Prevalence of human papillomavirus in oral gargles and tonsillar washings

OBJECTIVES

Human papillomavirus (HPV) infection drives carcinogenesis in the oropharynx. No standard sampling or HPV detection methods for evaluating oropharyngeal HPV infection exist. The prevalence of oral HPV infection in Japan is unknown.

MATERIALS AND METHODS

We examined 435 healthy Japanese individuals to address whether adding tonsillar washing to oral gargling would improve HPV detection. We compared HPV assessment using GENOSEARCH HPV31 versus nested PCR and direct sequencing. Associations between HPV infection and demographic and behavioral characteristics were examined.

RESULTS

Most participants who were HPV-positive based on oral gargles were also HPV-positive based on tonsillar washings: 11 (64.7%) of 17 on nested PCR and 12 (70.6%) of 17 on GENOSEARCH HPV31. Although HPV infection was more prevalent in oral gargles followed by tonsillar washings than in oral gargles alone, the difference was not statistically significant (nested PCR, 4.8% vs. 3.9%, P = 0.46; GENOSEARCH HPV31, 5.3% vs. 3.9%, P = 0.33). The overall agreement between nested PCR and GENOSEARCH HPV31 was 98.6%, with 76.0% positive agreement. The overall prevalence of oral HPV infection in Japan was 5.7% (95% confidence interval, 3.9-8.3%). Men had a significantly higher prevalence of oral HPV infection than women (8.3% vs. 2.6%, P = 0.02). Infection increased with number of lifetime sexual partners (P < 0.001 for trend).

CONCLUSION

The oropharynx is probably the major source of HPV-infected cells in oral gargles. Oral gargling could be a standard sampling method for evaluating oropharyngeal HPV infection. GENOSEARCH HPV31 could be an option for oral HPV detection.

Role of Two Sets of RND-Type Multidrug Efflux Pump Transporter Genes, mexAB-oprM and mexEF-oprN, in Virulence of Pseudomonas syringae pv. tabaci 6605

Pseudomonas syringae pv. tabaci 6605 has two multidrug resistance (MDR) efflux pump transporters, MexAB-OprM and MexEF-OprN. To understand the role of these MDR efflux pumps in virulence, we generated deletion mutants, ∆mexB, ∆mexF, and ∆mexB∆mexF, and investigated their sensitivity to plant-derived antimicrobial compounds, antibiotics, and virulence. Growth inhibition assays with KB soft agar plate showed that growth of the wild-type (WT) was inhibited by 5 µl of 1 M catechol and 1 M coumarin but not by other plant-derived potential antimicrobial compounds tested including phytoalexins. The sensitivity to these compounds tended to increase in ∆mexB and ∆mexB∆mexF mutants. The ∆mexB∆mexF mutant was also sensitive to 2 M acetovanillone. The mexAB-oprM was constitutively expressed, and activated in the ∆mexF and ∆mexB∆mexF mutant strains. The swarming and swimming motilities were impaired in ∆mexF and ∆mexB∆mexF mutants. The flood inoculation test indicated that bacterial populations in all mutant strains were significantly lower than that of WT, although all mutants and WT caused similar disease symptoms. These results indicate that MexAB-OprM extrudes plant-derived catechol, acetovanillone, or coumarin, and contributes to bacterial virulence. Furthermore, MexAB-OprM and MexEF-OprN complemented each other's functions to some extent.

Risk model for severe postoperative complications after total pancreatectomy based on a nationwide clinical database

BACKGROUND

Total pancreatectomy is required to completely clear tumours that are locally advanced or located in the centre of the pancreas. However, reports describing clinical outcomes after total pancreatectomy are rare. The aim of this retrospective observational study was to assess clinical outcomes following total pancreatectomy using a nationwide registry and to create a risk model for severe postoperative complications.

METHODS

Patients who underwent total pancreatectomy from 2013 to 2017, and who were recorded in the Japan Society of Gastroenterological Surgery and Japanese Society of Hepato-Biliary-Pancreatic Surgery database, were included. Severe complications at 30 days were defined as those with a Clavien-Dindo grade III needing reoperation, or grade IV-V. Occurrence of severe complications was modelled using data from patients treated from 2013 to 2016, and the accuracy of the model tested among patients from 2017 using c-statistics and a calibration plot.

RESULTS

A total of 2167 patients undergoing total pancreatectomy were included. Postoperative 30-day and in-hospital mortality rates were 1·0 per cent (22 of 2167 patients) and 2·7 per cent (58 of 167) respectively, and severe complications developed in 6·0 per cent (131 of 2167). Factors showing a strong positive association with outcome in this risk model were the ASA performance status grade and combined arterial resection. In the test cohort, the c-statistic of the model was 0·70 (95 per cent c.i. 0·59 to 0·81).

CONCLUSION

The risk model may be used to predict severe complications after total pancreatectomy.

Requirement of γ-Aminobutyric Acid Chemotaxis for Virulence of Pseudomonas syringae pv. tabaci 6605

γ-Aminobutyric acid (GABA) is a widely distributed non-proteinogenic amino acid that accumulates in plants under biotic and abiotic stress conditions. Recent studies suggested that GABA also functions as an intracellular signaling molecule in plants and in signals mediating interactions between plants and phytopathogenic bacteria. However, the molecular mechanisms underlying GABA responses to bacterial pathogens remain unknown. In the present study, a GABA receptor, named McpG, was conserved in the highly motile plant-pathogenic bacteria Pseudomonas syringae pv. tabaci 6605 (Pta6605). We generated a deletion mutant of McpG to further investigate its involvement in GABA chemotaxis using quantitative capillary and qualitative plate assays. The wild-type strain of Pta6605 was attracted to GABA, while the ΔmcpG mutant abolished chemotaxis to 10‍ ‍mM GABA. However, ΔmcpG retained chemotaxis to proteinogenic amino acids and succinic semialdehyde, a structural analog of GABA. Furthermore, ΔmcpG was unable to effectively induce disease on host tobacco plants in three plant inoculation assays: flood, dip, and infiltration inoculations. These results revealed that the GABA sensing of Pta6605 is important for the interaction of Pta6605 with its host tobacco plant.

Prognostic impact of lymphovascular invasion in lymph node-negative superficial esophageal squamous cell carcinoma

The relationship between lymphovascular invasion (LVI) and prognosis in patients with superficial esophageal squamous cell carcinoma (SESCC) is unclear. The aim of this study is to evaluate prognostic factors in patients with lymph node-negative SESCC. A total of 195 patients with pathologically confirmed T1a-MM, T1b, and lymph node-negative SESCC were retrospectively reviewed in this study. Overall, the disease-free survival (DFS) rate was poorer in the lymphatic invasion-positive group than in the lymphatic invasion-negative group (p = 0.002) and a multivariate analysis suggested that lymphatic invasion was the only independent prognostic factor of DFS in patients with lymph node-negative SESCC (HR = 4.075, p = 0.005). Distant organ recurrence occurred in one patient (1/52, 1.9%) in the T1b-SM2 group and in six patients (6/61, 9.7%) in the T1b-SM3 group; all of these patients had LVI. LVI-positive patients had a poorer DFS than invasion-negative patients in the T1b-SM2 and SM3 groups (p = 0.026), and a multivariate analysis suggested that LVI was the only independent prognostic factor of DFS in patients with lymph node-negative SM2 and SM3 SESCC (HR = 5.165, p = 0.031). Lymph node-positive patients had a significantly poorer DFS rate than lymph node negative and LVI positive patients among the SM2 and SM3 SESCC patients (p = 0.018). The present results suggested that LVI was an independent prognostic factor in patients with SM2 and SM3 lymph node-negative SESCC; however their prognosis was not worse than that of patients with lymph node-positive SM2 and SM3 SESCC, for whom adjuvant therapy is indicated as a standard treatment.

A Sequence Resource of Autosomes and Additional Chromosomes in the Peach Pathotype of Alternaria alternata

Alternaria alternata is a generally saprophytic fungus. Its genome consists of 10 autosomes, while some strains have one or two additional chromosomes, called a conditionally dispensable chromosome (CDC). A CDC is not required for reproduction but confers host-specific pathogenicity. We sequenced the genome of the peach pathotype of A. alternata using Nanopore and assembled it into 20 sequences. The 10 largest sequences corresponded to 10 gapless sequences of A. solani autosomes, and 1 sequence was a mitochondrial genome. Nine other sequences may be derived from CDCs because of lack of similarity with autosomes of other Alternaria spp. The sequence information could provide novel insights into genomes of Alternaria spp. and on the biosynthesis of a novel host-specific toxin in the peach pathotype of A. alternata.

P1627Increased pericardial fibrosis and cardiac dysfunction in smooth muscle cell-specific SOCS3 deficient mice

Background

Suppressor of cytokine signaling-3 (SOCS3) is an intrinsic negative-feedback regulator of signal transducer and activator of transcription-3 (STAT3) signaling pathway. We have previously shown that myocardial SOCS3 plays an important role in cardiac hypertrophy and survival; however, the role of SOCS3 in smooth muscle cells in cardiovascular pathophysiology remains elusive. In this study, we determined whether STAT3 and SOCS3 in smooth muscle cells would play a role in cardiovascular pathophysiology.

Methods and results

To target inactivation of the SOCS3 gene to smooth muscle cells, SOCS3-flox mice were bred with transgenic mice expressing Cre recombinase under control of the mouse SM22-α promoter (sm-SOCS3-KO mice). Left ventricular weight to body weight ratio was significantly increased in sm-SOCS3-KO mice compared with wild-type mice at 52 weeks of age (p<0.05). Echocardiographic analyses of sm-SOCS3-KOmice showed significantly decreased cardiac function compared with wild-typefrom 52 weeks of age (p<0.05). Interestingly, Sirius-red staining revealed that thickness of pericardium in sm-SOCS3-KOmice was markedly greater compared with wild-typemice at 52 weeks of age (p<0.05). Cardiac interstitial fibrosis in sm-SOCS3-KOmice was also greater compared with wild-typemice (p<0.05). Western blot analyses showed that phosphorylated STAT3 was significantly increased in sm-SOCS3-KOhearts compared with wild-typemice at 52 weeks of age (p<0.05), whereas no significant differences were observed at 7 weeks of age. Immunostaining revealed that phosphorylated STAT3 positive cells were in thickened pericardial area in sm-SOCS3-KOhearts. Some infiltrated inflammatory cells were also found in thickened pericardial area in sm-SOCS3-KOmice hearts.

Conclusion

These results suggest that STAT3 and its negative-feedback regulator SOCS3 in smooth muscle cells play an important role in the pathogenesis of pericardial fibrosis and cardiac dysfunction.

P3534Optimal dosing of initial bolus of intravenous furosemide in acute heart failure: insights from REALITY-AHF

Background

Although intravenous diuretics are a cornerstone in the treatment of patients with acute heart failure (AHF), optimal dosing of initial bolus of IV diuretics has not been well elucidated.

Methods

The initial IV bolus dose of furosemide and its association with outcomes were analyzed in 1290 AHF patients (median age, 81 years, 55% were male) derived from REALITY-AHF (Registry Focused on Very Early Presentation and Treatment in Emergency Department of Acute Heart Failure). The patients were divided into 3 groups; lower dose (lower than recommended dose, n=371), standard dose (same as recommended dose, n=807), and higher dose (higher than recommended dose, n=112) groups according to the recommended initial IV bolus furosemide dose derived from the maintenance loop diuretics dose (for those without taking oral loop diuretics or taking ≤40mg/day oral furosemide-equivalent loop diuretics, 20mg IV bolus furosemide; those on >40mg/day oral furosemide-equivalent loop diuretics, IV bolus furosemide at the same dose as oral loop diuretic dose). Outcomes were length of hospital stay, diuretic response (urine output achieved within 48 hours of admission per 40 mg furosemide-equivalent diuretics dose), and 60-day all-cause mortality.

Results

Median amount of first IV bolus furosemide dose were 10, 20, and 40 mg for lower, standard, and higher dose groups, respectively. After adjustment for other covariates, length of hospital stay was significantly longer by 2.6 days (p=0.018) in the lower dose group compared to the standard dose group, and there was no difference between the standard and high dose groups (p=0.221). Diuretic response within 48 hours of admission was significantly better in the lower dose group (beta coefficient: 244 mL, p=0.025) and significantly worse in the higher dose group (beta coefficient: - 1098 mL, p<0.001) compared to the standard dose group after adjustment for covariates. During 60 days of admission, 91 deaths were observed, and 60-day mortality was significantly higher in the higher dose group (HR: 2.80, 95% CI: 1.49–5.26, p=0.001), but not in the lower dose group (HR: 1.18, 95% CI: 0.67–2.08, p=0.571) compared to the standard dose group after adjustment for other prognostic factors.

Conclusion

Treatment with the recommended initial bolus of IV furosemide is associated with a shorter hospital stay compared to lower dose regimen and better diuretic response and better 60-day survival compared to higher dose regimen in patients with AHF.

Acknowledgement/Funding

This study was funded by The Cardiovascular Research Fund, Tokyo, Japan.

428In-hospital coronary angiography is associated with increased evidence based medications and better survival in patients hospitalized with acute heart failure - results from REALITY-AHF

Background

Coronary artery disease is a major cause of heart failure (HF). Urgent coronary angiography (CAG) is recommended for patients with acute HF (AHF) complicated with acute coronary syndrome (ACS); however, clinical usefulness of in-hospital CAG in AHF patients without ACS remains unknown.

Purpose

To investigate the association between in-hospital CAG and all-cause mortality at 1-year after hospital discharge and effects of medications at discharge on this association.

Methods

From the REALITY-AHF study, 1344 patients hospitalized with AHF were enrolled in this study and followed up for 1-year after hospital discharge.

Results

In-hospital CAG was undergone in 511 patients (38%). CAG group had a significantly lower 1-year mortality compared with non-CAG group (unadjusted hazard ratio [HR]; 0.30, 95%-confidence interval [CI] 0.21–0.43, P<0.001, after adjustment for MAGGIC score; HR 0.45, 95%-CI 0.29–0.70, P<0.001, in propensity-score matched 296 pairs; HR 0.60, 95%-CI 0.37–0.98, P=0.04). At discharge, aspirin, statins and beta blockers were prescribed more in CAG group compared with non-CAG group (aspirin 46% versus 30%, P<0.001, statins 51% versus 35%, P<0.001, and beta blockers 76% versus 65%, P=0.007). The prescription of aspirin or statins at discharge was associated with a better 1-year survival in patients with multivessel disease (P<0.001), but not in patients without significant stenosis or single vessel disease (P=0.95) (Figure).

CAG results, medications and mortality

Conclusions

In patients hospitalized with AHF, in-hospital CAG was associated with increased evidence based medications at discharge and a better long-term survival. Aspirin and statins at discharge might improve outcomes in AHF patients with multivessel disease.

Acknowledgement/Funding

This study was funded by The Cardiovascular Research Fund, Tokyo, Japan.

P5374Genetic deletion of IL-22 increased cardiac rupture after myocardial infarction in mice

Background

Interleukin-22 (IL-22) is a member of the IL-10 cytokine family, which mainly targets epithelial cells and does not target immune cells. Recently, it has been reported that IL-22 play roles in tissue repair in the skin and the liver; however, role of IL-22 in the process of tissue repair after myocardial infarction (MI) is unknown. Here, we investigated the role of IL-22 in tissue repair process after MI.

Methods and results

First, we examined the expression of IL-22 and its receptor IL-22RA1 in the wild type (WT) mice by real-time PCR. The expression of IL-22 and IL-22RA1 in the hearts were significantly increased 3 days after MI (p<0.05). To clarify the role of IL-22 in the heart after MI, we produced MI model in the WT mice and IL-22 knockout (KO) mice. We found that the IL-22 KO mice had significantly higher mortality than the WT mice after MI (p<0.05). Approximately 80% of the IL-22 KO mice died with cardiac rupture after MI. The infarct size which was estimated by evans blue dye and triphenyltetrazolium chloride staining at 3 days after MI was comparable between the IL-22 KO mice and the WT mice. Next, we performed real time PCR and PCR array analysis for tissue fibrosis and repair genes. We found that alpha-smooth muscle actin (aSMA), NF-kB, TNF-a and MMP13 (also known as collagenase-3) were significantly increased in the infarct area of IL-22 KO mice compared to WT mice. Immunostaining showed that the myofibroblast marker aSMA positive cells in the border area after MI were markedly higher in the IL-22 KO mice compared with the WT mice (p<0.05). Approximately 70% of cardiac rupture after MI in the IL-22 KO mice were occurred in the infarct area adjacent to the border area. Furthermore, we found aSMA positive cells and MMP13 positive cells around the ruptured site of the heart.

Conclusion

Thus, IL-22 KO mice exhibit high mortality and increased cardiac rupture after MI. And expression of aSMA and MMP13 were highly expressed in the ruptured site after MI in the IL-22 KO mice. These results suggest that IL-22 may play an important role in the tissue repair process after MI.

124Impact of intimal tracking for recanalization of CTO lesions on long-term clinical outcomes

Background

For recanalization of coronary chronic total occlusion (CTO) lesions, subintimal guidewire tracking in both antegrade and retrograde approaches are commonly used.

Purpose

This study aimed to assess the impact of subintimal tracking on long-term clinical outcomes after recanalization of CTO lesions.

Methods

Between January 2009 and December 2016, 474 CTO lesions (434patients) were successfully recanalized in our center. After guidewire crossing in a CTO lesion, those lesions were divided into intimal tracking group (84.6%, n=401) and subintimal tracking group (15.4%, n=73) according to intravascular ultrasound (IVUS) findings. Long-term clinical outcomes including death, target lesion revascularization (TLR), target vessel revascularization (TVR) were compared between the two groups. In addition, the rate of re-occlusion after successful revascularization was also evaluated.

Results

The median follow-up period was 4.7 years (interquartile range, 2.8–6.1). There was no significant difference of the rate of cardiac death between the two groups (intimal tracking vs. subintimal tracking: 7.0% vs. 4.1%; hazard ratio, 0.61; 95% confidence interval [CI], 0.19 to 2.00; p=0.41), TLR (14.3% vs. 16.2%; hazard ratio, 1.34; 95% CI, 0.71 to 2.53; p=0.37), and TVR (17.5% vs. 20.3%; hazard ratio, 1.27; 95% CI, 0.72 to 2.23; p=0.42). However, the rate of re-occlusion was significantly higher in the subintimal tracking group than intimal tracking group at 3-years re-occlusion (4.2% vs. 14.5%; log-rank test, p=0.002, Figure). In the multivariate COX regression, subintimal guidewire tracking was an independent predictor of re-occlusion after CTO recanalization (HR: 5.40; 95% CI: 2.11–13.80; p<0.001).

Figure 1

Conclusions

Subintimal guidewire tracking for recanalization of coronary CTO was associated with significantly higher incidence of target lesion re-occlusion during long-term follow-up period.

Diffuse Pulmonary Meningotheliomatosis with Sarcomatous Transformation in a Shiba Dog

A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2-5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey-white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.

Prognostic significance of sarcopenia in patients undergoing esophagectomy for superficial esophageal squamous cell carcinoma

Nononcological prognostic factors in superficial esophageal squamous cell carcinoma (SESCC) patients remain unclear. The aim of this study is to evaluate the relationship between sarcopenia and surgical outcome in patients with SESCC who had undergone definitive surgery. A total of 194 SESCC patients who had undergone thoracic esophagectomy with three-field lymphadenectomy without neoadjuvant therapy at Tokai University Hospital between January 2006 and December 2015 were analyzed retrospectively. Manual tracing using CT imaging was used to measure the cross-sectional areas of the skeletal muscle mass. The cutoff values for the skeletal muscle index used to define sarcopenia were based on the results of a previous study. Twenty-eight patients (14.4%) had sarcopenia, while the remaining 166 patients (85.6%) did not. A multivariate analysis suggested that sarcopenia was an independent risk factor for postoperative pulmonary complications (OR = 3.232, P = 0.026). The overall survival rate and the disease-free survival rate were both significantly worse in the sarcopenia group than in the nonsarcopenia group (P < 0.001). In a multivariate analysis, sarcopenia was an independent prognostic factor affecting overall survival (HR = 7.121, P < 0.001) and disease-free survival (HR = 6.000, P < 0.001). Patients with sarcopenia and lymph node metastasis (n = 18) had a worse outcome than the other patients (P < 0.001). This study suggests that the alleviation of sarcopenia through nutritional support and rehabilitation in SESCC patients scheduled to undergo surgery might help to prevent postoperative pulmonary complications and to improve the long-term outcome.

Usefulness of Silent MR Angiography for Intracranial Aneurysms Treated with a Flow-Diverter Device

BACKGROUND AND PURPOSE

The flow-diverter device has been established as a treatment procedure for large unruptured intracranial aneurysms. The purpose of this study was to compare the usefulness of Silent MR angiography and time-of-flight MRA to assess the parent artery and the embolization state of the aneurysm after a flow-diverter placement.

MATERIALS AND METHODS

Seventy-eight large, unruptured internal carotid aneurysms in 78 patients were the subjects of this study. After 6 months of treatment, they underwent follow-up digital subtraction angiography, Silent MRA, and TOF-MRA, performed simultaneously. All images were independently reviewed by 2 neurosurgeons and 1 radiologist and rated on a 4-point scale from 1 (not visible) to 4 (excellent) to evaluate the parent artery. The aneurysmal embolization status was assessed with 2 ratings: complete or incomplete occlusion.

RESULTS

The mean scores of Silent MRA and TOF-MRA regarding the parent artery were 3.18 ± 0.72 and 2.31 ± 0.86, respectively, showing a significantly better score with Silent MRA (P < .01). In the assessment of the embolization of aneurysms on Silent MRA and TOF-MRA compared with DSA, the percentages of agreement were 91.0% and 80.8%, respectively.

CONCLUSIONS

Silent MRA is superior for visualizing blood flow images inside flow-diverter devices compared with TOF-MRA. Furthermore, Silent MRA enables the assessment of aneurysmal embolization status. Silent MRA is useful for assessing the status of large and giant unruptured internal carotid aneurysms after flow-diverter placement.

A case with good response to belimumab for lupus nephritis complicated by IgG4-related disease

Immunoglobulin (Ig)G4-related disease (IgG4-RD) is an unusual complication of systemic lupus erythematosus (SLE). We report a case in which belimumab proved efficacious for not only SLE, but also IgG4-RD. A 58-year-old Japanese woman had suffered from photodermatosis and erythema on the limbs for 20 years. She presented in slight fever and fatigue since 2016. Laboratory data showed hypergammaglobulinemia, proteinuria and positive results for anti-nuclear antibody and anti-double-stranded DNA antibody. Furthermore, elevated levels of serum IgG4 were detected. Contrast-enhanced computed tomography disclosed multiple areas of poor enhancement in the kidneys. The patient was diagnosed with lupus nephritis and IgG4-RD from renal biopsy. Treatment was started with prednisolone at 40 mg/day and mycophenolate mofetil. Proteinuria and serological findings improved initially, but tapering the dose of glucocorticoid proved difficult. After treatment was started with belimumab, clinical symptoms and proteinuria resolved completely. The dose of glucocorticoid was successfully tapered and serum concentration of IgG4 fell further. This appears to represent the first report of a case in which both SLE and IgG4-RD were effectively treated using belimumab.

Changes in topographical relation between the ductus arteriosus and left subclavian artery in human embryos: a study using serial sagittal sections

BACKGROUND

At birth, the ductus arteriosus (DA) merges with the aortic arch in the slightly caudal side of the origin of the left subclavian artery (SCA). Since the SCAs (7th segmental arteries) were fixed on the level of the 7th cervical-first thoracic vertebral bodies, the confluence of DA should migrate caudally. We aimed to describe timing and sequence of the topographical change using serial sagittal sections of 36 human embryos and foetuses (CRL 8-64 mm; 5-10 weeks), Those made easy evaluation of the vertebral levels possible in a few section.

MATERIALS AND METHODS

The DA or 6th pharyngeal arch artery seemed to slide down in front of the sympathetic nerve trunk along 1.0-1.2 mm from the second cervical vertebral level at 5-6 weeks and, at 6 weeks (CRL 14-17 mm), the DA confluence with aorta reached the 7th cervical level. Because of the highly elongated common carotid artery, the sliding of DA confluence seemed to be much shorter than the cervical vertebrae growing from 1 mm to 2.4 mm.

RESULTS

At the final topographical change at 6-7 weeks, the DA confluence further descended to a site 1-vertebral length below the left SCA origin. From 6 to 9 weeks, a distance from the top of the aortic arch to the left SCA origin was almost stable: 0.3-0.5 mm at 6 weeks and 0.4-0.6 mm at 9 weeks.

CONCLUSIONS

The heart descent and the caudal extension of the trachea and bronchi, those occurred before the DA sliding, were likely to be a major driving force for the sliding.