An updated analysis on myocarditis and pericarditis cases reported following mRNA SARS-CoV-2 vaccination in Singapore.

INTRODUCTION: Messenger ribonucleic acid (mRNA) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been associated with myocarditis/pericarditis, especially in young males. We evaluated the risk of myocarditis/pericarditis following mRNA vaccines by brand, age, sex and dose number in Singapore. METHODS: Adverse event reports of myocarditis/pericarditis following mRNA vaccines received by the Health Sciences Authority from 30 December 2020 to 25 July 2022 were included, with a data lock on 30 September 2022. Case adjudication was done by an independent panel of cardiologists using the US Centers for Disease Control and Prevention case definition. Reporting rates were compared with expected rates using historical data from 2018 to 2020. RESULTS: Of the 152 adjudicated cases, males comprised 75.0%. The median age was 30 years. Most cases occurred after Dose 2 (49.3%). The median time to onset was 2 days. Reporting rates were highest in males aged 12-17 years for both primary series (11.5 [95% confidence interval [CI] 6.7-18.4] per 100,000 doses, post-Dose 2) and following booster doses (7.1 [95% CI 3.0-13.9] per 100,000 doses). In children aged 5-11 years, myocarditis remained very rare (0.2 per 100,000 doses). The reporting rates for Booster 1 were generally similar or lower than those for Dose 2. CONCLUSIONS: The risk of myocarditis/pericarditis with mRNA vaccines was highest in adolescent males following Dose 2, and this was higher than historically observed background rates. Most cases were clinically mild. The risk of myocarditis should be weighed against the benefits of receiving an mRNA vaccine, keeping in mind that SARS-CoV-2 infections carry substantial risks of myocarditis/pericarditis, as well as the evolving landscape of the disease.

Safety for cervical corpectomy and diskectomy: univariate and multivariate analysis on predictors for prolonged ICU stay after anterior spinal fusion.

AIM: Cervical anterior spinal fusion (ASF) with corpectomy has risks of catastrophic acute complications such as airway obstruction requiring re-intubation. Our team has adopted a management plan for all cervical corpectomy patients to be admitted to the intensive care unit (ICU) after the operations for overnight observation. Some of these patients were kept intubated after the operations and transferred to the ICU. This study aims to review the outcome of this practice and to identify independent predictors associated with a prolonged ICU stay. METHODS: We reviewed consecutive patients with cervical ASF from January 2010 to June 2018. The primary outcome was the ICU length of stay. Univariate and multivariate analyses were conducted to identify independent risk factors associated with a prolonged ICU stay. In total, 103 patients had ASF during the study period. ICU length of stay for elective ASF was 1.01 day (SD 0.373 days) and was significantly shorter than that for emergency ASF (13.29 days, SD 12.57 days) (p < 0.001). 79.6% (82/103) of the ASF patients were extubated in the operating theatre after surgery. Significantly more corpectomy patients (33.3%) versus ACDF patients (15.1%) were kept intubated to the ICU after the operation (p = 0.037). None required reintubation in the ICU. 90.9% (80/88) of the elective ASF can be discharged from the ICU within 24 hours and only 3.41% (3/88) of the elective ASF had prolonged post-operative stay in the ICU (≥48 hours). RESULTS: For prolonged postoperative ICU stay (≥48 hours), ICU admission airway status of ASF patients who were either extubated in the OT or kept intubated to ICU had no significant association (p = 0.903). Univariate and multivariate analysis had identified emergency admissions (p = 0.043) and the presence of postoperative neurological deficits (p = 0.031) as independent predictors associated with a prolonged postoperative ICU stay. CONCLUSION: In conclusion, cervical corpectomy and ASF were safe with minimal acute complications.

Blessing or burden? Long-term maintenance, complications and clinical outcome of intrathecal baclofen pumps.

AIM: The intrathecal baclofen pump is an effective treatment for spasticity. However, long-term results have reported patients' dissatisfaction and perception of disability. Potential causes include a frequent need for baclofen pump refill and risks of complications. The aim of the present study was to evaluate the long-term maintenance, complications and clinical outcome of intrathecal baclofen pumps. PATIENTS AND METHODS: We conducted a 16-year retrospective cohort study of patients with spasticity treated with an intrathecal baclofen pump at a university hospital from 2000 to 2016. The primary outcome was the rate of infection per puncture for baclofen pump refill. Secondary outcomes included the incidence of other complications, such as running out of baclofen causing symptomatic withdrawal symptoms, pump mechanical failure, pump battery end of life and the need for pump replacement. The clinical outcome was assessed by the Modified Ashworth Scale (mAS). RESULTS: In total, 340 follow-up episodes with pump refill procedures were recorded. The average interval between each pump refill was 57.3 days (±15.4 days). The average duration of admission for each pump refill was 4 h and 49 min (from 2 h 23 min to 10 h). There were two events with established infection after puncture for the refill, giving rise to an infection rate per puncture of 0.6 percent (2/340).For the long-term clinical outcome, at an average follow-up period of 7.6 years, the postoperative mAS for spasticity was 2.0 ± 0.756, which was significantly better than the preoperative mAS at 3.75 ± 0.462 (P = 0.001). CONCLUSION: Long-term aftercare with baclofen pump refill was safe, with an infection rate of 0.6 per cent per puncture for each refill. Long-term intrathecal baclofen pump was effective in the treatment of spasticity with persistent significant improvement in the spasticity scale.

Awake craniotomy for excision of arteriovenous malformations? A qualitative comparison study with stereotactic radiosurgery.

Treatment of arteriovenous malformations (AVM) located at the eloquent area has been a challenge. Awake brain mapping allows identification of a non-eloquent gyrus for intervention and can potentially facilitate resection with preservation of functions. An alternative treatment option is stereotactic radiosurgery (SRS). The objective of this study was to perform a qualitative comparison of the treatment outcome of awake AVM excision versus SRS. We conducted a 13-year retrospective review of AVM excision under awake craniotomy performed at Prince of Wales Hospital, Hong Kong, from 2003 to 2016. Patients' presentation, Spetzler-Martin (SM) grading, rate of obliteration and complication were reviewed and analyzed with the modified radiosurgery-based AVM score (RS score). Six patients had excision of AVM under awake mapping during this period of time. Two were SM Grade II and four were SM Grade III. Five located at the peri-rolandic region while one at the temporal language area. None had failed mapping. Five out of six achieved complete obliteration (83.3%). Qualitative comparative analysis had revealed better treatment outcome with awake AVM excision as compared to SRS with the obliteration rate of 100% versus 96% for RS score ≤1.00, 100% versus 78% for RS score 1.01-1.50, and 66% versus 50% for RS score >2.00 respectively. In conclusion, awake mapping and excision of AVMs at the eloquent area is feasible. Qualitative comparative analysis had revealed higher obliteration rate with awake AVM excision as compared to SRS.

Magnetic resonance microscopy may enable distinction between normal histomorphological features and prostate cancer in the resected prostate gland.

OBJECTIVES: To determine imaging protocol parameters for characterization of prostate tissue at histological length scales. MATERIAL AND METHODS: Rapid acquisition with relaxation enhancement, spin echo and gradient echo fast low angle shot data were acquired using ex vivo 3-Tesla or 7-Tesla magnetic field strengths from fresh prostatectomy specimens (n = 15) obtained from either organ donor or patients with prostate cancer (PCa). To achieve the closest correspondence between histopathological components and magnetic resonance imaging (MRI) results, in terms of resolution and sectioning planes, multiple high-resolution imaging protocols (ranging from a few minutes to overnight) were tested. Ductograms were generated as part of image post-processing. Specimens were subsequently submitted for histopathological evaluation. RESULTS: A total of seven imaging protocols were tested. Ex vivo 7-Tesla MRI identified normal components of prostate glands, including ducts, blood vessels, concretions and stroma at a spatial resolution of 60 × 60 × 60 µm3 to 107 × 107 × 500 µm3 . Malignant glands and nests of tumour cells identified at 60 × 60 × 90 µm3 were highly similar to low-magnification (×2) histopathology. Ductograms enhanced the differentiation between benign and malignant glands. The results of the present study were encouraging, and further work is warranted with a larger sample size. CONCLUSION: We showed that critical histopathological features of the prostate gland can be identified with high-resolution ex vivo MRI examination and this offers promise that MRI microscopy of PCa will ultimately be possible in vivo.

Long-term outcomes of laparoscopic adjustable gastric banding and laparoscopic Roux-en-Y gastric bypass in the United States.

BACKGROUND: Although laparoscopic adjustable gastric banding (LAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGB) are the most common bariatric procedures performed in the past decade, little is known about their long-term (>5 years) outcomes. METHODS: A retrospective outcome study investigated 148 consecutive patients from a single practice who underwent LAGB from November 2000 to March 2002. The group was matched with 175 consecutive patients who underwent LRYGB from June 2000 to March 2005. Follow-up data for 5 years or longer was available for 127 LAGB patients (86%) and 105 LRYGB patients (60%). RESULTS: After an initial 4 years of progressive weight loss, body mass index (BMI) loss stabilized at 5-7 years at approximately 15 kg/m(2) for the LRYGB patients and at about 9 kg/m(2) for the LAGB patients with band in place (P < 0.01). At 7 years, the excess weight loss (EWL) was 58.6% for LRYGB and 46.3% for LAGB with band in place (P < 0.01). By 7 years, 19 LAGB patients (15%) had had their bands removed, bringing the failure rate for LAGB (including patients with less than 25% EWL) to 48.3% versus 10.7% for LRYGB (P < 0.01). By 10 years, 29 (22.8%) of the bands had been removed, bringing the total LAGB failure rate to 51.1%. In 10 years, 67 LAGB (52.8%) and 43 LRYGB (41%) adverse events had occurred. However, over time, the LRYGB group experienced 9 (8.6%) serious, potentially life-threatening complications, whereas the LAGB group had none (P < 0.001). One procedure-related death occurred in the LRYGB group. CONCLUSIONS: Over the long term, LRYGB had an approximate reduction of 15 kg/m(2) BMI and 60% EWL, a significantly better outcome than LAGB patients experienced with band intact. The main issue with LAGB was its 50% failure rate in the long term, as defined by poor weight loss and percentage of band removal. Nevertheless, LAGB had a remarkably safe course, and it may therefore be considered for motivated and informed patients.

Doppler parameters in renal transplant dysfunction: correlations with histopathologic changes.

OBJECTIVES: The aim of this study was to assess the relationship between intrarenal Doppler parameters and histopathologic changes shown on kidney biopsy in renal transplant dysfunction. METHODS: We retrospectively reviewed the records of 113 patients (61 men and 52 women; age range, 22-76 years; mean age ± SD, 50.9 ± 12.7 years) who underwent both transplanted kidney sonography and biopsy from May 1, 2007, to May 31, 2009. Doppler parameters of the interlobar arteries, including the peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI), were compared with kidney biopsy findings. According to histopathologic findings, the 113 patients were divided into two groups: 1, interstitial fibrosis/tubular atrophy and vascular/glomerular sclerosis (n = 79); and 2, edematous changes in glomeruli without fibrosis (n = 34). The correlations between Doppler parameters and histopathologic findings were statistically analyzed. RESULTS: There were statistically significant differences in the PSV and EDV of the interlobar arteries between groups 1 and 2. Both the PSV and EDV in group 1 were significantly lower than those in group 2 (P < .001). There was no significant difference in the RI of the interlobar arteries between the two groups (P > .05). There were no significant differences in the PSV, EDV, and RI of the main renal artery between the two groups (all P > .05). CONCLUSIONS: The PSV and EDV of the interlobar artery have statistical correlations with histopathologic types in renal transplant dysfunction. Both the PSV and EDV in interstitial fibrosis/tubular atrophy and vascular/glomerular sclerosis seem lower than those in glomerulopathy without fibrosis. Hence, the PSV and EDV of the interlobar artery may potentially be used as hemodynamic indicators for monitoring the progress of renal transplants.

Flow turbulence or twinkling artifact? A primary observation on the intrarenal color Doppler sonography.

OBJECTIVE: The objective of this report was to describe and potentially explain differences of intrarenal color Doppler sonography (CDUS) manifestations between blood flow turbulence and twinkling artifact. METHODS: We retrospectively reviewed 32 cases with appearance of focally increased color Doppler signal on intrarenal CDUS from May 1, 2007, to February 28, 2009. Indications for intrarenal CDUS in 32 cases were suspicion of renovascular hypertension, investigation of complications related to renal biopsy, or hematuria. Characteristics of the color Doppler signal, relationship between color Doppler signal and renal vessels, and the spectral Doppler sampled at the anatomic site of the focal color signal were analyzed. The value and pitfall of color Doppler in the diagnosis of the intrarenal vascular abnormality and detection of renal calculus are discussed. RESULTS: Thirty-two cases with focally increased color Doppler during sonography of native or transplanted kidneys were classified into two groups: (1) turbulent blood flow-intrarenal vascular abnormalities including intrarenal arteriovenous fistula (15 cases) and intrarenal artery stenosis (eight cases); and (2) color Doppler artifact-twinkling produced by renal calculus (nine cases). There were differences in the characteristics of the color Doppler signal, the relationship between the color signal and renal vessel, and the spectral waveform on CDUS between flow turbulence and twinkling. CONCLUSION: Flow turbulence and twinkling artifact on intrarenal CDUS are distinguishable by analyzing the manifestations on intrarenal CDUS. Proper color Doppler setting and spectral Doppler play important roles in differentiation between flow turbulence in renal vascular abnormalities and twinkling produced by renal stones.

Color duplex sonography in severe transplant renal artery stenosis: a comparison of end-to-end and end-to-side arterial anastomoses.

OBJECTIVE: The aim of this study was to investigate differences in Doppler parameters between severe transplant renal artery stenosis (TRAS, arterial lumen reduction >80%) with end-to-end (EE) arterial anastomosis and that with end-to-side (ES) arterial anastomosis. METHODS: We retrospectively reviewed color duplex sonography (CDUS) and digital subtraction angiography (DSA) images in 38 patients with severe TRAS (19 cases with EE and 19 cases with ES) between January 1, 2000, and December 31, 2006. Doppler parameters were analyzed, including peak systolic velocity (PSV) in the iliac artery, PSV at the arterial anastomosis, PSV in the transplant renal artery, PSV ratio of the stenotic artery/artery proximal to the stenosis, and acceleration time (AT) in the artery distal to the stenosis (in the intrarenal artery). All 38 cases with severe TRAS were initially diagnosed with CDUS and confirmed by DSA. RESULTS: There were significant differences in PSV in the stenotic artery (P<.01), PSV in the iliac artery (P<.001), and PSV ratios of stenotic artery/artery proximal to the stenosis (P<.001) between arterial anastomosis of EE and that of ES. There was no statistically significant difference in AT in the intrarenal artery between the two types of anastomosis (P>.05). CONCLUSION: Significantly different PSVs in the stenotic artery, the iliac artery, and the PSV ratio between EE and ES arterial anastomoses should be considered in the interpretation of CDUS when screening for severe TRAS. Different criteria of CDUS need to be established depending on the type of arterial anastomosis in order to improve the accuracy in diagnosing severe TRAS.

Intrarenal color duplex ultrasonography: a window to vascular complications of renal transplants.

OBJECTIVE: We analyze and discuss the importance of intrarenal color duplex ultrasonography (CDUS) in the diagnosis and differential diagnosis of vascular complications in renal transplants. METHODS: We retrospectively reviewed results of CDUS, especially intrarenal CDUS, in 102 consecutive inpatients with vascular complications of renal transplants from January 1, 2000, to December 31, 2006. Correlations between CDUS and magnetic resonance angiography, digital subtraction angiography, surgical findings, and clinical diagnoses were studied. RESULTS: Abnormal findings on intrarenal CDUS clearly represent vascular complications primarily located at the main renal vessels and intrarenal vessels. In our study, there were 5 cases of false-negative intrarenal arteriovenous fistulas, 1 case of false-positive transplant renal vein thrombosis, and 2 cases of false-negative transplant renal artery stenosis. The accuracy of detecting vascular complications of renal transplants with CDUS was 92% (94/102). CONCLUSIONS: Intrarenal CDUS is a noninvasive, accurate diagnostic tool that can be administrated portably and is easily repeatable, thereby making it not only a highly valuable imaging technique but also the method of choice in screening and diagnosing vascular complications of renal transplants.

Innate host defense of the lung: effects of lung-lining fluid pH.

Lung-lining fluid (LLF) is a primary constituent of the pulmonary host defense system. It is distributed continuously throughout the respiratory tract but is heterogeneous regarding its chemistry and physiology between the conducting airways and alveoli. The conducting airways are lined with airway surface liquid (ASL), a mucus gel-aqueous sol complex that interacts functionally with epithelial cilia as the mucociliary escalator. The alveoli are lined with alveolar subphase fluid (AVSF) and pulmonary surfactant. AVSF sterility is maintained in part by the phagocytic activity of resident alveolar macrophages. Normal ASL and AVSF are both more acidic than blood plasma. However, the details of acid-base regulation differ between the two media. Appreciable transepithelial acid-base flux is possible across the airway epithelium, whereas the alveolar epithelium is relatively impermeable to transepithelial acid-base flux. Moreover, one must consider the influence of resident macrophages on AVSF pH. Resident macrophages occupy a sizable fraction of AVSF by volume and are a substantial source of metabolic H+. The buffering capacities of ASL and AVSF probably are largely due to secreted peptides (e.g., ASL mucins and AVSF surfactant proteins). Acid-base exchange between the extracellular hydrophase and intracellular buffering systems of resident macrophages represents an additional buffer pool for AVSF. The pH of ASL and AVSF can be depressed by disease or inflammation. Low pH is predicted to suppress microbe clearance from the airways and alveoli, increase pathogen survival in both regions, and alter mediator release by resident macrophages and recruited leukocytes thereby increasing the propensity for bystander cell injury. Overall, ASL/AVSF pH is expected to be a major determinant of lung host defense responses.