Objective To reveal the exact mechanical principle of the respiration-driven variation of cardiac function by observing the effect of respiratory intrathoracic pressure change (RIPC) on the mechanical models using echocardiography.Methods Model 1 was designed to observe the influence of RIPC on systemic and pulmonary venous return systems (SVR and PVR) respectively.Model 2,as an equivalent mechanical model of septal swing,was used to study the influence of RIPC on the motion of the interventricular septum (IVS).Results Model 1 demonstrated that the simulated RIPC had totally different influences on the simulated SVR and PVR.It increased the volume of the simulated right ventricle when the internal pressure was kept constant (8.16 cm H2O),while it had the opposite effect on PVR.Model 2demonstrated that there was a corresponding relationship between RIPC and the position of the simulated IVS which might be called pressure-position relationship.Conclusions The different anatomical arrangement of the two venous return systems leads to a different effect of RIPC on right and left ventricles,and thus generates a pressure gradient across IVS that tends to shift IVS left-and right-wards with respiration.The swing of the IVS changes the short axis diameters of the ventricles,thus their fillings and then their functions reciprocally.

Objective To investigate the therapeutic effect of nasal endoscope surgery on chronic sinusitis and nasal polyps in geriatric patients.Methods A total of 132 geriatric patients with chronic sinusitis and nasalpolyps underwent nasal endoscope surgery in our hospital from Jun.2010 to Jun.2014,and the therapeutic effect was investigated.Results In the 132 cases,92 cases were cured (69.7％).Therapeutic effects were excellent in 33 cases (25.0％),and invalid in 7 cases (5.3％).The total effective rate was 94.7％.The total effective rate was 100.0％ in type Ⅰ,97.4％ in type Ⅱ and 84.8％ in type Ⅲ.The total effective rate was higher in type Ⅰ and Ⅱ than in type Ⅲ (x2=3.506 and 6.218,P=0.035 and 0.012).Local complications occurred in 10 cases (7.6％),including 1 case with nasolacrimal duct injury,2 cases with orbital hematoma,5 cases with nasal adhesion,1 case with surgical cavity hemorrhage and 1 case with sinus atresia.Conclusions The therapeutic effects of nasal endoscopesurgery on chronic sinusitis and nasalpolyps are good in geriatric patients,especially in treating chronic sinusitis and nasalpolyps of type Ⅰ and Ⅱ,and the postoperative complications are less,which is worth clinical application.

Objective To investigate the affecting factors of interventricular septum (IVS) swing by study of the mechanical model of the respiration-driven variation of cardiac function using echocardiography.Methods In present study,the equivalent mechanical model of septal swing in previous study was used.By changing the end-diastolic pressure difference between the simulated right and left ventricles and simulated intrapericardial pressure,the subsequent influences on IVS swing using echocardiography were observed.Results Under the rhythmic respiratory intrathoracic pressure change(RIPC)(0--4 mm Hg,1 mm Hg =0.133 kPa),the swing amplitude of simulated IVS increased with decrease of the simulated end-diastolic pressure difference between the simulated right and left ventricles (2.2-17.6 mm).With increasing of the simulated intrapericardial pressure,the simulated right ventricle and left ventricle collapsed in succession,the swing amplitude of simulated IVS also increased to a maximal amplitude of 22.4 mm.Conclusions The affecting factors of IVS swing including the magnitude of RIPC,the end-diastolic pressure difference between the two ventricles and the intrapericardial pressure.

Objective To explore the feasibility of laparoscopic-assisted pancreaticoduodenectomy.Methods The clinical data of 5 patients in our hospital from January to May 2010 were analyzed. 2 patients were pre-operatively diagnosed to have lower common bile duct adenocarcinoma, and 2 patients were preoperatively diagnosed to have adenocarcinoma of the descending duodenum, 1 patient was intra-oparatively diagnosed to have pancreatic head cancer. During the operation, laparoscopic exploration was performed, then gallbladder, distant bile duct, distant stomach, duodenum, part of jejunum and head of pancreas were disassociated, then the digestive tract was reconstructed under open abdomen surgery. Results All the operations of the 5 cases were successfully performed, with an average operation time ( 339 ± 54) min and an intra-operative blood loss of (538 ± 106)ml, and there was no intra-operative blood transfusion. The patients'bowel function recovered (4.0 ± 1.0 ) d postoperatively and were discharged ( 15.8 ± 4.7 ) d postoperatively.1 patient developed pancreatic fistula and was cured with conservative treatment. Conclusions Laparoscopicassisted pancreatoduodenectomy is minimally invasive with short operation time and fast postoperative recovery,which is worth of further clinical study.

Objective Laryngeal and upper esophageal foreign bodies are common diseases, we explored a new and simple method to remove these foreign bodies. Methods The clinical data of 177 patients with laryngeal and upper esophageal foreign bodies from June 2008 to January 2016 were analyzed retrospectively. We used two methods to treat these foreign bodies:130 foreign bodies were directly removed under video endoscopy;47 foreign bodies were removed with suspension laryngoscopy, and video endoscopy was used meanwhile. Result 177 laryngeal and upper esophageal foreign bodies were removed well, without severe complications like esophageal perforation or phyryngeal fistula. Conclusion Removing esophageal and laryngeal foreign bodies with video endoscopy is simple, safe and effective.

Objective To observe the peripheral arterial Doppler flow velocity curve changes and elucidate the blood flow characteristics by adding extra pressure on the limbs,and to provide evidence for better diagnosis of peripheral arterial diseases by ultrasound.Methods Color Doppler ultrasound instrument was used to record the brachial artery(BA),radial artery(RA),common femoral artery(CFA) and popliteal artery(POA) Doppler flow velocity curves both at rest and under different grades of distal and proximal limb pressuring in 40 randomly selected healthy adults.The peak systolic and early diastolic reverse flow velocity(PSV,PRV) and the resistance index (RI) were measured and analyzed.Results Three-phase waveform was seen at rest.Significant changes were noticed in PRV and RI under distal pressuring,while no significant difference was seen in PSV between groups.Conclusions Normal peripheral arteries show pulsed step-by-step blood flow pattern along with the cardiac cycles.Peripheral arterial Doppler flow curves changes regularly with limb grading pressuring.

Objective To explore the mechanism of intrathoracic pressure(ITP) influncing cardiac function and facilitate noninvasive determination of ventricular pressure theoretically.Methods With Valsalva and Mueller maneuver,two-dimension images of standard long axis views and the cross-sectional views were recorded in 20 volunteers,aged from 18 to 45 years,at the specific ITP levels(including-20 mmHg、-10 mmHg、0 mmHg、+ 10 mmHg and + 20 mmHg).The subjects were instructed to mantain for at least 10 s,and three successive measurements were recorded and averaged.The stroke volume(SV) and radius of curvature(R) were obtained from further off-line analysis.Results With the ITP maintaining at -20 mmHg,-10 mmHg,0 mmHg(end expiration),+ 10 mmHg and + 20 mmHg respectively,the corresponding radiuses of curvature were (2.35 ±0.24)cm,(2.25 ± 0.23)cm,(2.14 ± 0.21)cm,(2.02 ± 0.21) cm,(1.93 ± 0.19) cm,there were statistically significances between two groups (P =0.006,0.031,0.005 and ＜0.001,respectively].When the ITP were at 0 mmHg(end expiration),+ 10 mmHg and + 20 mmHg,the stroke volume were (71.54±8.81)ml,(73.20±9.52)ml and (78.81± 14.61)ml (P =0.674,0.135).When the intrathoracic pressure decreased from 0 mmHg to-20 mmHg,the stroke volume were (78.81±14.61)ml,(68.28 ±9.28)ml and (59.69±7.52)ml(P =0.029,0.037).Conclusions The ITP has different effects on the two ventricles,and subsequently generates a pressure gradient across the IVS which can alter its shape and position at end-diastole.With the IVS shifting,the preload and filling function of left ventricle gets changed acorrding to the Frank Starling principle.

Objective To observe the clinical effect of platelet-rich fibrin (PRF) on prevention of postoperative hemorrhage and facial traumatic swelling in patients with mandibular angle osteotomy.Methods Twenty-five patients with mandibular angle hypertrophy were included in this study from January 2014 to November 2015.Split face comparative study was carried out to use the left and right sides as the experimental side and the control side,respectively.The PRF in the experimental side was placed in the mandibular osteotomy,while the control side was placed in platelet-poor plasma (PPP).After operation,the drainage volume and facial swelling degree were measured.Results The drainage volume of the experimental group (PRF group) was (20.35 ±7.40) ml,the control group (PPP group) was (43.23±11.96) ml,and the difference was statistically significant (P＜0.05).There was no such case without swelling in postoperative third day.The facial swelling score on the experimental side was (1.19±0.40),the control side was (2.62±0.64),and two groups of postoperative facial swelling scores were significantly different (P＜0.05).Conclusions The PRF can reduce postoperative bleeding and facial swelling after mandibular angle osteotomy.

Objective:To reveal the diurnal variation characteristics of the exercise adaptability of cardiac function in healthy men of different ages by the analysis of echocardiographic parameter changes before and after exercise intervention using the left ventricular pressure-strain loop techniques.Methods:A prospective control design was used to collect 193 healthy male volunteers from October 2022 to July 2023 in Tangdu Hospital, 101 in the young group [(26±5) years old], and 92 in the middle-aged group [(50±4) years old]. The heart rate, blood pressure and routine echocardiographic parameters were collected at rest and after exercise stress (3-minute step test) at 7∶00 a.m.and 10∶00 p.m., respectively. The heart rate, blood pressure cardiac output, and echocardiographic parameters [anteroposterior diameter of left atrium (LAD), ratio of peak early diastolic flow velocity to late diastolic peak flow velocity of mitral valve (E/A), left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVEDS)] were then determined. The parameters of myocardial work including left ventricular longitudinal strain (GLS), global work index (GWI), global work efficiency (GWE), global constructive work (GCW) and global wasted work (GWW) were obtained by left ventricular pressure-strain loop technique. The differences of the parameters above between before and after step test, morning and night, young group and middle-aged group were compared.Results:The heart rate, blood pressure and cardiac output of young and middle-aged healthy men increased significantly in the morning and night step test (all P<0.05), GLS, GWI, GCW and GWW were significantly higher than those in resting state (all P<0.05), and GWE was significantly lower than that in resting state ( P<0.05). The change rates of heart rate, cardiac output, GLS, GWI and GCW in the early morning were significantly higher than those at night (all P<0.05), while the change rates of blood pressure and GWE in each group were significantly lower than those at night ( P<0.05). The change rates of heart rate, systolic blood pressure, GLS and GWI in the middle-aged group were significantly higher than those in the young group in the morning and night (all P<0.05), while the change rate of diastolic blood pressure at night was significantly higher than that in the young group ( P<0.05), but there was no significant difference in the morning ( P>0.05). Conclusions:The cardiac adaptability of healthy men has obvious circadian rhythm, characterized by being of low in the morning and high in the evening. Age mainly affects the cardiac adaptability in the morning. The response to low-intensity load stimulation increases with aging, indicating the decrease of morning cardiac adaptability.

Objective Aged facial contour presents changing facial skeleton and sagging soft tissue.We performed reshaping the facial skeleton simultaneouly during the rhytidectomy to achieve a youthful facial contour.Methods It was a retrospective observational study based on 26 elderly women (42-60 years) that complained of aged face and boosing of the orbital rim,prominent zygoma and mandibular angle.All of them had undergone reduction boosing,malar and mandible combined with rhytidectomy from January 2010 to December 2015.Results The facial skeleton was reshaped with face-lift successfully.No fatal bleeding,respiratory obstruction,cardiovascular accident,severe facial edema,permanent facial nerve injury and other major complications occurred.All of the patients recovered safely.Follow-up for 3-24 months showed that the facial contour and aging were improved,and the youthful face form was preserved.Conclusions The face contour correction combined with face-lift is an effective technique to restore the youthful for elderly patients.