Endotoxins are common exogenous pyrogens. Excessive endotoxins in medical devices and injections can lead to serious consequences such as sepsis, septic shock, and even death. Therefore, endotoxin detection plays a crucial role in medical, pharmaceutical, and food sectors. The wide application of Limulus amebocyte lysate (LAL) has led to a sharp decline in the number of horseshoe crabs. Moreover, the LAL assay has limitations such as interbatch variations and difficulty in quantification. The recombinant factor C (rFC) assay is stable between batches, highly sensitive, and capable of quantitation, and thus it can be used as an alternative for the LAL assay. However, the high cost and complex procedures involved in producing recombinant factor C have limited the widespread application of this method. In order to simplify the preparation and reduce the production cost of recombinant factor C, this study focuses on the production of recombinant factor C based on the baculovirus expression system. Multiple measures such as a high-yield and anti-apoptotic vector qBac-IIIG, the optimal signal peptide, and the optimized codon were used to reach the goal of endotoxin detection with cell supernatant. This method simplifies the steps of protein purification. The sensitivity of the supernatant reached 0.05 EU/mL in a 1-L fermentation system, and 500 000 detecting reactions can be supported per liter of fermentation broth. This study increases the yield and activity of recombinant factor C, simplifies the procedures of protein purification, and reduces the cost, laying a foundation for the promotion and application of recombinant factor C in endotoxin detection.
Animals ; Recombinant Proteins/genetics* ; Horseshoe Crabs/chemistry* ; Baculoviridae/metabolism* ; Endotoxins/analysis* ; Protein C/biosynthesis* ; Genetic Vectors/genetics* ; Arthropod Proteins/genetics* ; Enzyme Precursors ; Serine Endopeptidases

Objective     To evaluate the early clinical outcomes of the Renatus® balloon-expandable valve in the treatment of severe aortic stenosis. Methods    From November 2021 to April 2022, a total of 38 patients who received Renatus® balloon-expandable valve for severe aortic stenosis in Guangdong Provincial People's Hospital were included. There were 22 males and 16 females, with an average age of 73.7±5.3 years. Mean aortic gradient and peak aortic jet velocity at baseline, post-procedure, and follow-up were compared. Clinical outcomes including all-cause mortality, perivalvular leakage, serious adverse cardiovascular events and the occurrence of permanent pacemaker implantation were assessed. Results    All patients completed the procedure successfully without conversion to thoracotomy or perioperative death. The post-implant mean aortic pressure gradient was decreased from 41.5 (27.8, 58.8) mm Hg to 6.0 (3.0, 8.0) mm Hg, and the peak aortic jet velocity was also decreased from 4.1±0.9 m/s to 1.7±0.4 m/s (P<0.001). Pacemakers were required in 2 (5.3%) patients. The median follow-up time was 27.5 (23.0, 87.5) d, with a follow-up rate of 100.0%. The mean aortic gradient was 8.0 (7.0, 10.8) mm Hg and peak aortic jet velocity was 2.0±0.3 m/s, showing significant improvement compared with those in the preoperative period (P<0.001). No severe aortic regurgitation or paravalvular leak was observed. There was no serious cardiovascular adverse event or reoperative event during the study period. Conclusion    Transcatheter aortic valve replacement with the domestic Renatus® balloon-expandable valve system is a safe and effective procedure for selected patients with severe aortic stenosis who are at high risk or not candidates for surgical aortic valve replacement.

Objective     To analyze the clinical efficacy and survival outcome of totally thoracoscopic redo mitral valve replacement and evaluate its efficiency and safety. Methods     The clinical data of patients with totally thoracoscopic redo mitral valve replacement in Guangdong Provincial People’s Hospital between 2013 and 2019 were retrospectively analyzed. Survival analysis was performed using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to determine the risk factors for postoperative death. Results     There were 48 patients including 29 females and 19 males with a median age of 53 (44, 66) years. All the procedures were performed successfully with no conversion to median sternotomy. A total of 15, 10 and 23 patients received surgeries under non-beating heart, beating heart and ventricular fibrillation, respectively. The in-hospital mortality rate was 6.25% (3/48), and the incidence of early postoperative complications was 18.75% (9/48). Thirty-five (72.92%) patients had their tracheal intubation removed within 24 hours after the operation. The 1- and 6-year survival rates were 89.50% (95%CI 81.30%-98.70%) and 82.90%(95%CI 71.50%-96.20%), respectively. Age>65 years was an independent risk factor for postoperative death (P=0.04). Conclusion     Totally thoracoscopic redo mitral valve replacement is safe and reliable, with advantages of rapid recovery, reducing blood transfusion rate, reducing postoperative complications and acceptable long-term survival rate. It is worthy of being widely popularized in the clinic.

Objective    To determine the clinical efficacy of transcatheter aortic valve replacement (TAVR) for severe aortic regurgitation (AR) combined with severe mitral regurgitation (MR). Methods    The clinical data of 13 patients who underwent TAVR due to severe AR combined with severe MR from March 2018 to September 2021 in our hospital were retrospectively analyzed, including 10 males and 3 females with a mean age of 72.54±2.35 years. The echocardiographic findings of all patients were compared preoperatively and postoperatively. Results    Surgeries were performed successfully in all patients without intraoperative death or conversion to sternotomy. The operation time was 118.15±11.42 min, intraoperative blood loss was 100.00 (75.00, 250.00) mL, and the length of hospital stay after surgery was 9.00 (4.50, 11.00) d. The mean follow-up duration was 10.00 (6.50, 38.50) months, during which there were 2 patients with mild to moderate AR, 6 with mild AR, and 5 with no AR; meanwhile, severe MR decreased significantly (P=0.001) even without active intervention, including 4 mild to moderate MR and 9 mild MR patients. Compared to preoperative indexes, the left atrial diameter [46.00 (41.00, 52.50) mm vs. 35.00 (34.00, 41.00) mm, P<0.001], left ventricular end-systolic diameter [45.00 (36.00, 56.00) mm vs. 35.00 (28.00, 39.00) mm, P=0.002] and left ventricular end-diastolic diameter (62.62±2.40 mm vs. 51.08±2.49 mm, P<0.001) showed a decreasing trend during the follow-up. Conclusion    In selected patients with severe AR combined with severe MR, TAVR alone improves AR and combined MR at the same time.

Objective     To summarize the early results and clinical experience of using the J-Valve for transcatheter valve-in-valve implantation in patients with degenerated bioprosthesis at different anatomic positions. Methods     A retrospective analysis was conducted to evaluate the short-term outcomes of 39 consecutive patients who underwent transcatheter valve-in-valve implantation using the J-Valve System in the Department of Cardiac Surgery of Guangdong Provincial People’s Hospital from April 2020 to August 2021 due to bioprosthetic degeneration at different  anatomic positions. Among them, 35 patients underwent transcatheter mitral valve-in-valve (TMViV) implantation, 1 transcatheter aortic valve-in-valve (TAViV) implantation, 1 transcatheter tricuspid valve-in-valve (TTViV) implantation, 1 TMViV implantation with simultaneous TAViV implantation, and another one TMViV implantation with simultaneous transcatheter aortic valve replacement (TAVR) and perivalvular leakage (PVL) closure. Results     Among the 35 patients who underwent isolated TMViV implantation, 17 were male and 18 were female with a mean age of 72.6±10.8 years. Mean duration between two operations was 10.5±2.7 years. The mean Society of Thoracic Surgeons and EuroSCORE Ⅱ scores were 12.95%±9.61% and 13.91%±8.94%, respectively. The device success rate was 97.1% and no death occured during the operation. One patient was transferred to thoracotomy due to device displacement, 1 was re-opened for uncontrolled bleeding, and 1 presented left ventricular outflow tract obstruction. One patient underwent craniotomy due to intracranial hemorrhage within 30 days after surgery, and no other complications occurred including death, stroke, permanent pacemaker implantation, cardiac tamponade, or re-hospitalization. The mean follow-up time was 6.0±4.4 months, the mean mitral valve gradient was significantly improved (10.4±2.0 mm Hg vs. 5.5±1.2 mm Hg, P<0.05), and the New York Heart Association class≤Ⅱ in all the patients at the last follow-up. Among the other 4 patients who did not undergo isolated TMViV implantation, the transapical TAViV implantation and the trans-right atrium TTViV implantation were successful without intra- or post-operative complications. The patient who underwent TMViV and TAViV implantation simultaneously via transapical approach died of severe pulmonary hemorrhage and multiple organ failure 16 days after surgery. The other patient who underwent transapical TMViV combined with TAVR and PVL closure died of septic shock 10 days after the surgery. Conclusion     Transcatheter valve-in-valve implantation using the J-Valve system is shown to be a safe and effective procedure to treat mitral, aortic and tricuspid bioprosthetic valve dysfunction in high-risk patients, providing a new alternative to surgical surgery for degenerated bioprosthesis at different anatomic positions. However, simultaneous different valves intervention should be very cautious.

Objective     To explore the evolving strategies and compare perioperative and long-term outcomes of tricuspid valve replacement (TVR) in recent 20 years in our hospital. Methods    Between 1998 and 2018, the clinical data of 608 patients who underwent TVR at the Department of Cardiac Surgery, Guangdong Provincial People’s Hospital were retrospectively analyzed. There were 201 males and 407 females, with a median age of 47.0 (36.0, 57.0) years. Patients were divided into a biological tricuspid valve (BTV, n=427) group and a mechanical tricuspid valve (MTV, n=181) group. Propensity score matching was used to balance the baseline difference. Surgical strategy evolving, postoperative and long-term outcomes were analyzed between the two groups. Results    Since 2008, the usage ratio of biological valves was significantly higher than that of mechanical valves. Seventy-nine (13.0%) patients died in hospital after TVR. Before propensity score matching, the postoperative mortality of the BTV group was higher than that of the MTV group (15.2% vs. 7.7%, P=0.012), and there was no statistical difference between the two groups after matching (10.4% vs. 7.2%, P=0.372). The duration of postoperative ventilator support in the BTV group was longer than that in the MTV group [22.0 (15.0, 37.0) h vs. 19.0 (11.0, 27.0) h, P=0.003], and the incidence of postoperative dialysis and re-thoracotomy exploring for bleeding was higher in the BTV group (8.9 % vs. 2.8%, 9.4% vs. 6.6%, respectively). However, there was no statistical difference in mortality after matching. The median follow-up time of discharged patients was 101.0 (65.0, 147.0) months, ranged from 1 to 265 months, and the follow-up rate was 82.2%. During the follow-up period, there were 101 deaths (19.1%) of whom 68 were from the BTV group and 33 from the MTV group. The survival rates at 1 year, 5 years, 10 years, 15 years and 20 years of all patients were 85.0% (95%CI 82.2-87.9), 78.9% (95%CI 75.7-82.4), 71.1% (95%CI 67.3-75.3), 59.7% (95%CI 54.2-65.6) and 51.7% (95%CI 43.3-60.7), and there was no statistical difference between the two groups after matching (P=0.46). The median time of tricuspid valve failure was 84.0 (54.0-111.0) months. Conclusion    TVR is associated with high perioperative risks. There is no statistical difference in early mortality and long-term survival between biological and mechanical valve, while patients with mechanical valve has higher risk of re-operation for valve failure. Therefore, the type of prosthetic valve can be selected according to the patients' age, physical condition and the doctors’ experience.

Objective    To determine the clinical efficacy of transapical transcatheter mitral valve-in-valve treatment for patients with deteriorated mitral bioprosthesis after aortic-mitral double valve replacement. Methods    The clinical data of 9 patients who underwent transapical transcatheter mitral valve-in-valve implantation after aortic-mitral double valve replacement due to mitral bioprosthesis deterioration from May 2020 to January 2021 in our hospital were retrospectively analyzed, including 4 males and 5 females with a mean age of 72.44±7.57 years. Results    Surgeries were performed successfully in all patients with no conversion to median sternotomy. The mean procedural time was 101.33±48.49 min, the mechanical ventilation time was 23.11±26.54 h, the ICU stay was 1.89±1.05 d and the postoperative hospital stay was 6.11±2.02 d. Residual mild mitral regurgitation was only observed in 1 patient. Only 1 patient needed postoperative blood transfusion. No major complications were observed in all patients. There was no death in postoperative 90 days. Conclusion    For patients with deteriorated mitral bioprosthesis after aortic-mitral double valve replacement, transapical transcatheter mitral valve-in-valve implantation achieves good clinical results and effectively  improves the hemodynamics without increasing the risk of postoperative left ventricular outflow tract obstruction. The surgery is feasible and effective.

Objective    To explore the therapeutic effects of different surgical strategies on women with mechanical valve dysfunction during pregnancy. Methods    A total of 11 patients with mechanical valve dysfunction during pregnancy who underwent surgeries in our hospital from 2007 to 2017 were retrospectively included. The average age was 27.5±3.7 years. The prognosis of patients was analyzed according to the gestational weeks, cardiac function and the severity of mechanical valve dysfunction. Results    No death occurred. Three of them suffered subtotal hysterectomy during the surgery because of uncontrolled bleeding, and the others recovered without complications. Among the 5 patients with pregnancies <28 weeks, 1 patient was found intrauterine death before hospital admission, 2 suffered fetal loss 5 days after the cardiac surgery, and the other 2 patients continued their gestations until deliveries. Among the other 6 patients with pregnancies >28 weeks, 1 fetus died because of intracranial hemorrhage, and the other 5 survived without embryopathy or foetopathy. Conclusion    Gestation week, cardiac function and severity of mechanical valve dysfunction may be taken into account when making a treatment regimen for women with dysfunctional valve prostheses during pregnancy.

Objective:To summarize the experience and early outcomes of transapical mitral valve-in-valve procedure with J-Valve in patients with bioprostheses degeneration.Methods:The clinical data of 29 patients who underwent mitral transcatheter valve-in-valve implantation with J-Valve from April 2020 to March 2021 were retrospectively analyzed. There were male 16 and female 13 patients with average age (72.0±11.6) years. Patients underwent previous mitral valve replacement with bioprostheses of Hancock Ⅱ in 17, Edwards SAV in 7, Edwards Perimount in 3, Balmedic in 1, Mosaic in 1. The size of mitral bioprostheses included 25 # for 8 patients, 27 # for 17 patients, and 29 # for other 4 patients. The operations were performed in the hybrid operation room. Under X-ray fluoroscopy and TEE monitoring, the retro-preseted J-valve was implanted into the mitral bioprosthetic valve via the intercostal space and apical puncture. Results:One patient was converted urgently to mediate sternotomy, and the transcatheter mitral valve was reset after opening left atrium on cardiopulmonary bypass due to the migration of transcatheter valve. twenty eight patients were successfully completed transcatheter mitral valve-in-valve procedure with technical success achieving in 96.6% . Among the 28 patients who successfully were completed valve-in-valve procedure, 1 died and 27 were discharged in well condition. The mean mitral transvalvular gradient was (7.6±2.2)mmHg(1 mmHg=0.133 kPa), no death or other major complications occurred during the follow-up.Conclusion:The application of J-Valve interventional valve in patients with bioprosthesis degeneration can achieve favourable early outcomes, even if the patient was replaced with a small bioprosthesis in the previous operation, the hemodynamic effect was still satisfactory.

Objective    To investigate the effectiveness and safety of totally endoscopic transmitral myectomy (TETM) for hypertrophic obstructive cardiomyopathy (HOCM), comparing with traditional sternotomy modified Morrow procedure (SMMP). Methods    Thirty-eight patients with HOCM who needed surgical intervention were selected from our hospital in 2019, including 14 males and 24 females, with an average age of 56 (44-68) years. According to the operation method, they were divided into a TETM group (n=18) and a SMMP group (n=20). Appropriate patients  were screened by propensity matching scores. Finally, the clinical data of two matched groups were compared and