Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

BACKGROUND

Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.

METHODS

This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.

RESULTS

The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (β coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.

CONCLUSION

Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely.

Magnetic Resonance Imaging Features and Prognostic Indicators of Local Recurrence after Curettage and Cementation of Atypical Cartilaginous Tumour in the Appendicular Skeleton

Objective: The aim of this study is to determine MRI features that may be prognostic indicators of local recurrence (LR) in patients treated with curettage and cementation of atypical cartilaginous tumours (ACTs) in the appendicular skeleton. Materials and Methods: This study is a retrospective review of adult patients with histologically confirmed appendicular ACT. The data collected included age, sex, skeletal location and histology from curettage, the presence of LR and oncological outcomes. The pre-operative MRI characteristics of the ACT reviewed by a specialist MSK radiologist included lesion location, lesion length, degree of medullary filling, bone expansion, cortical status and the presence of soft tissue extension. Results: A total of 43 patients were included, including 9 males and 34 females with a mean age of 42.8 years (range: 25-76 years). Tumours were located in the femur (n = 19), humerus (n = 15), tibia (n = 5), fibula (n = 2) and radius and ulna (n = 1 each). A total of 19 lesions were located in the diaphysis, 12 in the metadiaphysis, 6 in the metaphysis and 6 in the epiphysis. The mean tumour length was 61.0 mm (range: 12-134 mm). The mean follow up was 97.7 months (range: 20-157 months), during which 10 (23.3%) patients developed LR, 7 (70%) of which were asymptomatic and 3 (30%) of which presented with pain. Four patients required repeat surgery with no associated death or evidence of metastatic disease. LR was significantly commoner with tumours arising in the epiphysis or metadiaphysis, but no MRI features were predictive of LR. Conclusions: No relationship was found between the apparent 'aggressiveness' of an ACT of the appendicular skeleton on MRI and the development of LR following treatment with curettage and cementation.

Image-guided synovial biopsy with a focus on infection

Image-guided biopsy of the synovium is a relatively uncommon but safe procedure with a high-diagnostic yield in the correct clinical scenario. Whilst surgical and arthroscopic techniques are still commonly performed and remain the gold standard, they are more invasive, expensive and not widely available. Ultrasound and X-ray-guided synovial biopsy are being increasingly performed by radiologists to diagnose both native and periprosthetic joint infection (PJI) to guide surgical and microbiological management. The purpose of this review article is to present the historical background to synovial biopsy particularly related to potential joint infection, including common and uncommon pathogens encountered, sampling techniques and pitfalls, focusing mainly on its role in PJI and its role in patient pathways and decision-making within a joint infection multi-disciplinary framework.

Total Ankle Replacement Versus Arthrodesis for End-Stage Ankle Osteoarthritis: A Randomized Controlled Trial

BACKGROUND

End-stage ankle osteoarthritis causes severe pain and disability. There are no randomized trials comparing the 2 main surgical treatments: total ankle replacement (TAR) and ankle fusion (AF).

OBJECTIVE

To determine which treatment is superior in terms of clinical scores and adverse events.

DESIGN

A multicenter, parallel-group, open-label randomized trial. (ISRCTN registry number: 60672307).

SETTING

17 National Health Service trusts across the United Kingdom.

PATIENTS

Patients with end-stage ankle osteoarthritis, aged 50 to 85 years, and suitable for either procedure.

INTERVENTION

Patients were randomly assigned to TAR or AF surgical treatment.

MEASUREMENTS

The primary outcome was change in Manchester-Oxford Foot Questionnaire walking/standing (MOXFQ-W/S) domain scores between baseline and 52 weeks after surgery. No blinding was possible.

RESULTS

Between 6 March 2015 and 10 January 2019, a total of 303 patients were randomly assigned; mean age was 68 years, and 71% were men. Twenty-one patients withdrew before surgery, and 281 clinical scores were analyzed. At 52 weeks, the mean MOXFQ-W/S scores improved for both groups. The adjusted difference in the change in MOXFQ-W/S scores from baseline was -5.6 (95% CI, -12.5 to 1.4), showing that TAR improved more than AF, but the difference was not considered clinically or statistically significant. The number of adverse events was similar between groups (109 vs. 104), but there were more wound healing issues in the TAR group and more thromboembolic events and nonunion in the AF group. The symptomatic nonunion rate for AF was 7%. A post hoc analysis suggested superiority of fixed-bearing TAR over AF (-11.1 [CI, -19.3 to -2.9]).

LIMITATION

Only 52-week data; pragmatic design creates heterogeneity of implants and surgical techniques.

CONCLUSION

Both TAR and AF improve MOXFQ-W/S and had similar clinical scores and number of harms. Total ankle replacement had greater wound healing complications and nerve injuries, whereas AF had greater thromboembolism and nonunion, with a symptomatic nonunion rate of 7%.

PRIMARY FUNDING SOURCE

National Institute for Health and Care Research Heath Technology Assessment Programme.

MRI differentiation of low-grade and high-grade chondrosarcoma of the shoulder girdle, chest wall and pelvis: a pictorial review based on 111 consecutive cases

Approximately 40% of conventional chondrosarcomas arise from the shoulder girdle, chest wall and pelvis. This pictorial review describes the MRI features which may aid in the differentiation of Grade 1 chondrosarcoma (Gd1-CS) from high-grade chondrosarcoma (HG-CS) and dedifferentiated chondrosarcoma (DD-CS) in these locations, based on literature review and assessment of 111 consecutive cases presenting to the senior authors institution over a 13-year period. Of the 111 patients reviewed (71 males and 40 females; mean age 54.3 years; range 17-92 years), 27 were Gd1-CS, 72 were HG-CS and 12 were DD-CS. Tumours arising from the scapula, acetabulum, pubis/ischium and sacrum were more likely to be HG-CS, as were intramedullary tumours. MRI features associated with HG-CS and DD-CS included cortical destruction, bone oedema, soft tissue oedema, tumour necrosis, intermediate T2W SI and joint invasion. The presence of a soft tissue mass became a significant differentiating feature for tumours arising within the medullary cavity, but this was location-specific and did not differentiate between Gd1-CS and HG-CS/DD-CS arising from the sternum or clavicle.

Morphology of the entering and exiting nerve as a differentiating feature of benign from malignant peripheral nerve sheath tumours of the brachial plexus

OBJECTIVE

To identify if morphology of the entering and exiting nerve involved by a nerve sheath tumour in the brachial plexus can help differentiate between benign (B) and malignant (M) peripheral nerve sheath tumours (PNSTs).

MATERIALS AND METHODS

Retrospective review of 85 patients with histologically confirmed primary PNSTs of the brachial plexus over a 12.5-year period. Clinical data and all available MRI studies were independently evaluated by 2 consultant musculoskeletal radiologists blinded to the final histopathological diagnosis assessing for maximal lesion dimension, visibility and morphology of the entering and exiting nerve, and other well-documented features of PNSTs.

RESULTS

The study included 47 males and 38 females with mean age 46.7 years (range, 8-81 years). There were 73 BPNSTs and 12 MPNSTs. The entering nerve was not identified in 5 (7%), was normal in 17 (23%), was tapered in 38 (52%) and showed lobular enlargement in 13 (18%) BPNSTs compared with 0 (0%), 0 (0%), 2 (17%) and 10 (83%) MPNSTs respectively. The exiting nerve was not identified in 5 (7%), was normal in 20 (27%), was tapered in 42 (58%) and showed lobular enlargement in 6 (8%) BPNSTs compared with 4 (33%), 0 (0%), 2 (17%) and 6 (50%) MPNSTs respectively. Increasing tumour size, entering and exiting nerve morphology and suspected MRI diagnosis were statistically significant differentiators between BPNST and MPNST (p < 0.001). IOC for nerve status was poor to fair but improved to good if normal/tapered appearance were considered together with improved specificity of 81-91% for BPNST and sensitivity of 75-83%.

CONCLUSIONS

Morphology of the adjacent nerve is a useful additional MRI feature for distinguishing BPNST from MPNST of the brachial plexus.

Pathological fracture in paediatric bone tumours and tumour-like lesions: A predictor of benign lesions?

OBJECTIVE

To determine the incidence and causes of pathological fractures in paediatric bone tumours and tumour-like lesions, and to determine if they are predictive of benign lesions.

METHODS AND MATERIALS

Retrospective review of children with suspected bone tumours referred to a specialist musculoskeletal oncology service between September 2019 and August 2020. Data recorded included patient age and gender, lesion location, the presence of a pathological fracture on the initial plain radiograph, and the final diagnosis made either by image-guided biopsy/curettage or based on typical imaging features.

RESULTS

231 patients were included with 233 lesions (138 males and 93 females with mean age 10.5 years, range 3 months-18 years). Final diagnosis was based on histology in 85 (36.5%) cases and imaging in 148 (63.5%) cases, 52 (22.3%) lesions classed as non-neoplastic, 139 (59.7%) as benign and 42 (18%) as malignant. Pathological fractures were seen in 41 cases (17.6%) at presentation, involving the humerus in 19 (46.3%), the femur in 14 (34.1%), the tibia in 3 (7.3%), the fibula and radius in two each (4.9%) and the second toe proximal phalanx in 1 (2.4%) (p < 0.001). The commonest underlying lesions included simple bone cyst (n = 17; 41.5%) and non-ossifying fibroma (n = 10; 24.4%). Only 4 cases (9.75%) were malignant, one case each of osteosarcoma, Ewing sarcoma, leukaemia and BCOR undifferentiated round cell sarcoma. Pathological fracture occurred in 27.7% of non-malignant lesions and 9.5% of malignant lesions, this difference being statistically significant (p < 0.001).

CONCLUSION

Pathological fractures were seen in 17.6% of paediatric bone tumours, tumour-like lesions, being significantly associated with humeral location and non-malignant diagnosis.

ADVANCES IN KNOWLEDGE

Demonstrates the frequency, location and underlying diagnosis of pathological fractures in paediatric bone tumour and tumour-like lesions.

The incidence and diagnostic relevance of pathological fracture in conventional central chondrosarcoma

OBJECTIVE

To determine the incidence and diagnostic relevance of pathological fracture in patients with conventional central chondrosarcoma (CC-CS).

MATERIALS AND METHODS

Retrospective review of patients with CC-CS diagnosed between January 2007 and December 2019. Data collected included age, sex, skeletal location and the presence of pathological fracture at presentation. Histological tumour grade based on surgical resection or needle biopsy was classified as atypical cartilaginous tumour (ACT)/grade 1 CS (ACT/Gd1 CS), high-grade CS (HG-CS) and dedifferentiated CS (DD-CS). The presence of pathological fracture was correlated with age, skeletal location and tumour grade.

RESULTS

Three hundred seventeen patients were included (177 males and 140 females with mean age 55.8 years, range 9-91 years). Mean age of patients without pathological fracture was 54.4 years and those with pathological fracture 62.9 years (p = 0.002). The major long bones were involved in 171 cases, the flat bones in 112 cases, the mobile spine in 7 cases and the small bones of the hands and feet in 27 cases. There were 81 ACT/Gd 1 CS, 168 HGCS and 68 DD-CS. Pathological fracture was evident at presentation in 51 (16.1%) cases, the commonest bones involved being the femur (n = 21; 41.2%), humerus (n = 10; 19.6%) and acetabulum (n = 7; 13.7%). Pathological facture occurred in 7 cases of ACT/Gd 1 CS (13.7%), 23 cases of HGCS (45.1%) and 21 cases of DD-CS (41.2%) (p = 0.001). Following multivariate analysis, both older age and histological grade were independently significant factors.

CONCLUSIONS

Pathological fracture was seen in 16.1% of patients with CC-CS. Pathological fractures in the femur, humerus and acetabulum very likely indicate higher tumour grade.

Natural history of the cervical high-intensity intramedullary lesion in achondroplasia

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The cervical high-intensity intramedullary (CHII) lesion is a recognised finding in achondroplasia, manifesting as a focal area of increased T2W signal intensity in the upper cervical cord in the absence of cervical cord compression. The aim of this study is to determine the natural history of this abnormality.

SETTING

Tertiary referral spinal and orthopaedic hospital, UK.

METHODS

A retrospective review was undertaken of all patients with achondroplasia who had undergone at least one MRI study which included the cervical spine. Patient age at presentation was recorded and presence of the CHII lesion was determined on the sagittal T2W FSE sequence. For patients who had follow-up studies, presence of the CHII lesion was assessed for any change in morphology (resolution, partial resolution or enlargement). The development of new CHII lesions and presence of associated cord atrophy was also recorded.

RESULTS

The study group consisted of 40 patients (20 males, 20 females: mean age at first MRI of 32.6 years (range 7-66 years). The CHII lesion was identified in 19 (47.5%) cases and was associated with focal cord atrophy in 17 (85%) cases. There was no change or resolution of these lesions nor any associated cord compression. No new CHII lesions developed but progressive cord atrophy was evident.

CONCLUSION

The CHII lesion is seen in 47.5% of cases of achondroplasia. It appears to be a stable abnormality which does not progress or change its morphology. However, it does appear to be associated with progressive cord atrophy.

Comparison of lumbar degenerative disc disease using conventional fast spin echo T2W MRI and T2 fast spin echo dixon sequences

OBJECTIVES

To compare the grading of lumbar degenerative disc disease (DDD), Modic end-plate changes (MEPC) and identification of high intensity zones (HIZ) on a combination of sagittal T₁weighted turbo spin echo (T₁W TSE), T₂weighted fast spin echo (T₂W FSE) and short tau inversion recovery (STIR) sequences (routine protocol) with a single sagittal T₂W FSE Dixon MRI sequence which provides in-phase, opposed-phase, water only and fat only images in a single acquisition (Dixon protocol).

METHODS

50 patients underwent lumbar spine MRI using the routine protocol with the addition of a T₂W FSE Dixon sequence. DDD grade, MEPC and HIZ for each disc level were assessed on the routine and Dixon protocols. Each protocol was reviewed independently by three readers (consultant musculoskeletal radiologists with 26-, 8- and 4 years' experience), allowing assessment of inter-reader agreement and inter protocol agreement for each assessed variable.

RESULTS

The study included 17 males and 33 females (mean age 51 years; range 8-82 years). Inter-reader agreement for DDD grade on the routine protocol was 0.57 and for the Dixon protocol was 0.63 (p = 0.08). Inter-reader agreement for MEPC on the routine protocol was 0.45 and for the Dixon protocol was 0.53 (p = 0.02), and inter-reader agreement for identification of the HIZ on the routine protocol was 0.52 and for the Dixon protocol was 0.46 (p = 0.27). Intersequence agreement for DDD grade ranged from 0.61 to 0.97, for MEPC 0.46-0.62 and for HIZ 0.39-0.5.

CONCLUSION

A single sagittal T₂W FSE Dixon MRI sequence could potentially replace the routine three sagittal sequence protocol for assessment of lumbar DDD, MEPC and HIZ resulting in ~60% time saving.

ADVANCES IN KNOWLEDGE

Grading of lumbar DDD, presence of Modic changes and high intensity zones were compared on sagittal T₁W TSE, T₂W FSE and STIR sequences with a T₂W FSE Dixon sequence, with fair-to-good correlation suggesting that three conventional sequences could be replaced by a single Dixon sequence.

Dermatofibrosarcoma protuberans: the diagnosis of high-grade fibrosarcomatous transformation

OBJECTIVES

Dermatofibrosarcoma protuberans (DFSP) is an intermediate-grade tumour which may undergo fibrosarcomatous transformation to a high-grade sarcoma (DFSP-FST). DFSP-FST requires wide local resection, and therefore, pre-operative identification is important. The aims of this study are to see if DFSP and DFSP-FST can be differentiated based on MRI appearances, and to determine the ability of ultrasound-guided core needle biopsy (US-CNB) to identify DFSP-FST.

MATERIALS AND METHODS

Retrospective review of patients with a histological diagnosis of DFSP with/without transformation to DFSP-FST. Patient age, gender, lesion location and maximal size were recorded, as were several MRI features. MRI studies were reviewed independently by 2 musculoskeletal radiologists and the assessed features were then compared with final surgical resection histology. Histological results of US-CNB were also compared with final surgical pathology.

RESULTS

A total of 42 patients were included, 26 males and 16 females with a mean age of 41.3 years (range 3-78 years). The upper limb was involved in 12 cases, the lower limb in 17 and the trunk in 13. Final surgical histological diagnosis was DFSP in 21 (50%) cases and DFSP-FST in 21 (50%) cases. Mean tumour dimension for DFSP was 32 mm and DFSP-FST 68 mm (p < 0.001). MRI features indicative of DFSP-FST included multi-lobular morphology (p = 0.03), T2W hypointensity compared with fat (p = 0.03), internal flow voids (p = 0.03) and peri-tumoral oedema (p < 0.001). Only 3 cases of DFSP-FST were correctly diagnosed on US-CNB.

CONCLUSIONS

Various MRI findings can suggest a diagnosis of DFSP-FST, but US-CNB is unreliable at identifying high-grade fibrosarcomatous transformation.

The differential diagnosis of trunk and extremity dermal and sub-dermal lesions referred to a musculoskeletal oncology service

OBJECTIVES

To determine the differential diagnosis of dermal and sub-dermal soft tissue masses which do not extend to the deep fascia that are referred to a specialist musculoskeletal oncology service.

MATERIALS AND METHODS

Review of all patients referred to a specialist musculoskeletal oncology service over a 13-month period with a dermal or sub-dermal soft tissue mass which did not extend to the deep fascia based on MRI appearances. Data collected included age, gender, site and maximal lesion size, and final histological diagnosis for biopsied and/or excised lesions.

RESULTS

56 patients were included, 21 (37.5%) males and 35 (62.5%) females with mean age 49.75 years (range 5-86 years). 3 patients had 2 lesions making a total of 59 lesions, 11 (18.6%) dermal and 48 (81.4%) sub-dermal. Histological diagnosis was available in 44 (74.6%) cases, of which 11 (25%) were non-neoplastic, 23 (52.3%) were benign neoplasms, and 10 (22.7%) were malignant neoplasms. Although older age at presentation and greater mean maximal tumour dimension were seen with malignant lesions, these did not reach statistical significance (p = 0.154 and 0.102 respectively). There was also no relationship between skin involvement from sub-dermal lesions and malignancy, but 5 of 6 dermal lesions which showed an exophytic growth pattern were malignant.

CONCLUSIONS

The differential diagnosis of dermal and sub-dermal lesions which do not reach the deep fascia is wide with a malignant lesion being the cause in almost one-quarter of cases.

The importance of MRI review following the diagnosis of atypical cartilaginous tumour using image-guided needle biopsy

OBJECTIVE

To evaluate the role of pre-biopsy MRI for management planning in patients with atypical cartilaginous tumours (ACT) diagnosed on image-guided core needle biopsy (IGCNB).

MATERIALS AND METHODS

Retrospective review of patients diagnosed with ACT of the appendicular skeleton based on IGCNB who subsequently underwent surgical curettage or resection. Data collected included age, sex, skeletal location and surgical histology classified as ACT, high-grade chondrosarcoma (HG-CS) and dedifferentiated chondrosarcoma (DD-CS). Pre-biopsy MRI studies were reviewed independently by 2 radiologists blinded to surgical histology results and graded as ACT, HG-CS and DD-CS based on MRI features.

RESULTS

The study included 24 males and 28 females (mean age 42.1 years; range 9-76 years). One patient had 2 lesions treated, making a total of 53 lesions. Tumours were located in the femur in 21 cases, humerus in 17, tibia in 9, radius in 4 and ulna and fibula in 1 each. Surgical histology was ACT in 41 cases, HG-CS in 10 and DD-CS in 2, indicating mismatch between IGCNB and surgical histology in 12/53 cases (22.6%). Predicted MRI grade for the 2 readers was ACT in 39 cases each, HG-CS in 13 and 14 cases and DD-CS in 1 and 0 cases. Sensitivity, specificity and accuracy of MRI for predicting HG-CS/DD-CS were 91%, 93% and 92%, respectively. Inter-observer correlation was very good (kappa = 0.94).

DISCUSSION

Review of MRI findings in patients with ACT diagnosed on IGCNB is vital for identifying patients with a HG-CS/DD-CS and is recommended when planning surgical management or considering repeat IGCNB.

Increased heart rate with sleep disordered breathing in hypertrophic cardiomyopathy

BACKGROUND

Current guidelines recommend medications with rate control properties for symptomatic patients with hypertrophic cardiomyopathy (HCM) based on the rationale that lowering heart rate (HR) improves their symptoms. Whether sleep disordered breathing (SDB) is associated with increased HR in HCM patients is not known.

METHOD

We diagnosed uncontrolled SDB (oxygen desaturation index ≥5) in consecutive echocardiographically confirmed HCM patients seen at Mayo Clinic, Rochester, and analyzed their HR as recorded by a 24-h Holter monitor. We compared mean, minimum, maximum HR between those with vs without SDB. In a pilot subanalysis of HCM patients with SDB who also underwent subsequent diagnostic polysomnography (PSG), we analyzed RR interval changes coinciding with obstructive sleep apnea and hypopnea episodes.

RESULTS

Of the 230 HCM patients included in this study (age 54 ± 16 years; 138 male; LVOT pressure gradient at rest 45 ± 39 mmHg), 115 (50%) patients had SDB. HCM patients with SDB were recorded to have higher mean HR (71 vs. 67 bpm; p = .002, adjusted p = .001), and this difference was most pronounced during night hours of 10 PM to 5 AM (61 vs. 67 bpm; p < .001). In the pilot analysis of the available PSG data, the release of obstructive sleep apneas and hypopneas coincided with fluctuation of HR.

CONCLUSIONS

SDB is independently associated with higher mean HR in patients with HCM, and this difference is most significant during sleep. Treatment of SDB, which is readily available, should be tested as a complementary modality to the currently recommended pharmacotherapy aimed at lowering HR in patients with symptomatic HCM.

A review of staging chest CT in trunk and extremity soft tissue sarcoma

OBJECTIVES

To determine the incidence of pulmonary metastases on chest CT in trunk and extremity soft tissue sarcoma based on two size criteria, and to identify factors associated with metastases.

METHODS

Retrospective review of chest CT studies in patients with trunk and extremity soft tissue sarcoma over an 18-month period. Data collected included patient age/sex, tumour location, size and relationship to fascia. All chest CTs were reviewed for the presence of metastases which were diagnosed according to two size criteria: multiple nodules > 5 mm in size or multiple nodules > 10 mm in size. Follow-up CT studies were reviewed in cases initially considered indeterminate.

RESULTS

127 males and 73 females were included (mean age 57.1 years; range 10-90 years). 147 (73.5%) tumours were deep to the fascia and 53 (26.5%) superficial. Tumour size classified according to the 12 AJCC 2019 criteria was: T1 = 52, T2 = 76, T3 = 39, T4 = 33. Based on nodule size >5 mm, 73 (36.5%) patients had no metastases, 42 (21%) had metastases, while 85 (42.5%) studies were indeterminate. Based on nodule size >10 mm, 73 (36.5%) patients had no metastases, 28 (14%) had metastases, while 99 (49.5%) studies were indeterminate. Larger maximum dimension of the primary tumour was a risk factor for pulmonary metastases using both size criteria.

CONCLUSION

The incidence of pulmonary metastases at presentation in trunk and extremity soft tissue sarcoma is 14-21%. 42.5-49.5% of chest CTs were indeterminate.

ADVANCES IN KNOWLEDGE

The incidence of pulmonary metastases at presentation in trunk and extremity soft tissue sarcoma is 14-21%. Indeterminate pulmonary nodules are also very common.

Pilot study to differentiate lipoma from atypical lipomatous tumour/well-differentiated liposarcoma using MR radiomics-based texture analysis

AIMS

This pilot study aims to determine if tumour heterogeneity assessed using magnetic resonance imaging (MRI) radiomics-based texture analysis (TA) can differentiate between lipoma and atypical lipomatous tumour (ALT)/well-differentiated liposarcoma (WDL).

MATERIALS AND METHODS

Thirty consecutive ALT/WDLs and 30 lipomas were included in the study, cases diagnosed both histologically and with murine double minute 2 (MDM2) gene amplification by fluorescence in situ hybridisation (FISH) in excision specimens. Multiple patient, MRI and MRTA factors were assessed. Heterogeneity was evaluated using a filtration-histogram technique-based textural analysis on single axial proton density (PD) and coronal T1-W images of the most homogenously fatty component of the lesion.

RESULTS

Thirty-three percent of the diagnoses of ALT/WDL vs lipoma were confirmed using FISH MDM2 analysis. ALT/WDLs were statistically different from lipomas in location (site in the body and depth from skin surface) and fat content, with p values of 0.021, 0.001, and 0.021 respectively. Nine of 36 (25%) texture parameters had significant differences between ALT/WDLs and lipomas on axial PD MRTA, with the most significant results at medium and coarse texture scales particularly mean intensity (p = 0.003) at SSF = 6, and kurtosis (p = 0.012) at SSF = 5. A cut-off value of < 304 for coarse-filtered texture on axial PD MRI identified ALT from lipoma with a sensitivity and specificity of 70% (AUC = 0.73, p = 0.003).

CONCLUSIONS

Texture heterogeneity quantified at fine, medium, and coarse texture scales are significant differentiators of lipoma and ALT/WDL with the difference particularly marked in medium and coarse texture scales for two MR TA parameters: mean and kurtosis.

Accessory flexor carpi ulnaris: case report and review of the literature

Most of the accessory muscles of the forearm described in the radiology literature are located either in the radial aspect of the forearm or towards the hypothenar eminence. We present an unusual case of an ulnar-sided distal forearm accessory flexor carpi ulnaris muscle presenting as a “pseudotumour“ demonstrated with both ultrasound and MRI, rarely reported in the current surgical and anatomical literature. Given the location and relation to the ulnar nerve towards Guyon’s canal, the accessory muscle may also predispose to distal ulnar nerve entrapment.

The radiological diagnosis of extra-articular posteromedial talocalcaneal coalition

OBJECTIVES

Extra-articular posteromedial talocalcaneal coalition (EA-PM TCC) accounts for approximately one-third of TCC, but its radiographic features are not well-described. The current study aims to compare the radiographic features of EA-PM TCC with normal ankles and with the commoner forms of TCC.

MATERIALS AND METHODS

A retrospective review of cases of TCC over 12 years for whom radiographs, CT, and/or MRI study were available. Radiographs were assessed by 2 radiologists for the presence of the C-sign, talar beak, dysmorphic sustentaculum, absent middle facet, and prominence of the posterior subtalar joint. TCC was classified by a third radiologist based on CT/MRI findings into 3 groups: no TCC, EA-PM TCC, and other TCCs. The radiographic findings for the 3 groups were compared.

RESULTS

The study included 50 patients, 28 males and 22 females with a mean age of 21.1 years (range 8-70 years). In 15 patients, both ankles had been imaged, resulting in a total of 65 cases. In 17 ankles, no TCC was identified, while 15 ankles were classified as EA-PM TCC and 33 as having other types of TCC. There were no statistically significant differentiating radiological features between the groups with no TCC and EA-PM TCC apart from prominence of the posterior subtalar joint, while only the C-sign allowed identification of patients with other types of TCC.

CONCLUSIONS

The study suggests that EA-PM TCC cannot be diagnosed based on the classical indirect radiological signs of TCC, but can be identified by prominence of the posterior subtalar joint.

Description of the MRI and ultrasound imaging features of giant epidermal cysts

OBJECTIVES

Guidelines suggest that lesions over 5 cm in dimension should be referred to a specialist sarcoma centre due to the possibility of malignancy. Few epidermal cysts (ECs) reach or exceed this size and are termed giant ECs (GECs). The purpose of this study is to report on a large series of GECs.

METHODS

Retrospective review of histologically proven GECs over an 8-year period. Patient demographics with MRI and ultrasound (US) appearances were evaluated.

RESULTS

A total of 14 cases were included with eight males and six females. Mean age was 51 years. 11 lesions were oval and three bi-lobed in shape, while 12 demonstrated dermal apposition. All were hyperintense on water-sensitive sequences and isointense to slightly hypointense on T1W imaging. Internal clefts were seen in 13 cases and 11 demonstrated chemical shift artefact (CSA) on MRI. On US, 12 showed well-defined linear hypoechoic clefts, with 66.6% having dis-organised compared with 33.3% peripherally located clefts. One 'pseudo testis' pattern and one showing irregular striped echogenicity termed novel 'pseudo muscle' appearance. No cases demonstrated internal vascularity on Doppler US.

CONCLUSIONS

MRI signal findings of GECs are often characteristic with hyperintensity on water-sensitive sequences, dermal apposition, CSA and internal clefts while US features of disorganised or clumped hypoechoic clefts and absence of neovascularity were commonly seen. Recognition of combinations of both US and MRI features of GECs should reduce the requirement for pre-excisional needle biopsy to confirm the diagnosis.

ADVANCES IN KNOWLEDGE

1. Identification of common imaging features of GECs should avoid unnecessary pre-excisional biopsy despite their large size in the appropriate MDT setting.2. A novel 'pseudo-muscle' appearance is described on MRI and US.

Small indeterminate superficial soft tissue masses: relationship between depth and histological grade

OBJECTIVE

To determine whether the location of a small, indeterminate soft tissue mass within the subcutaneous compartment is related to its histological grade.

METHODS

All Sarcoma Service referrals over a 12 month period of small (<3 cm) superficial soft tissue masses, indeterminate by MRI evaluation which subsequently underwent primary excision biopsy were included. Lesions were categorised by their anatomical location in the subcutaneous compartment. Histopathological diagnoses were categorized according to12 WHO 2013. χ2 statistical analysis was performed to determine the relationship between lesion depth and histological grade.

RESULTS

The study included 43 patients, mean age 42 years (range 15-71 years). Within the subcutaneous compartment, 16 lesions were categorized as superficial, 9 lesions central and 18 lesions deep, of which 9 were non-neoplastic, 29 benign, 1 intermediate-grade and 4 malignant. Location in the deep aspect of the subcutaneous compartment was associated with a higher risk of intermediate or malignant histology (p = 0.02).

CONCLUSION

The location of a small, indeterminate soft tissue mass within the subcutaneous compartment may be an indicator of histological aggressiveness. Lesions in the deep subcutaneous compartment are more likely to be intermediate-grade/malignant lesions. Therefore, if considering excision biopsy as definitive treatment, a wider margin may be appropriate.

ADVANCES IN KNOWLEDGE

Small, indeterminate soft tissue masses can be aggressive and the anatomical depth within the subcutaneous tissue may be a potential indicator of histological aggressiveness.

The incidence and diagnostic relevance of chemical shift artefact in the magnetic resonance imaging characterisation of superficial soft tissue masses

OBJECTIVE

Chemical shift artefact (CSA) is often encountered during MRI evaluation of superficial soft tissue masses. The study aim was to determine the incidence and diagnostic relevance of CSA in a consecutive series of superficial soft tissue masses referred to a specialist musculoskeletal sarcoma service.

METHODS

All patients referred over a 6 month period with a non-lipomatous superficial soft tissue mass were prospectively analysed. Patients characteristics (age, gender), lesion features (anatomical location, size, relationship to the skin and deep fascia), presence of CSA and final histopathological diagnosis were collected. The presence of CSA was statistically analysed against these clinical, imaging and histopathological variables.

RESULTS

128 patients fulfilled the inclusion criteria [63 males, 65 females; mean age = 50.6 years (7-96 years)]. CSA was present in 50 cases (39.1%) overall, but in 39 (41.5%) of 94 cases with histological diagnosis. There was no statistically significant relationship to any assessed variable apart from relationship to the deep fascia, CSA being more frequent in lesions contacting the fascia compared to lesions contacting both skin and fascia (p-value 0.02). In particular, the presence of CSA did not allow differentiation between non-malignant and malignant lesions.

CONCLUSION

The presence of CSA is a not infrequent finding in the MRI assessment of superficial soft tissue masses but does not appear to be of any significance in differentiating between non-malignant and malignant lesions.

ADVANCES IN KNOWLEDGE

CSA is a relatively common finding in association with superficial soft tissue masses, but does not indicate a particular histological diagnosis or help in the differentiation of non-malignant from malignant lesions.

P4415Long obstructive sleep apneas as a biomarker of atrial fibrillation

Background

Even though obstructive sleep apnea (OSA) is strongly associated with atrial fibrillation (AF), the use of traditional OSA scoring by apnea hypopnea index (AHI) did not result in improved arrhythmia outcomes in recent randomized trials. Longer OSA episodes lead to stronger pro-arrhythmic changes, and whether very long OSA episodes are more prevalent in AF patients remains unknown.

Purpose

We hypothesized that AF patients with mild-moderate OSA manifest greater percentage of long (>20s), very long (>30s), and extremely long (>40s) OSA episodes, compared to control OSA patients matched to AHI, age and sex.

Methods

From patients studied with diagnostic polysomnography in our laboratory between 2016 and 2018, we selected 22 patients with mild-moderate untreated OSA of which 11 patients had history of paroxysmal AF and 11 patients did not have any cardiac history. The length, oxygen desaturation, and relationship to neighboring events was manually re-measured in all recorded apnea and hypopnea events.

Results

In the 22 included patients (age 62.5±9.1 years, AHI 12.8±6.1, 40% female) we recorded 1021 apneas: 508 in the AF group and 513 in the control group. AF patients had longer apneas compared to the patients without AF history (mean length 28.7±11.7s vs. 23.3±9.9s; p<0.0001). The proportion of apneas that were long (>20s), very long (>30s), and extremely long (>40s) was greater in the AF group as compared to the control (p=0.0039, p=0.0215, p=0.0104, respectively; see figure). The acute oxygen saturation drops (>2%) during apneas were comparable between the AF group and control groups (p=0.13), but the long (>20s) apneas were prone to greater oxygen desaturations.

Length of Apneas

Conclusions

While traditional scoring of OSA focuses on episodes lasting >10s, our data newly show that longer durations of OSA events are particularly prevalent in AF patients. These results, combined with recent mechanistic studies showing that longer apneas exert greater pro-arrhythmic effect on atrial conduction, suggest that novel scoring of OSA placing more weight on longer apneas should be explored, especially when screening and titrating OSA therapy in patients at risk of AF.

Association between REM sleep and obstructive sleep apnea in obese and overweight adolescents

PURPOSE

Overweight and obese children have demonstrated reduced rapid eye movement (REM) sleep, affecting energy balance regulation and predisposition to weight gain. Obstructive sleep apnea (OSA) is a known cause of decreased REM sleep. The purpose of this study is to examine the association between the percentage of REM sleep, BMI z-score, and OSA severity in overweight and obese adolescents.

METHODS

We performed a cross-sectional study of 92 (43% female) overweight and obese adolescents (13-17 years old) who underwent overnight polysomnography (PSG) at Children's Hospital Los Angeles between 2010 and 2017.

RESULTS

The average Body Mass Index (BMI) z-score was 2.27 ± 0.47, with 71% having BMI z-score ≥ 2. REM% during PSG was 15.6 ± 6.8, and obstructive apnea-hypopnea index was 17.1 ± 24.3. The distribution across categories of OSA severity was 27% none (≤ 1.5 events/h), 24% mild (> 1.5-5 events/h), 8% moderate (> 5-10 events/h), and 41% severe (> 10 events/h). REM% was not associated with BMI z-score, either on univariate or multivariate regression with adjustment for age, gender, and apnea-hypopnea index (AHI). When subdivided into OSA categories, a 1-unit increase in BMI z-score was associated with a 5.96 (p = 0.03) increase in REM% in mild OSA and an 8.86 (p = 0.02) decrease in REM% in severe OSA. There was no association between BMI z-score and REM% in none and moderate OSA.

CONCLUSION

Among overweight and obese adolescents, BMI z-score was associated with decreased REM% in severe OSA and unexpectedly increased REM% in mild OSA, but there was no association in none or moderate OSA.

Small, superficial, indeterminate soft-tissue lesions as suspected sarcomas: is primary excision biopsy suitable?

OBJECTIVE

Suspected soft-tissue sarcomas are typically investigated using magnetic resonance imaging (MRI), with a view to planning image-guided core needle biopsy for confirmation of the histological diagnosis. Indeterminate superficial lesions may be small and therefore potentially difficult to biopsy safely, such lesions possibly being more amenable to primary excision biopsy. The aim of this study is to determine the suitability of this practice in the setting of a specialist sarcoma service.

MATERIALS AND METHODS

All patients referred over a 12-month period to the sarcoma service with a small (<3-cm), indeterminate, superficial soft-tissue mass according to MRI criteria, or a small lesion of the hand or foot deemed unsafe for percutaneous biopsy, and who underwent primary excision biopsy were included. The histology results were categorized into neoplastic and non-neoplastic lesions, and assessed for resection completeness.

RESULTS

Fifty-eight patients fulfilled the inclusion criteria from all patients referred to the sarcoma service in a 12-month period. Of these, 42 out of 58 (72.4%) had benign neoplasms, 4 out of 58 (6.9%) had malignant tumours, 2 out of 58 (3.4%) an intermediate grade lesion, while 10 out of 58 (17.2%) were non-neoplastic. All 4 malignant lesions were completely excised at the time of excision biopsy.

CONCLUSIONS

Primary excision biopsy of small, indeterminate soft-tissue masses within the setting of a specialist sarcoma service is a suitable management option. Only a small proportion of small superficial soft-tissue lesions with indeterminate MRI features are malignant tumours.

Imaging of the Painful Hip Arthroplasty

The incidence of complications following total hip arthroplasty is low, but due to the frequency of the procedure, they are quite commonly encountered and require appropriate investigation. Complications include aseptic loosening, infection, foreign body granulomatosis (osteolysis), adverse reactions to metal debris, periprosthetic fracture, heterotopic ossification, hardware failure, and a range of soft tissue complications, all of which may result in pain. Relevant imaging findings are illustrated and the role of various imaging modalities is reviewed. A suggested approach for the radiological investigation of each potential complication is outlined, based on our experience at a specialist referral unit.

Intracortical intraosseous lipoma

Intraosseous lipomas are very uncommon, benign primary bone lesions with an incidence of <1%. The overwhelming majority occur within the intramedullary canal. We present an uncommon intracortical intraosseous lipoma with 3 T MRI findings to help differentiate this from other differential diagnoses.

Melanotic schwannoma: an 11-year case series

Melanotic or melanocytic schwannoma is a rare tumour usually involving spinal nerve roots but can also present at other anatomical locations. Although there are less than 200 cases reported, melanotic schwannomas can have distinctive imaging features but there is limited recent literature on its often characteristic radiological appearances. Recent publication of the largest case series thus far has suggested melanotic schwannoma to be a separate entity to other schwannomata and that its reclassification to a malignant lesion be under consideration. We present a case series over an 11-year period to highlight salient imaging features with reference to the current concerns regarding its malignant potential.

Superior mesenteric artery syndrome - A rare presentation and challenge in spinal cord injury rehabilitation: A case report and literature review

BACKGROUND

Obstruction of the third part of the duodenum (D3) is a very rare cause of gastric outflow obstruction. Rapid weight loss is the biggest risk factor. Patients seen in acute rehabilitation settings, not uncommonly, have a period of rapid weight loss. We report two cases of superior mesenteric artery (SMA) syndrome and review the literature.

CLINICAL DETAILS

The patients presented differently, one with repeated, refractory autonomic dysreflexia and severe spasticity and one with nausea, abdominal discomfort, and vomiting. CT abdomen with contrast identified dynamic duodenal (D3) obstruction against the posterior structures by narrow angled SMA, gastric distension and, in one case, dilation of the left renal vein. Both patients responded well to optimizing nutrition in different ways. Surgery was successfully avoided.

DISCUSSION

SMA syndrome is an atypical cause of high intestinal obstruction, frequently occurring in patients who have had rapid weight loss during spinal cord injury (SCI) rehabilitation. It may co-exist with left renal vein dilation "nutcracker phenomena". The associated neurogenic bowel dysfunction due to the nature of SCI could possibly contribute to delay in diagnosis.

CONCLUSION

Clinicians should consider the risk of SMA syndrome in patients with SCI with rapid weight loss. Early diagnosis is possible by doing a CT abdomen with contrast and angiography if there is a high index of suspicion. SMA syndrome can be successfully treated by aggressive nutritional management. This may include total parenteral nutrition or feeding by a nasojejunal tube. Duodenojejunostomy could be required in refractory cases.

Muscle atrophy and metal-on-metal hip implants: a serial MRI study of 74 hips

BACKGROUND AND PURPOSE

Muscle atrophy is seen in patients with metal-on-metal (MOM) hip implants, probably because of inflammatory destruction of the musculo-tendon junction. However, like pseudotumors, it is unclear when atrophy occurs and whether it progresses with time. Our objective was to determine whether muscle atrophy associated with MOM hip implants progresses with time.

PATIENTS AND METHODS

We retrospectively reviewed 74 hips in 56 patients (32 of them women) using serial MRI. Median age was 59 (23-83) years. The median time post-implantation was 83 (35-142) months, and the median interval between scans was 11 months. Hip muscles were scored using the Pfirrmann system. The mean scores for muscle atrophy were compared between the first and second MRI scans. Blood cobalt and chromium concentrations were determined.

RESULTS

The median blood cobalt was 6.84 (0.24-90) ppb and median chromium level was 4.42 (0.20-45) ppb. The median Oxford hip score was 34 (5-48). The change in the gluteus minimus mean atrophy score between first and second MRI was 0.12 (p = 0.002). Mean change in the gluteus medius posterior portion (unaffected by surgical approach) was 0.08 (p = 0.01) and mean change in the inferior portion was 0.10 (p = 0.05). Mean pseudotumor grade increased by 0.18 (p = 0.02).

INTERPRETATION

Worsening muscle atrophy and worsening pseudotumor grade occur over a 1-year period in a substantial proportion of patients with MOM hip implants. Serial MRI helps to identify those patients who are at risk of developing worsening soft-tissue pathology. These patients should be considered for revision surgery before irreversible muscle destruction occurs.

Clinical Usefulness of SPECT-CT in Patients with an Unexplained Pain in Metal on Metal (MOM) Total Hip Arthroplasty

SPECT-CT is increasingly used to assess painful knee arthroplasties. The aim of this study was to evaluate the clinical usefulness of SPECT-CT in unexplained painful MOM hip arthroplasty. We compared the diagnosis and management plan for 19 prosthetic MOM hips in 15 subjects with unexplained pain before and after SPECT-CT. SPECT-CT changed the management decision in 13 (68%) subjects, Chi-Square=5.49, P=0.24. In 6 subjects (32%) pain remained unexplained however the result reassured the surgeon to continue with non-operative management. SPECT-CT should be reserved as a specialist test to help identify possible causes of pain where conventional investigations have failed. It can help reassure surgeons making management decisions for patients with unexplained pain following MOM hip arthroplasty.

A new approach to managing patients with problematic metal hip implants: the use of an Internet-enhanced multidisciplinary team meeting: AAOS exhibit selection

BACKGROUND

Over one million patients worldwide are estimated to have a metal-on-metal hip arthroplasty. To improve the management of these patients and reduce surgeon uncertainty regarding decision-making, we designed an Internet-enhanced multidisciplinary team (iMDT) working approach.

METHODS

From August 2012 to April 2014, the iMDT discussed 215 patients with 266 metal-on-metal hip arthroplasties. Of these, 236 primary arthroplasties (132 hip resurfacing and 104 total hip) were analyzed. The remaining thirty cases involved problematic revised hips and were therefore excluded. The possible recommendations of the iMDT were monitoring, further investigation, or surgery. The concordance between the recommendation and the actual management was used to assess the usefulness of this approach in reducing uncertainty in surgeon-level decision-making.

RESULTS

The median Oxford Hip Score was 35 (range, 4 to 48), and median cobalt and chromium levels in whole blood were 3.54 ppb (range, 0.18 to 161.46 ppb) and 3.17 ppb (range, 0.20 to 100.67 ppb), respectively. Magnetic resonance imaging revealed abductor muscle atrophy in ninety-two (39%) of the hips and a pseudotumor in eighty (34%). The iMDT recommended monitoring of 146 (61.9%) of the hips, further investigation of thirty (12.7%), and surgery in sixty (25.4%). The actual outcome was concordant with the recommendation in 211 (91.7%) of the hips.

CONCLUSIONS

Our iMDT approach to the metal-on-metal hip burden combines the tacit knowledge of an expert panel, regulatory guidance, and up-to-date evidence to improve decision-making among surgeons. The high level of concordance between the recommendation and the actual outcome, combined with the feasibility of the methods used, suggest that this method effectively reduces uncertainty among surgeons and may lead to improved patient outcomes.

Automatic scoring of sleep stages and cortical arousals using two electrodes on the forehead: validation in healthy adults

Accuracy and limitations of automatic scoring of sleep stages and electroencephalogram arousals from a single derivation (Fp1 -Fp2 ) were studied in 29 healthy adults using a portable wireless polysomnographic recorder. All recordings were scored five times: twice by a referent scorer who viewed the standard polysomnographic montage and observed the American Academy of Sleep Medicine rules (referent scoring and blind rescoring); and once by the same scorer who viewed only the Fp1 -Fp2 signal (alternative scoring), by another expert from the same institution, and by the algorithm. Automatic, alternative and independent expert scoring were compared with the referent scoring on an epoch-by-epoch basis. The algorithm's agreement with the reference (81.0%, Cohen's κ = 0.75) was comparable to the inter-rater agreement (83.3%, Cohen's κ = 0.78) or agreement between the referent scoring and manual scoring of the frontopolar derivation (80.7%, Cohen's κ = 0.75). Most misclassifications by the algorithm occurred during uneventful wake/sleep transitions, whereas cortical arousals, rapid eye movement and stable non-rapid eye movement sleep were detected accurately. The algorithm yielded accurate estimates of total sleep time, sleep efficiency, sleep latency, arousal indices and times spent in different stages. The findings affirm the utility of automatic scoring of stages and arousals from a single frontopolar derivation as a method for assessment of sleep architecture in healthy adults.

Patients with sickle cell anemia on simple chronic transfusion protocol show sex differences for hemodynamic and hematologic responses to transfusion

BACKGROUND

Chronic transfusion therapy (CTT) is a mainstay for stroke prophylaxis in sickle cell anemia, but its effects on hemodynamics are poorly characterized. Transfusion improves oxygen-carrying capacity, reducing demands for high cardiac output, while decreasing hemoglobin (Hb)S%, reticulocyte count, and hemolysis. We hypothesized that transfusion would improve oxygen-carrying capacity, but that would be counteracted by a decrease in cardiac output due to increased hematocrit (Hct) and vascular resistance, leaving oxygen delivery unchanged.

STUDY DESIGN AND METHODS

To test this hypothesis, we examined patients on CTT immediately before transfusion and again 12 to 120 hours after transfusion, using echocardiography and near infrared spectroscopy.

RESULTS

Comparable increases in Hb and Hct and decreases in reticulocyte count and HbS with transfusion were observed in all patients, but males had a larger rebound of HbS%, reticulocyte count, and free Hb levels between transfusions. In males, transfusion decreased heart rate by 12%, stroke volume by 15%, and cardiac index by 24% while estimates for pulmonary and systemic vascular resistance increased, culminating in 6% decrease in oxygen delivery. In contrast, stroke volume and cardiac index and systemic and pulmonary vascular resistance did not change in women after transfusion, such that oxygen delivery improved 17%.

CONCLUSION

In our sample population, males exhibit a paradoxical reduction in oxygen delivery in response to transfusion because the increase in vascular resistance is larger than the increase in oxygen capacity. This may result from an inability to adequately suppress their HbS% between transfusion cycles.

The development of the circadian heart rate rhythm (CHR) in Asian infants

OBJECTIVE

To test the hypothesis that term-born Asian infants, at reduced risk to die of Sudden Infant Death Syndrome (SIDS) exhibit a circadian heart rate rhythm (CHR) at a later age than non-Asian term infants.

METHOD

Repeated overnight heart rate (HR) traces obtained with a battery-operated Polar S810i heart-rate monitor at home in 17 Asian Torajan infants in Indonesia, were compared with those of 52 non-Asian infants monitored as part of the Collaborative Home Infant Monitoring Evaluation (CHIME). HR was determined using a moving window averaging technique. A comparison of median HR during quiet sleep (QS) episodes (identified by minimum HR variability), established the presence of CHR.

RESULTS

Seventy three percent of non-Asian CHIME infants ≤7 weeks exhibited CHR compared to 45% of Asian Torajan infants. Between 8 and 12 weeks, 94% of non-Asian CHIME infants exhibited CHR, compared to 33% of Asian Torajan infants (p<0.001). Forty seven and 56% of Asian Torajan infants exhibited the CHR at the age intervals of 16-20 weeks and 21-25 weeks respectively. Active wakefulness percentages as a function of the entire recording and median QS HR were not significantly different in the two groups.

CONCLUSION

Despite the fact that Asian Torajan infants were on average a week older than non-Asian CHIME babies, between two and three months of age only one in three exhibited the CHR, compared to virtually all non-Asian CHIME infants. We speculate that the cause of this difference rests in the infants' environment rather than their genetic origin.

Index proposal and basic estimator study for quantification of oscillation of the secondary flow pattern in tortuous vessels

The development of atherosclerosis has been shown to correlate with regions of low wall shear stress and seemingly reduced mass transport. The local tortuosity of the arteries and local secondary flow oscillation also seem to be negatively correlated with the local occurrence of the disease. However there is currently no tool or physiological parameter that can be measured non-invasively to assess the local oscillation of the flow. Standard Colour Doppler imaging of secondary flow patterns during the blood pulse is studied and illustrated, and the local oscillation of the secondary flow pattern is proposed as an index, which could be an indicator of the likelihood of future disease development. Preliminary results are presented using a basic estimator developed for the proof of concept in the case of swirling flow, and based on colour-coded video signals collected in different configurations. In vitro results show that there is a correspondence between the Doppler patterns and the secondary flow patterns, the repeatability of the measures, and that the proposed index and its estimator reflect a joint influence of the local oscillation of the secondary flow pattern and of the flow rate. On another hand, while in vivo results still suffer from instabilities, noise and from scanners and processing limitations, they demonstrate that it is possible to use Colour Doppler imaging to image and characterize in vivo the secondary flow patterns and their oscillations non-invasively, and that it is possible for a trained clinician to perform manually such Doppler measurements for processing.

CXCR4 antagonists mobilize childhood acute lymphoblastic leukemia cells into the peripheral blood and inhibit engraftment

The role of CXCL12 in the bone marrow (BM) homing and growth of B-cell progenitor acute lymphoblastic leukemia (ALL) has been established. However, the effect of modulating CXCL12/CXCR4 interactions on the retention of ALL cells within the supportive BM microenvironment and the expansion and dissemination of ALL cells in vivo has not been examined. We used mouse models of human childhood and murine leukemia and specific peptide and small molecule CXCR4 antagonists to examine the importance of CXCL12/CXCR4 in the development of leukemia in vivo. CXCR4 antagonists mobilized ALL cells into the peripheral blood (PB). Extended administration of CXCR4 antagonists to mice with leukemia resulted in a reduction in the number of leukemic cells in the PB and spleens of animals compared to control treated animals in three of the five cases tested. There was also a marked reduction in the dissemination of ALL cells to extramedullary sites including liver and kidney in all cases where this occurred. Considering the inhibitory effect of stromal layers on the activity of chemotherapeutic agents and the interactive effect of CXCL12 antagonists with chemotherapeutic agents in vitro, this raises the possibility of using these agents to potentiate the effects of current chemotherapy regimens.

Retropharyngeal haemorrhage from a vertebral artery branch treated with distal flow arrest and particle embolisation

Retropharyngeal haematoma is a rare cause of rapid neck swelling that may result in fatal upper respiratory airway obstruction. Reported causes include trauma, surgery, retropharyngeal inflammation, carotid aneurysm, aberrant artery at the thoracic inlet and bleeding diathesis. We report a 90-year-old man who developed rapid and progressive neck swelling following a minor traumatic episode. Computed tomography showed a large low-density retropharyngeal haematoma extending from the skull base to the mediastinum, with suspected extravasation. The right vertebral artery angiogram confirmed contrast agent extravasation arising from a small branch artery. This was treated with temporary distal flow arrest and particle embolisation.

Effectiveness of bi-atrial pacing for reducing atrial fibrillation after coronary artery bypass graft surgery

Atrial fibrillation (AF) is common after cardiac surgery and adds significant cost and morbidity. The use of prophylactic pacing strategies to prevent post-operative AF has been controversial. We previously performed a pilot study which suggested that the combination of beta-blockers and bi-atrial pacing (BAP) may reduce AF after cardiac surgery. We prospectively randomized 118 patients to continuous BAP for up to 96 hours post-operatively versus standard therapy. All patients were treated with beta-blockers as tolerated. Patients were paced in the AAI mode at a rate of 100 pulses per minute. The primary endpoint of the study was the occurrence of sustained AF (>10 minutes). There was a significant reduction in the incidence of AF in the BAP group among patients undergoing coronary artery bypass graft surgery with or without aortic valve replacement (35 % vs. 19 % AF; OR=0.38, 95 % CI 0.15, 0.93; p <0.05). Including patients undergoing isolated aortic valve surgery (n=7), there remained a strong trend toward a reduction of AF with pacing (no atrial pacing [NAP] vs. BAP; 35 % vs. 21 % AF; OR=0.48, 95 % CI 0.21, 1.11; p=0.08). Patients age 70 or greater benefited most from pacing (NAP vs. BAP; 55 vs. 25 % AF; p<0.05), while those less than 70 years of age did not (17 vs. 18 % p=NS). There was a significant reduction in the amount of time spent in the intensive care unit among patients receiving BAP (50+/-40 vs. 37+/-25 h; p<0.05).BAP together with beta-blockade after coronary artery bypass graft surgery reduces the incidence of post-operative atrial AF. Elderly patients (age 70 or greater) appear to benefit most, and may be a group to whom this therapy should be targeted.

Gallstones implanting in the ovary. A complication of laparoscopic cholecystectomy

Laparoscopic cholecystectomy has become the treatment of choice for most patients with cholelithiasis. The spillage and loss of gallstones into the peritoneal cavity is a relatively common event occurring during these procedures and has generally been thought to be of little consequence. Although in many cases this does appear to be true, there are uncommon but nevertheless noteworthy sequelae being described. Complications reported have included intraperitoneal abscesses; foreign body granuloma formation; and, more rarely, cholelithiasis of the ovary. We present the case of a 30-year-old woman, who underwent diagnostic laparoscopy for infertility 20 months following a laparoscopic cholecystectomy. Gross findings showed tissue deposits that suggested a malignant tumor. Microscopic findings revealed gallstones embedded in the ovaries and the pelvic peritoneum. To our knowledge, this is the longest reported persistence of gallstones involving the ovary. A full case report is presented, and the possible complications of lost laparoscopic gallstones are reviewed.

Haemorrhagic cellulitis: a syndrome associated with tumour necrosis factor-alpha

A newly defined clinical syndrome, haemorrhagic cellulitis, is described in 12 patients. The syndrome consists of an acute onset of extremely painful erythema affecting dependent areas, followed by dermal haemorrhage and sloughing of the overlying epidermis, and requiring both antibiotics and systemic corticosteroids for complete resolution. The patients usually have demonstrable Gram-negative or Gram-positive infection, of non-cutaneous origin, and underlying systemic disease. Vacuolopathic necrosis of epidermal keratinocytes, and damaged vascular endothelium of the dermal blood vessels can be demonstrated by light and electron microscopy, as well as by lectin studies. Immunocytochemical studies reveal the presence of activated macrophages and T lymphocytes. We believe the syndrome is due to lipopolysaccharide-induced or bacterial mitogen-induced tumour necrosis factor-alpha (TNF-alpha), secreted by previously primed activated macrophages in a second-set response. TNF-alpha characteristically injures endothelial cells and epidermal keratinocytes. It is thought to induce its cytotoxic effects partly via neutrophil degranulation, and partly via DNAase activation, with resultant DNA fragmentation and cell lysis. Corticosteroids have been shown not only to inhibit TNF-alpha secretion by activated macrophages, but also to block its cytotoxicity, thus accounting for the extremely rapid clinical response to this drug in conjunction with adequate and appropriate antibiotic therapy.

Identification of low density lipoprotein as a regulator of Fc receptor-mediated phagocytosis

Optimal expression of the high-affinity Fc receptor for IgG (FcRI) by the human monocyte cell line U-937 requires the presence of low density lipoprotein (LDL), and neither cholesterol nor high density lipoprotein can provide the component necessary for optimal FcRI expression. Here we show that FcR-mediated phagocytosis also requires LDL. U-937 cells were cultured in medium containing interferon gamma and either fetal calf serum (FCS) or delipidated FCS (DLFCS). The phagocytosis of IgG-coated erythrocytes was measured by a colorimetric assay. U-937 cells cultured in DLFCS medium had less than 16% of the phagocytic activity of cells cultured in normal FCS medium. Phagocytosis of IgG-coated erythrocytes could be inhibited 85% by the addition of murine IgG2a myeloma protein (5 micrograms/ml). U-937 cells cultured in DLFCS medium supplemented with pure cholesterol in ethanol (10 micrograms/ml) had only 30% of the phagocytic activity of cells grown in FCS medium. Addition of very low density lipoprotein (0.2 mg of protein per ml) to DLFCS medium also failed to increase phagocytosis. However, the addition of LDL (0.2 mg of protein per ml) to DLFCS medium restored 90% of the phagocytic activity. Since neither pure cholesterol nor very low density lipoprotein restored normal phagocytic function to U-937 cells despite a normalization of cellular cholesterol content, the restoration of phagocytosis observed with LDL replacement cannot be explained by mere delivery of cholesterol by LDL. Thus, LDL is required for the expression of FcRI and FcR-mediated phagocytosis by U-937 cells and may be an important regulator of phagocytic activity of monocytes and macrophages in vivo.