified by means of duplex scanning. The repairs consisted of 77 open procedures (vein-patch angioplasty, 28; vein interposition, 33; jump graft, 9; primary repair, 3) and 67 PTAs. No patient died as a result of intervention. Cumulative assisted graft patency rate (life-table analysis) was 91% at 1 year and 80% at 3 years. At 2 years, cumulative assisted graft patency rate was comparable for saphenous vein grafts (reversed, 94%; in situ, 88%; nonreversed, 63%) and alternative vein grafts (89%). Stenosis-free patency rate at 2 years was identical (P =.55) for surgical intervention (63%) and endovascular intervention (63%) but varied with type of surgical revision (P =.04) and time of intervention (<4 months, 45%; >4 months, 71%; P =.006). The use of duplex scan-monitored PTA to treat focal stenoses (<2 cm) and late-appearing stenoses (>3 months) was associated with a stenosis-free patency rate that was 89% at 1 year. After intervention, the alternative vein bypass grafts necessitated twice the reinterventions per month of graft survival (P =.01). Bypass graft to the popliteal versus infrageniculate arteries, site of graft stenosis (vein conduit, anastomotic region), and repair of a primary versus a recurrent stenosis did not influence the outcome after intervention.

CONCLUSION

The revision of duplex scan-detected vein graft stenosis with surgical or endovascular techniques was associated with an excellent patency rate, including when intervention on alternative vein conduits or treatment of restenosis was necessary. When PTA was selected on the basis of clinical and duplex scan selection criteria, the endovascular treatment of focal vein graft stenosis was effective, durable, and comparable with the surgical revision of more extensive lesions.

Kenny-Caffey syndrome and microorchidism

We report on two adolescent boys with Kenny-Caffey syndrome and microorchidism. The first patient had elevated levels of serum follicle-stimulating hormone, but normal levels of luteinizing hormone and testosterone. There was no evidence of a microdeletion of the Y chromosome. The second patient had Leydig cell hyperplasia with normal seminiferous tubules and spermatogenesis, and normal pituitary histologic findings at autopsy. The presence of microorchidism in these patients confirms the previous observations and suggests subfertility, but does not fully clarify the pathogenesis.

Design and selection of DMP 850 and DMP 851: the next generation of cyclic urea HIV protease inhibitors

BACKGROUND

Recent clinical trials have demonstrated that HIV protease inhibitors are useful in the treatment of AIDS. It is necessary, however, to use HIV protease inhibitors in combination with other antiviral agents to inhibit the development of resistance. The daunting ability of the virus to rapidly generate resistant mutants suggests that there is an ongoing need for new HIV protease inhibitors with superior pharmacokinetic and efficacy profiles. In our attempts to design and select improved cyclic urea HIV protease inhibitors, we have simultaneously optimized potency, resistance profile, protein binding and oral bioavailability.

RESULTS

We have discovered that nonsymmetrical cyclic ureas containing a 3-aminoindazole P2 group are potent inhibitors of HIV protease with excellent oral bioavailability. Furthermore, the 3-aminoindazole group forms four hydrogen bonds with the enzyme and imparts a good resistance profile. The nonsymmetrical 3-aminoindazoles DMP 850 and DMP 851 were selected as our next generation of cyclic urea HIV protease inhibitors because they achieve 8 h trough blood levels in dog, with a 10 mg/kg dose, at or above the protein-binding-adjusted IC90 value for the worst single mutant--that containing the Ile84-->Val mutation.

CONCLUSIONS

In selecting our next generation of cyclic urea HIV protease inhibitors, we established a rigorous set of criteria designed to maximize chances for a sustained antiviral effect in HIV-infected individuals. As DMP 850 and DMP 851 provide plasma levels of free drug that are sufficient to inhibit wild-type HIV and several mutant forms of HIV, they could show improved ability to decrease viral load for clinically significant time periods. The ultimate success of DMP 850 and DMP 851 in clinical trials might depend on achieving or exceeding the oral bioavailability seen in dog.

Postural epigastric pain: a unique symptom of primary cytomegalovirus gastritis?

Cytomegalovirus (CMV) gastritis has been reported in transplant patients. Symptoms are considered nonspecific, and gastroscopy with biopsy is usually performed to establish the diagnosis. Three patients are described here 1 to 3 months after solid organ transplantation, with primary CMV gastritis, confirmed by gastroscopy, histopathologic examination and cultures. The clinical presentation in all three cases was sharp epigastric pain that decreased in a supine position, increased while sitting and further increased when standing or walking. The epigastric pain completely resolved after treatment with ganciclovir. To the best of our knowledge, such postural epigastric pain has not been described as a specific symptom in any other clinical entity and may be a unique sign of primary CMV gastritis.

A model of wound healing in chronically radiation-damaged rat skin

The aim of this investigation was to develop a model for studying the chronic effects of radiation on wound healing in the rat. Six months after rats received a single radiation exposure of 20 Gy, a random-pattern dorsal skin flap was elevated. Two weeks after the flap was elevated, irradiated animals showed diminished scar formation and wound breaking strength, as compared with controls (P < 0.05). The effect of hyperbaric oxygen treatment was investigated in some rats who received 20 sessions at 2.4 atmospheres absolute for 90 min daily, 5 days per week, prior to flap elevation and 10 sessions after creation of the flap. Treated animals showed a trend toward improvements in wound breaking strength and scar formation (P = 0.06). A reproducible model of chronic radiation damage in the rat was established. Further studies involving investigations at times more that 2 weeks post-wounding are needed.

Potent cyclic urea HIV protease inhibitors with 3-aminoindazole P2/P2' groups

Cyclic ureas containing 3-aminoindazole P2/P2' groups are extremely potent inhibitors of HIV protease. The parent 3-aminoindazole 6 showed a Ki < 0.01 nM but poor translation of enzyme activity to antiviral activity was observed. A series of 3-alkylaminoindazoles revealed that translation improved with increasing lipophilicity. An X-ray crystal structure of 6 bound to HIV protease was obtained.

A new, non-destructive method for analysis of clinical samples with FT-IR microspectroscopy. Breast cancer tissue as an example

A new method for infrared analysis of tissues and cells is presented. The method is based on Fourier transform infrared microspectroscopy coupled with attenuated total reflectance. The technique allows spectroscopic measurements on the same samples used by pathologists for histopathological evaluation, e.g. stained samples on plain glass slides. Since the same specimen can be used as for histopathology, the method does not require sample preparation or modification. Significantly, the sample is not damaged. Glass absorbs in the infrared and thus has not been used previously in infrared analysis of tissues and cells. Conventional infrared techniques utilize expensive substrates, such as BaF2 windows and gold coated slides which do not absorb infrared radiation. However, these measurements require special preparation and result in the destruction of the sample. Breast cancer tissues were examined to demonstrate the feasibility and reproducibility of the new method. Linear discriminant analysis was used to discriminate and classify three types of cells: benign, atypical hyperplasia and malignant. It was demonstrated that benign vs. malignant cells were discriminated with 100% accuracy, benign vs. atypical hyperplasia were discriminated with 100% accuracy and malignant vs. atypical hyperplasia were discriminated with an accuracy of 90% and higher.

Predicting bacteremia in patients with sepsis syndrome. Academic Medical Center Consortium Sepsis Project Working Group

The goal of this study was to develop and validate clinical prediction rules for bacteremia and subtypes of bacteremia in patients with sepsis syndrome. Thus, a prospective cohort study, including a stratified random sample of 1342 episodes of sepsis syndrome, was done in eight academic tertiary care hospitals. The derivation set included 881 episodes, and the validation set included 461. Main outcome measures were bacteremia caused by any organism, gram-negative rods, gram-positive cocci, and fungal bloodstream infection. The spread in probability between low- and high-risk groups in the derivation sets was from 14.5% to 60.6% for bacteremia of any type, from 9.8% to 32.8% for gram-positive bacteremia, from 5.3% to 41.9% for gram-negative bacteremia, and from 0.6% to 26.1% for fungemia. Because the model for gram-positive bacteremia performed poorly, a model predicting Staphylococcus aureus bacteremia was developed; it performed better, with a low- to high-risk spread of from 2.6% to 21.0%. The prediction models allow stratification of patients according to risk of bloodstream infections; their clinical utility remains to be demonstrated.