OBJECTIVE: To investigate the effectiveness of digital three-dimensional (3D) assisted unilateral biportal endoscopy (UBE) in the treatment of highly isolated lumbar disc herniation (LDH) with translaminar approach. METHODS: The clinical data of 59 patients who met the selection criteria and underwent UBE treatment due to highly isolated LDH between January 2022 and December 2023 were retrospectively analyzed. Among them, 25 cases were treated with digital 3D assisted translaminar approach (observation group) and 34 cases were treated with interlaminar approach (control group). There was no significant difference in gender, age, disease duration, surgical segment, and preoperative visual analogue scale (VAS) score and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative blood loss, and lateral articular surface preservation rate were recorded and compared between the two groups. VAS score and ODI were used to evaluate the improvements of pain and function before operation and at 3 and 6 months after operation. The modified MacNab criteria was used to evaluate the effectiveness at last follow-up. RESULTS: One patient in the control group had dural tear, and the other patients had no nerve injury, infection, dural tear, or other related complications. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). Patients in both groups were followed up 6-13 months, with an average of 8.3 months. The lateral articular surface preservation rate in the observation group was significantly higher than that in the control group ( P<0.05). Three patients in the observation group and 2 patients in the control group had calf muscle venous thrombosis, which was cured after anticoagulant treatment with rivaroxaban and delayed exercise time. There was no recurrence or second operation during the follow-up period. The VAS score and ODI of the two groups at 3 and 6 months after operation significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two groups at each time point after operation ( P>0.05). At last follow-up, the effectiveness was evaluated according to the modified MacNab criteria, and there was no significant difference in the evaluation grade and excellent and good rate between the two groups ( P>0.05). CONCLUTION UBE via translaminar approach is safe and effective for the treatment of highly isolated LDH, which is beneficial to protect the facet joint, maintain spinal stability, and reduce soft tissue injury. With the assistance of digital 3D technique, preoperative planning can be performed accurately.
Humans ; Intervertebral Disc Displacement/diagnostic imaging* ; Lumbar Vertebrae/diagnostic imaging* ; Male ; Retrospective Studies ; Female ; Endoscopy/methods* ; Treatment Outcome ; Middle Aged ; Adult ; Imaging, Three-Dimensional ; Operative Time ; Pain Measurement

OBJECTIVE To investigate the effect of Banxia Xiexin decoction(BXD) on colitis associated cancer(CAC) mice and its related mechanism. METHODS Seventy-five C57BL/6 mice were randomly divided into normal group, model group, Banxia Xiexin decoction low-dose group, high-dose group and mesalazine group. Except for the normal group, the mice in the other groups were intraperitoneally injected with azoxymethane combined with oral dextran sodium sulfate to establish the CAC model. BXD and mesalazine were given respectively for intervention. The general conditions of all mice were observed and recorded, and the changes of body weight, disease activity index, colon length and tumor number were monitored. HE staining was utilized to observe the pathological changes of colon tissue. The expression levels of PCNA, NF-κB P65 and IκB-α were detected by immunohistochemistry. The mRNA levels of IL-17A, N-cadherin, E-cadherin and Bcl-2 were detected by qRT-PCR. Macrophage infiltration was measured using immunostaining analysis. Western blotting was applied to analyze the expression of NF-κB, E-cadherin and N-cadherin proteins in colon tissues of each group. RESULTS There was no significant tumor occurrence in the normal group, while the body weight of the model group mice was significantly reduced and the number of colon tumors increased. The colon length, number of tumors, and degree of inflammatory cell infiltration in the BXD group were significantly improved compared to the model group. Immunohistochemical results showed that the expression of PCNA, NF-κB P65 and IκB-α protein in colon tissue of model group was remarkably increased (P<0.01). Immunofluorescence results showed that the number of F4/80, CD80 and CD206 positive macrophages in the colon tissue of the model group increased (P<0.05 or P<0.01). The results of RT-PCR demonstrated that the levels of IL-17A, N-cadherin and Bcl-2 mRNA in the colon tissue of the model group were significantly increased (P<0.01), while the level of E-cadherin mRNA was fundamentally decreased (P<0.01). Western blotting results displayed that the expression levels of NF-κB and N-cadherin protein in colon tissue of model group were up-regulated (P<0.01), while E-cadherin was significantly down-regulated (P<0.01). Compared with the model group, the changes of the above indexes in the BXD and mesalazine groups were ameliorated, with statistical differences (P<0.05 or P<0.01), and the changes in the BXD high-dose group were more significant. CONCLUSION BXD exhibits strong anti-inflammatory and anti-tumor benefits in CAC mice, inhibiting macrophage activation in colon tissue and promoting M2 polarization, while reducing the expression of tumor associated proteins PCNA and Bcl-2, and block the progression of EMT related proteins (E-cadherin and N-cadherin). The mechanism may connect to suppressing NF-κB P65 and IκB-α activation to regulate the NF-κB signaling pathway.

OBJECTIVE To investigate the effect of Banxia Xiexin decoction(BXD) on colitis associated cancer(CAC) mice and its related mechanism. METHODS Seventy-five C57BL/6 mice were randomly divided into normal group, model group, Banxia Xiexin decoction low-dose group, high-dose group and mesalazine group. Except for the normal group, the mice in the other groups were intraperitoneally injected with azoxymethane combined with oral dextran sodium sulfate to establish the CAC model. BXD and mesalazine were given respectively for intervention. The general conditions of all mice were observed and recorded, and the changes of body weight, disease activity index, colon length and tumor number were monitored. HE staining was utilized to observe the pathological changes of colon tissue. The expression levels of PCNA, NF-κB P65 and IκB-α were detected by immunohistochemistry. The mRNA levels of IL-17A, N-cadherin, E-cadherin and Bcl-2 were detected by qRT-PCR. Macrophage infiltration was measured using immunostaining analysis. Western blotting was applied to analyze the expression of NF-κB, E-cadherin and N-cadherin proteins in colon tissues of each group. RESULTS There was no significant tumor occurrence in the normal group, while the body weight of the model group mice was significantly reduced and the number of colon tumors increased. The colon length, number of tumors, and degree of inflammatory cell infiltration in the BXD group were significantly improved compared to the model group. Immunohistochemical results showed that the expression of PCNA, NF-κB P65 and IκB-α protein in colon tissue of model group was remarkably increased (P<0.01). Immunofluorescence results showed that the number of F4/80, CD80 and CD206 positive macrophages in the colon tissue of the model group increased (P<0.05 or P<0.01). The results of RT-PCR demonstrated that the levels of IL-17A, N-cadherin and Bcl-2 mRNA in the colon tissue of the model group were significantly increased (P<0.01), while the level of E-cadherin mRNA was fundamentally decreased (P<0.01). Western blotting results displayed that the expression levels of NF-κB and N-cadherin protein in colon tissue of model group were up-regulated (P<0.01), while E-cadherin was significantly down-regulated (P<0.01). Compared with the model group, the changes of the above indexes in the BXD and mesalazine groups were ameliorated, with statistical differences (P<0.05 or P<0.01), and the changes in the BXD high-dose group were more significant. CONCLUSION BXD exhibits strong anti-inflammatory and anti-tumor benefits in CAC mice, inhibiting macrophage activation in colon tissue and promoting M2 polarization, while reducing the expression of tumor associated proteins PCNA and Bcl-2, and block the progression of EMT related proteins (E-cadherin and N-cadherin). The mechanism may connect to suppressing NF-κB P65 and IκB-α activation to regulate the NF-κB signaling pathway.

Objective:To analyse the differences of related genes between serum alpha-fetoprotein (AFP) positive gastric cancer and AFP negative gastric cancer, and the relationship between related genes and prognosis of serum AFP positive gastric cancer.Methods:A total of 1 144 gastric cancer patients undergoing surgery at the 940th Hospital , Joint Logistic Support Force, People's Liberation Army from Jan 2013 to Dec 2018 were retrospectively analyzed. Of them, 47 cases were of AFP positive gastric cancer, and 47 serum AFP negative case were obtained by proper matching method.Results:Forty-seven patients with serum AFP positive gastric cancer, accounting for 4.1% of all gastric cancer patients during the same period. The prognosis of serum AFP negative gastric cancer is better than that of serum AFP positive gastric cancer. The 1-, 3- and 5-year cumulative survival rates were 95.6% vs. 63.8%, 48.9% vs. 23.4% and 26.7% vs. 14.9%, respectively. There were statistical differences in the immunohistochemistry of AFP, HER2, VEGF, GPC3, SALL4, P53 and Ki67 between the two groups ( χ2=67.758, P<0.001; χ2=4.004, P=0.044; χ2=19.299, P<0.001; χ2=5.232, P=0.022; χ2=6.359, P=0.012; χ2=6.224, P=0.013; χ2=5.232, P=0.022). The more co-positive expressions of AFP, GPC3, VEGF and SALL4, the more likely they were to affect pTNM stage, vascular invasion and liver metastasis ( χ2=5.328, P=0.021; P=0.013; χ2=5.887, P=0.015; χ2=3.923, P=0.048). Univariate and multivariate survival analysis of serum AFP positive gastric cancer showed:AFP, GPC3, VEGF and SALL4 were risk factors for AFP positive gastric cancer ( HR=3.700, P=0.036; HR=4.237, P=0.003; HR=3.916, P=0.004; HR=3.412, P=0.001). Conclusions:Serum AFP positive gastric cancer is a rare and highly invasive special type of gastric cancer. AFP, GPC3, VEGF and SALL4 are overexpressed in serum AFP positive gastric cancer, which is correlated with tumor stage, vascular invasion and liver metastasis. The final diagnosis of serum AFP positive gastric cancer still needs immunohistochemical examination. Preoperative serum AFP level is an important basis for AFP positive gastric cancer screening and AFP immunohistochemical examination.

Objective:To develop a robotic digestive endoscope system (RDES) and to evaluate its feasibility, safety and control performance by experiments.Methods:The RDES was designed based on the master-slave control system, which consisted of 3 parts: the integrated endoscope, including a knob and button robotic control system integrated with a gastroscope; the robotic mechanical arm system, including the base and arm, as well as the endoscopic advance-retreat control device (force-feedback function was designed) and the endoscopic axial rotation control device; the control console, including a master manipulator and an image monitor. The operator sit far away from the endoscope and controlled the master manipulator to bend the end of the endoscope and to control advance, retract and rotation of the endoscope. The air supply, water supply, suction, figure fixing and motion scaling switching was realized by pressing buttons on the master manipulator. In the endoscopy experiments performed on live pigs, 5 physicians each were in the beginner and advanced groups. Each operator operated RDES and traditional endoscope (2 weeks interval) to perform porcine gastroscopy 6 times, comparing the examination time. In the experiment of endoscopic circle drawing on the inner wall of the simulated stomach model, each operator in the two groups operated RDES 1∶1 motion scaling, 5∶1 motion scaling and ordinary endoscope to complete endoscopic circle drawing 6 times, comparing the completion time, accuracy (i.e. trajectory deviation) and workload.Results:RDES was operated normally with good force feedback function. All porcine in vivo gastroscopies were successful, without mucosal injury, bleeding or perforation. In beginner and advanced groups, the examination time of both RDES and ordinary endoscopy tended to decrease as the number of operations increased, but the decrease in time was greater for operating RDES than for operating ordinary endoscope (beginner group P=0.033; advanced group P=0.023). In the beginner group, the operators operating RDES with 1∶1 motion scaling or 5∶1 motion scaling to complete endoscopic circle drawing had shorter completion time [1.68 (1.40, 2.17) min, 1.73 (1.47, 2.37) min VS 4.13 (2.27, 5.16) min, H=32.506, P<0.001], better trajectory deviation (0.50±0.11 mm, 0.46±0.11 mm VS 0.82±0.26 mm, F=38.999, P<0.001], and less workload [42.00 (30.00, 50.33) points, 43.33 (35.33, 54.00) points VS 52.67 (48.67, 63.33) points, H=20.056, P<0.001] than operating ordinary endoscope. In the advanced group, the operators operating RDES with 1∶1 or 5∶1 motion scaling to complete endoscopic circle drawing had longer completion time than operating ordinary endoscope [1.72 (1.37, 2.53) min, 1.57 (1.25, 2.58) min VS 1.15 (0.86, 1.58) min, H=13.233, P=0.001], but trajectory deviation [0.47 (0.13, 0.57) mm, 0.44 (0.39, 0.58) mm VS 0.52 (0.42, 0.59) mm, H=3.202, P=0.202] and workload (44.62±21.77 points, 41.24±12.57 points VS 44.71±17.92 points, F=0.369, P=0.693) were not different from those of the ordinary endoscope. Conclusion:The RDES enables remote control, greatly reducing the endoscopists' workload. Additionally, it gives full play to the cooperative motion function of the large and small endoscopic knobs, making the control more flexible. Finally, it increases motion scaling switching function to make the control of endoscope more flexible and more accurate. It is also easy for beginners to learn and master, and can shorten the training period. So it can provide the possibility of remote endoscopic control and fully automated robotic endoscope.

Objective:To evaluate the safety and efficacy of transtobturator urethral sling operation in the treatment of male stress urinary incontinence.Methods:A retrospective analysis was conducted on the clinical data of 13 male patients with stress urinary incontinence who underwent transvaginal sling procedure at Peking University People's Hospital from June 2011 to July 2024. The patients' average age was (71.6±5.4) years. Among them, 9 patients had undergone radical prostatectomy, and 4 had undergone transurethral resection of the prostate (TURP). Of the 13 patients, 7 had moderate urinary incontinence, and 6 had severe urinary incontinence. The median daily number of urine pads used by the 13 patients before surgery was 5 (3, 8), and the median score of the Incontinence Quality of Life Questionnaire (I-QOL) was 16 (12, 28). The median score of the Male Stress Urinary Incontinence Grading Scale (MSIGS) was 2 (2, 3). All the 13 patients underwent transvaginal sling procedure. The patients were placed in the lithotomy position, and the urethral bulb was dissected anatomically beneath the scrotum. The sling was guided by a needle and pulled out through the obturator foramen, and placed over the urethral bulb. The sling was tightened and the tension adjusted to fully suspend the urethra. A urinary catheter was left in place for 1-7 days after surgery. The patients' postoperative daily use of urine pads, scores of the I-QOL and MSIGS, and postoperative complications were followed up.Results:Postoperative follow-up ranged from 2 to 139 months, with a median follow-up time of 12 months. Of the 13 patients, 2 were cured, 9 had improved and 2 had no significant improvement. The number of diapers used per day by patients postoperatively was 1 (1, 4) pieces, the I-QOL score was 75 (46, 82), and the MSIGS score was 1 (0, 2), which were all significantly improved compared to preoperative values ( P<0.01). Among the 6 severe stress urinary incontinence patients who were followed up, the number of diapers used per day was significantly reduced compared to preoperative values[ 2(1, 5) vs. 8(7, 8) pieces], and the I-QOL score was significantly improved [ 60(35, 70) vs. 12(10, 16) ], while the MSIGS score was significantly lower [ 2(1, 3) vs. 3(2, 4) ]. Among the 7 moderate stress urinary incontinence patients, the number of diapers used per day was significantly reduced compared to preoperative values [1 (0, 1) vs. 4 (4, 5) pieces], and the I-QOL score was significantly improved [ 80(75, 82) vs. 21(18, 30) ], while the MSIGS score was significantly lower [ 0 (0, 1) vs. 2 (2, 3) ]. The symptoms of 1 patient were not significantly improved after the surgery, and were improved after Virtue sling suspension 3 years later. Conclusions:The use of transtobturator urethral sling operation for the treatment of moderate to severe male stress urinary incontinence has shown clear efficacy, with a low incidence of postoperative complications.

Objective:To evaluate the effect of continuous positive airway pressure (CPAP) ventilation during induction of anesthesia on perioperative atelectasis and oxygenation in elderly patients.Methods:Forty-six elderly patients of either sex, aged 65-80 yr, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, undergoing elective cerebrovascular intervention surgery under general anesthesia, were divided into 2 groups ( n=23 each) according to the random number table method: control group (group C) and CPAP ventilation group (group CPAP). During induction of anesthesia, CPAP was set at 5 cmH 2O during spontaneous breathing, and PEEP was set at 5 cmH 2O when spontaneous breathing disappeared, and the ventilation mode was changed to pressure-controlled ventilation (PCV) mode in group CPAP. CPAP was not set, and PEEP was set at 0 cmH 2O for PCV when spontaneous breathing disappeared in group C. During anesthesia maintenance, PCV-volume guaranteed mode was used in both groups, and PEEP was set at 5 cmH 2O. Whole lung CT scanning was performed immediately after radial artery catheterization (T 0), at 1 min after endotracheal intubation (T 1), and before tracheal extubation (T 2) at the end of operation to calculate the percentage of atelectasis area at 1 cm above the right diaphragm. At T 0, T 1, T 2 and 30 min after entering postanesthesia care unit (T 3), blood samples from the radial artery were taken to record PaO 2 and PaCO 2 and calculate the oxygenation index (OI). Results:Compared with the baseline at T 0, the percentage of atelectasis area was significantly increased at T 1 and T 2 in two groups ( P<0.05); PaO 2 was significantly increased at T 1 and T 2 and decreased to T 0 level at T 3, OI was decreased at T 1 and T 2 and increased to T 0 level at T 3 in two groups ( P<0.05). Compared with group C, the percentage of atelectasis area was significantly decreased and PaO 2 and OI were increased at T 1 and T 2 in group CPAP ( P<0.05). There was no significant difference in PaCO 2 at each time point between the two groups ( P>0.05). Conclusions:CPAP ventilation during induction of anesthesia can reduce the development of perioperative atelectasis and improve the oxygenation in elderly patients.

Objective:To evaluate the effect of continuous positive airway pressure(CPAP) ventilation strategy during induction of general anesthesia on atelectasis after induction in obese patients.Methods:A total of 86 patients, aged 30-60 yr, with body mass index of 28-35 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱor Ⅲ, scheduled for elective cerebrovascular intervention under general anesthesia, were divided into 2 groups ( n=43 each) using a random number table method: CPAP group (group C) and routine group (group R). Group C received CPAP 5 cmH 2O-assisted ventilation after preoxygenation for spontaneous breathing and disappearance of spontaneous breathing. Chest CT scan and arterial blood gas analysis were performed after entering the operating room (T 1) and 5 min after endotracheal intubation (T 2) to calculate the percentage of atelectasis area and to record PaO 2. Dynamic lung compliance and plateau pressure were recorded at T 2. Mean minute ventilation under controlled breathing, P ETCO 2, and use of vasoactive drugs during induction were recorded. The occurrence of reflux and aspiration during mask ventilation was recorded. The development of pulmonary complications within 3 days after operation was recorded. Results:Compared with group R, the percentage of atelectasis area at T 2 was significantly decreased, PaO 2, dynamic lung compliance and plateau pressure were increased ( P<0.05), and no significant change was found in mean minute ventilation, P ETCO 2, requirement for vasoactive drugs and incidence of pulmonary complications in group C ( P>0.05). No reflux or aspiration was observed during mask ventilation. Conclusions:CPAP (5 cmH 2O) strategy during anesthesia induction can reduce the degree of atelectasis after induction in obese patients.

OBJECTIVE: To analyze the early effectiveness of unilateral biportal endoscopy (UBE) laminectomy in the treatment of two-level lumbar spinal stenosis (LSS). METHODS: The clinical data of 98 patients with two-level LSS treated with UBE between September 2020 and December 2021 were retrospectively analyzed. There were 53 males and 45 females with an average age of 59.9 years (range, 32-79 years). Among them, there were 56 cases of mixed spinal stenosis, 23 cases of central spinal canal stenosis, and 19 cases of nerve root canal stenosis. The duration of symptoms was 1.5- 10 years, with an average of 5.4 years. The operative segments were L _{2, 3} and L _{3, 4} in 2 cases, L _{3, 4} and L _{4, 5} in 29 cases, L _{4, 5} and L _5, S ₁ in 67 cases. All patients had different degrees of low back pain, among of which 76 cases were with unilateral lower extremity symptoms and 22 cases were with bilateral lower extremity symptoms. There were 29 cases of bilateral decompression in both segments, 63 cases of unilateral decompression in both segments, and 6 cases of unilateral decompression and bilateral decompression of each segment. The operation time, intraoperative blood loss, total incision length, hospitalization stay, ambulation time, and related complications were recorded. Visual analogue scale (VAS) score was used to assess the low back and leg pain before operation and at 3 days, 3 months after operation, and at last follow-up. The Oswestry disability index (ODI) was used to evaluate the functional recovery of lumbar spine before operation and at 3 months and last follow-up after operation. Modified MacNab criteria was used to evaluate clinical outcomes at last follow-up. Imaging examinations were performed before and after operation to measure the preservation rate of articular process, modified Pfirrmann scale, disc height (DH), lumbar lordosis angle (LLA), and cross-sectional area of the canal (CAC), and the CAC improvement rate was calculated. RESULTS: All patients underwent surgery successfully. The operation time was (106.7±25.1) minutes, the intraoperative blood loss was (67.7±14.2) mL, and the total incision length was (3.2±0.4) cm. The hospitalization stay was 8 (7, 9) days, and the ambulation time was 3 (3, 4) days. All the wounds healed by first intention. Dural tear occurred in 1 case during operation, and mild headache occurred in 1 case after operation. All patients were followed up 13-28 months with an average of 19.3 months, and there was no recurrence or reoperation during the follow-up. At last follow-up, the preservation rate of articular process was 84.7%±7.3%. The modified Pfirrmann scale and DH were significantly different from those before operation ( P<0.05), while the LLA was not significantly different from that before operation ( P=0.050). The CAC significantly improved ( P<0.05), and the CAC improvement rate was 108.1%±17.8%. The VAS scores of low back pain and leg pain and ODI at each time point after operation significantly improved when compared with those before operation, and the differences between each time points were significant ( P<0.05). According to the modified MacNab criteria, 63 cases were excellent, 25 cases were good, and 10 cases were fair, with an excellent and good rate of 89.8%. CONCLUSION UBE laminectomy is a safe and effective technique with little trauma and fast recovery for two-level LSS and the early effectiveness is satisfactory.
Male ; Female ; Humans ; Middle Aged ; Laminectomy ; Spinal Stenosis/surgery* ; Constriction, Pathologic/surgery* ; Low Back Pain ; Retrospective Studies ; Blood Loss, Surgical ; Endoscopy ; Lumbar Vertebrae/surgery* ; Spinal Fusion/methods* ; Decompression, Surgical ; Surgical Wound/surgery* ; Treatment Outcome

Objective:Evaluate the image quality of dual-layer spectral detector CT pulmonary angiography with low-dose contrast agents, and explore the influence of pulmonary artery diameter on the image quality.Methods:A total of 91 spectral CT pulmonary angiography from March 2022 to August 2022 were retrospectively analyzed. The cases were divided into Group 1 ( n=34, main pulmonary artery diameter ≥ 30 mm) and Group 2 ( n=57, main pulmonary artery diameter<30 mm). The dosage of contrast agent was 30 ml. The CT attenuation values(CT values), standard deviation(SD), signal-to-noise ratio(SNR), and contrast-to-noise ratio(CNR) values of pulmonary artery from the main trunk to the subsegmental pulmonary artery between two groups were compared. The CT dose index volume(CTDI vol) and dose-length production (DLP) were recorded. Two readers evaluated the image quality using three-point method. The inter-reader agreement was performed by Kappa test. Results:The CT values of the pulmonary trunk and left pulmonary artery between two groups was not significantly different ( P>0.05). The CT values of the left upper lobe artery, segmental artery, and subsegmental artery in Group 1 were lower than those in Group 2 ( t=-2.13, -2.17, Z=-2.33, P<0.05). The SD values of pulmonary trunk and segmental artery in Group 1 were higher than those in Group 2 ( t=2.27, Z=-2.23, P<0.05). The SD values of left pulmonary artery, left upper lobe artery, and subsegmental artery between two groups were not significantly different ( P>0.05). The SNR and CNR values of main pulmonary trunk, left pulmonary artery, left superior lobar artery, and segmental artery in Group 2 were higher than those in Group 1 ( Z=-2.45, -2.57, -2.09, -3.58, P<0.05; Z =-2.33, -2.42, -2.07, -3.45, P<0.05), while these values of the subsegmental artery between two groups were not significantly different ( P>0.05). The two readers had good consistency in evaluating image quality (Kappa value>0.75, P<0.05). Conclusions:Spectral CT pulmonary angiography with 30 ml contrast agent would generate good quality images. However, the distal pulmonary artery would be poorly revealed when the diameter of main pulmonary artery more than 30 mm, especially in patients with suspected pulmonary hypertension.