Least Squares Support Vector Machine Kalman Filter for Physiological Tremor Suppression in Minimally Invasive Surgical Robot

This paper studies the physiological tremor filtering in minimally invasive surgical robot.The surgeon􀆳s physiological tremor of the hand can cause the vibration of the tip of the surgical instrument,which may reduce operative accuracy and limit the application of surgical robots.Aiming at the vibration caused by physiological tremor of hand,we propose a Least Squares Support Vector Machine Kalman Filter(LSSVMKF),which can filter the tremor by estimating and modeling the tremor signal by Kalman filter and then superimposing it reversely in the control signal.When estimating and modeling the tremor signal,the filter uses the Least Squares Support Vector Machine(LS⁃SVM)to build the regression model of the constant parameters(Process Noise Covariance and Measurement Noise Covariance)of the traditional Kalman filter,which can dynamically adjust these parameters during the operation and improve the accuracy of Kalman filter.The simulation results show that the LSSVMKF can effectively filter out the tremor signal,thereby improving the accuracy of surgery.

Minimally Invasive Surgical Technique in Double Aortic Arch with Distal Atretic Left-Side in Infant:From a Single-Surgeon Clinical Experience

Background:Double aortic arch(DAA)with distal left-sided aortic arch atresia(LAAA)can form complete vascular ring by ligamentum connection.We aimed to introduce an uncommon DAA-LAAA diagnosis and treatment by the minimally invasive surgical technique(MIST).Methods:We retrospectively reviewed 7 cases of DAA-LAAA that were treated from January 2017 to July 2021.All infant patients underwent surgical repair by minimally invasive surgical technique.Mean follow-up was 14.43 months(range,5–21 months).Results:There were seven patients with DAA-LAAA,including six males and one female.Median age was 19.29 months(range,9.0–29.0 months).Median weight was 11.30 kg(range,9.6–13.0 kg).Three patients were found severe tracheal compression by cardiac computed tomography angiography(cCTA).Six patients with isolated DAA-LAAA were performed operations through left subaxillary minithoracotomy,and one patient with ventricular septal defect(VSD)was performed operation concurrently under the cardiopulmonary bypass(CPB)through right subaxillary minithoracotomy.All patients had symptom improvement in the postoperative period and discharged successfully.Follow-up data showed good results in short-term.Conclusions:We introduce a new surgical pathway for DAA-LAAA treatment with good symptomatic relief in short-term.MIST is a safe,feasible and economical approach for infant patients.

Feasibility and safety of minimally invasive multivisceral resection for T4b rectal cancer:A 9-year review

BACKGROUND Colorectal cancer is the third most common cancer and the second highest cause of cancer-related mortality worldwide.About 5%-10%of patients are diagnosed with locally advanced rectal cancer(LARC)on presentation.For LARC invading into other structures(i.e.T4b),multivisceral resection(MVR)and/or pelvic ex-enteration(PE)remains the only potential curative surgical treatment.MVR and/or PE is a major and complex surgery with high post-operative morbidity.Minimally invasive surgery(MIS)has been shown to improve short-term post-operative outcomes in other gastrointestinal malignancies,but there is little evi-dence on its use in MVR,especially so for robotic MVR.This is a single-center retrospective cohort study from 1st January 2015 to 31st March 2023.Inclusion criteria were patients diagnosed with cT4b rectal cancer and underwent MVR,or stage 4 disease with resectable systemic metastases.Pa-tients who underwent curative MVR for locally recurrent rectal cancer,or me-tachronous rectal cancer were also included.Exclusion criteria were patients with systemic metastases with non-resectable disease.All patients planned for elective surgery were enrolled into the standard enhanced recovery after surgery pathway with standard peri-operative management for colorectal surgery.Complex sur-gery was defined based on technical difficulty of surgery(i.e.total PE,bladder-sparing prostatectomy,pelvic lymph node dissection or need for flap creation).Our primary outcomes were the margin status,and complication rates.Cate-gorical values were described as percentages and analysed by the chi-square test.Continuous variables were expressed as median(range)and analysed by Mann-Whitney U test.Cumulative overall survival(OS)and recurrence-free survival(RFS)were analysed using Kaplan-Meier estimates with life table analysis.Log-rank test was performed to determine statistical significance between cumulative estimates.Statistical significance was defined as P<0.05.Meier estimates with life table analysis.Log-rank test was performed to determine statistical significance between cumulative estimates.Statistical significance was defined as P<0.05.RESULTS A total of 46 patients were included in this study[open MVR(oMVR):12(26.1%),miMVR:36(73.9%)].Patients’American Society of Anesthesiologists score,body mass index and co-morbidities were comparable between oMVR and miMVR.There is an increasing trend towards robotic MVR from 2015 to 2023.MiMVR was associated with lower estimated blood loss(EBL)(median 450 vs 1200 mL,P=0.008),major morbidity(14.7%vs 50.0%,P=0.014),post-operative intra-abdominal collections(11.8%vs 50.0%,P=0.006),post-operative ileus(32.4%vs 66.7%,P=0.04)and surgical site infection(11.8%vs 50.0%,P=0.006)compared with oMVR.Length of stay was also shorter for miMVR compared with oMVR(median 10 vs 30 d,P=0.001).Oncological outcomes-R0 resection,recurrence,OS and RFS were comparable between miMVR and oMVR.There was no 30-d mortality.More patients underwent robotic compared with laparoscopic MVR for complex cases(robotic 57.1%vs laparoscopic 7.7%,P=0.004).The operating time was longer for robotic compared with laparoscopic MVR[robotic:602(400-900)min,laparoscopic:Median 455(275-675)min,P<0.001].Incidence of R0 resection was similar(laparoscopic:84.6%vs robotic:76.2%,P=0.555).Overall complication rates,major morbidity rates and 30-d readmission rates were similar between la-paroscopic and robotic MVR.Interestingly,3-year OS(robotic 83.1%vs 58.6%,P=0.008)and RFS(robotic 72.9%vs 34.3%,P=0.002)was superior for robotic compared with laparoscopic MVR.CONCLUSION MiMVR had lower post-operative complications compared to oMVR.Robotic MVR was also safe,with acceptable post-operative complication rates.Prospective studies should be conducted to compare short-term and long-term outcomes between robotic vs laparoscopic MVR.

Minimally invasive pelvic exenteration for primary or recurrent locally advanced rectal cancer:A glimpse into the future

Surgeons have grappled with the treatment of recurrent and T4b locally advanced rectal cancer(LARC)for many years.Their main objectives are to increase the overall survival and quality of life of the patients and to mitigate postoperative complications.Currently,pelvic exenteration(PE)with or without neoadjuvant treatment is a curative treatment when negative resection margins are achieved.The traditional open approach has been favored by many surgeons.However,the technological advancements in minimally invasive surgery have radically changed the surgical options.Recent studies have demonstrated promising results in postoperative complications and oncological outcomes after robotic or laparoscopic PE.A recent retrospective study entitled“Feasibility and safety of minimally invasive multivisceral resection for T4b rectal cancer:A 9-year review”was published in the World Journal of Gastrointestinal Surgery.As we read this article with great interest,we decided to delve into the latest data regarding the benefits and risks of minimally invasive PE for LARC.Currently,the small number of suitable patients,limited surgeon experience,and steep learning curve are hindering the establishment of minimally invasive PE.

In-Hospital Outcomes in Minimally Invasive Mitral Valve Surgery: First Results in a Brazilian Single Center

Introduction: Treatments for cardiovascular diseases have increasingly evolved with the tendency to offer minimally invasive or transcatheter procedures instead of conventional sternotomy surgery. In this context, we highlight minimally invasive mitral valve surgery (MIMVS), which has been shown to be an increasingly solid option with some superior results when compared to the conventional technique: better pain control, shorter hospital stays, shorter recovery time, shorter readmission rate in the first postoperative year, better aesthetic results, and lower overall cost. Aim: This study aims to evaluate the stages of MIMVS, by primary mitral valve consultation, in our service and compare these results with data from the literature. Methods: All electronic medical records of patients who underwent MIMVS for primary mitral valve injury in the Encore Hospital from January 2020 to February 2023 were analyzed. Tabulation and statistical analysis were performed using the Microsoft Excel® program. Quantitative variables were presented as means, standard deviations. Results: 46 patients were enrolled in our study (Age: 59.1 ± 12.4 years old;60.8% Female, BMI: 26 ± 4.4 Kg/m2, Low risk STS score: 82.6%). The observed 30-day mortality was 2.1%, plastic rate of 23.9%, blood transfusion rate of 41.3%, length of stay in an intensive care bed (ICB) of 3.3 ± 3.3 days and hospital stay of 6.4 ± 5.1 days. Conclusions: We noticed that the MIMVS results carried out in our service agree with data from national and international literature with approximately 1.3 days more hospitalization in ICB.

Carbon footprints in minimally invasive surgery:Good patient outcomes,but costly for the environment

Advancements in technology and surgical training programs have increased the adaptability of minimally invasive surgery(MIS).Gastrointestinal MIS is superior to its open counterparts regarding post-operative morbidity and mortality.MIS has become the first-line surgical intervention for some types of gastrointestinal surgery,such as laparoscopic cholecystectomy and appendicectomy.Carbon dioxide(CO_(2))is the main gas used for insufflation in MIS.CO_(2)contributes 9%-26%of the greenhouse effect,resulting in global warming.The rise in global CO_(2)concentration since 2000 is about 20 ppm per decade,up to 10 times faster than any sustained rise in CO_(2)during the past 800000 years.Since 1970,there has been a steady yet worrying increase in average global temperature by 1.7℃ per century.A recent systematic review of the carbon footprint in MIS showed a range of 6-814 kg of CO_(2)emission per surgery,with higher CO_(2)emission following robotic compared to laparoscopic surgery.However,with superior benefits of MIS over open surgery,this poses an ethical dilemma to surgeons.A recent survey in the United Kingdom of 130 surgeons showed that the majority(94%)were concerned with climate change but felt that the lack of leadership was a barrier to improving environmental sustainability.Given the deleterious environmental effects of MIS,this study aims to summarize the trends of MIS and its carbon footprint,awareness and attitudes towards this issue,and efforts and challenges to ensuring environmental sustainability.

Update on minimally invasive surgery and benign prostatic hyperplasia

Transurethral resection of the prostate(TURP)became the gold standard surgical treatment for benign prostatic obstruction without undergoing randomized controlled trials against the predecessor standard in open suprapubic prostatectomy.TURP has historically been associated with significant morbidity and this has fuelled the development of minimally invasive surgical treatment options.Improvements in perioperative morbidity for TURP has been creating an ever increasing standard that must be met by any new technologies that are to be compared to this gold standard.Over recent years,there has been the emergence of novel minimally invasive treatments such as the prostatic urethral lift(PUL;UroLift System),convective WAter Vapor Energy(WAVE;Rezum System),Aquablation(AQUABEAM System),Histotripsy(Vortx Rx System)and temporary implantable nitinol device(TIND).Intraprostatic injections(NX-1207,PRX-302,botulinum toxin A,ethanol)have mostly been used with limited efficacy,but may be suitable for selected patients.This review evaluates these novel minimally invasive surgical options with special reference to the literature published in the past 5 years.

Minimally invasive surgery for upper gastrointestinal cancer: Our experience and review of the literature

Minimally invasive surgery (MIS) for upper gastrointestinal (GI) cancer, characterized by minimal access, has been increasingly performed worldwide. It not only results in better cosmetic outcomes, but also reduces intraoperative blood loss and postoperative pain, leading to faster recovery; however, endoscopically enhanced anatomy and improved hemostasis via positive intracorporeal pressure generated by CO2 insufflation have not contributed to reduction in early postoperative complications or improvement in long-term outcomes. Since 1995, we have been actively using MIS for operable patients with resectable upper GI cancer and have developed stable and robust methodology in conducting totally laparoscopic gastrectomy for advanced gastric cancer and prone thoracoscopic esophagectomy for esophageal cancer using novel technology including da Vinci Surgical System (DVSS). We have recently demonstrated that use of DVSS might reduce postoperative local complications including pancreatic fistula after gastrectomy and recurrent laryngeal nerve palsy after esophagectomy. In this article, we present the current status and future perspectives on MIS for gastric and esophageal cancer based on our experience and a review of the literature.

Role of minimally invasive techniques in gastrointestinal surgery:Current status and future perspectives

In recent years,the incidence of gastrointestinal cancer has remained high.Currently,surgical resection is still the most effective method for treating gastrointestinal cancer.Traditionally,radical surgery depends on open surgery.However,traditional open surgery inflicts great trauma and is associated with a slow recovery.Minimally invasive surgery,which aims to reduce postoperative complications and accelerate postoperative recovery,has been rapidly developed in the last two decades;it is increasingly used in the field of gastrointestinal surgery and widely used in early-stage gastrointestinal cancer.Nevertheless,many operations for gastrointestinal cancer treatment are still performed by open surgery.One reason for this may be the challenges of minimally invasive technology,especially when operating in narrow spaces,such as within the pelvis or near the upper edge of the pancreas.Moreover,some of the current literature has questioned oncologic outcomes after minimally invasive surgery for gastrointestinal cancer.Overall,the current evidence suggests that minimally invasive techniques are safe and feasible in gastrointestinal cancer surgery,but most of the studies published in this field are retrospective studies and casematched studies.Large-scale randomized prospective studies are needed to further support the application of minimally invasive surgery.In this review,we summarize several common minimally invasive methods used to treat gastrointestinal cancer and discuss the advances in the minimally invasive treatment of gastrointestinal cancer in detail.

Minimally invasive nephrectomy for inflammatory renal disease

Objective:Once chronic inflammatory renal disease(IRD)develops,it creates a severe peri-fibrotic process,which makes it a relative contraindication for minimally invasive surgery(MIS).Our objective is to show that laparoscopic nephrectomy(LN)is a surgical option in IRD with fewer complications and better outcomes.Methods:Retrospective review of patients who underwent a modified-surgical laparoscopic transperitoneal nephrectomy was performed.Data search included all operated patients between May 2013 and May 2018 that had a pathology result with any renal inflammatory condition(xanthogranulomatous pyelonephritis,chronic nephritis,and renal tuberculosis).We describe intra-operative variables such as operative time,blood loss,conversion rate,postoperative complications and length of hospital stay.Results:There were 51 patients who underwent laparoscopic nephrectomy with a confirmatory pathology report for IRD.We identified four(8%)major complications;three of them required transfusion and one conversion to open surgery.The mean operative time was 233108 min.Mean estimated blood loss was 206242 mL excluding the conversion cases and 281423 mL including them.The mean length of hospital stay was 3.02.0 days.Conclusion:Laparoscopic nephrectomy for IRD can safely be done.It is a reproducible technique with low risks and complication rates.Our experience supports that releasing the kidney first and leaving the hilum for the end is a safe approach when vascular structures are embedded into a single block of inflammatory and scar tissue.

Lymph node metastasis in early gastric cancer with submucosal invasion:Feasibility of minimally invasive surgery

AIM:To explore the feasibility of pertorming minimally invasive surgery(MIS)on subsets of submucosal gastric cancers that are unlikely to have regional lymph node metastasis. METHODS:A total of 105 patients underwent radical gastrectomy with lymph node dissection for submucosal gastric cancer at our hospital from January 1995 to December 1995.Besides investigating many clinicopathological features such as tumor size,gross appearance,and differentiation, we measured the depth of invasion into submucosa minutely and analyzed the clinicopathologic features of these patients regarding lymph node metastasis. RESULTS:The rate of lymph node metastasis in cases where the depth of invasion was<500 μm,500-2 000 μm,or >2 000 μm was 9%(2/23),19%(7136),and 33%(15/46), respectively(P<0.05).In univariate analysis,no significant correlation was found between lymph node metastasis and clinicopathological characteristics such as age,sex,tumor location,gross appearance,tumor differentiation,Lauren's classification,and lymphatic invasion.In multivariate analysis, tumor size(>4 cm vs≤2 cm,odds ratio=4.80, P=0.04)and depth of invasion(>2 000 μm vs ≤500 μm, odds ratio=6.81,P=0.02)were significantly correlated with lymph node metastasis.Combining the depth and size in cases where the depth of invasion was less than 500 μm, we found that lymph node metastasis occurred where the tumor size was greater than 4 cm.In cases where the tumor size was less than 2 cm,lymph node metastasis was found only where the depth of tumor invasion was more than 2 000 μm. CONCLUSION:MIS can be applied to submucosal gastric cancer that is less than 2 cm in size and 500 μm in depth.

Multi-Objective Optimization of the Ultrasonic Scalpel Rod and Tip with Improved Performance:Vibration Frequency,Amplitude,and Service Life

Ultrasonic scalpel design for minimally invasive surgical procedures is mainly focused on optimizing cutting performance.However,an important issue is the low fatigue life of traditional ultrasonic scalpels,which affects their long-term reliability and effectiveness and creates hidden dangers for surgery.In this study,a multi-objective optimal design for the cutting performance and fatigue life of ultrasonic scalpels was proposed using finite element analysis and fatigue simulation.The optimal design parameters of resonance frequency and amplitude were determined.By setting the transition fillet and keeping the gain structure away from the node position to enable the scalpel to have a high service life with excellent cutting performance.The frequency modulation method of setting the vibration node bosses at the node position and setting the vibration antinode grooves at the antinode position was compared.Then,the mechanism of the influence of various design elements,such as tip,shank,node position,and antinode position,on the resonance frequency,amplitude,and fatigue life of the ultrasonic scalpel was analyzed,and the optimal design principles of the ultrasonic scalpel were obtained.The proposed ultrasonic scalpel design was confirmed by simulations,impedance measurements,and liver tissue cutting experiments,demonstrating its feasibility and enhanced performance.This research introduces innovative design strategies to improve the fatigue life and performance of ultrasonic scalpels to address an important issue in minimally invasive surgery.

Precision at scale:Machine learning revolutionizing laparoscopic surgery

In their recent study published in the World Journal of Clinical Cases,the article found that minimally invasive laparoscopic surgery under general anesthesia demonstrates superior efficacy and safety compared to traditional open surgery for early ovarian cancer patients.This editorial discusses the integration of machine learning in laparoscopic surgery,emphasizing its transformative po-tential in improving patient outcomes and surgical precision.Machine learning algorithms analyze extensive datasets to optimize procedural techniques,enhance decision-making,and personalize treatment plans.Advanced imaging modalities like augmented reality and real-time tissue classification,alongside robotic surgical systems and virtual reality simulations driven by machine learning,enhance imaging and training techniques,offering surgeons clearer visualization and precise tissue manipulation.Despite promising advancements,challenges such as data privacy,algorithm bias,and regulatory hurdles need addressing for the responsible deployment of machine learning technologies.Interdisciplinary collaborations and ongoing technological innovations promise further enha-ncement in laparoscopic surgery,fostering a future where personalized medicine and precision surgery redefine patient care.

Minimally invasive multivisceral resection in rectal cancer:Preparation or Precipitation?

Rectal cancer is a malignant neoplasm that constitutes a significant public health challenge due to its high incidence and associated mortality.In this editorial,we comment on the article by Chan et al.In recent years,there has been progress in the development of new treatments for initial and metastatic rectal cancer due to introduction of techniques of innovative and minimally-invasive surgery(MIS)such as laparoscopy and robotic surgery.However,only a few studies have ana-lyzed the feasibility,safety,and results of MIS in relation to open surgery,thereby highlighting the promising and superior results of MIS in functional and oncolo-gical terms.The findings were corroborated by the comparative study of Chan et al which evaluated the feasibility and safety of minimally invasive multivisceral resection(miMVR).A comparison of postoperative outcomes between open MVR and miMVR showed that miMVR presented less blood loss,fewer postoperative complications,and less morbidity.This editorial article is focused specifically on analysis of the characteristics of new minimally-invasive surgical techniques in rectal cancer,particularly in advanced stages.The importance of future research is emphasized by progress in knowledge,training,and clinical practice in the appli-cation of these surgical procedures for the treatment of advanced colorectal cancer.

Current diagnostic tools and treatment modalities for rectal prolapse

Rectal prolapse is a circumferential,full-thickness protrusion of the rectum through the anus.It is a rare condition,and only affects 0.5%of the general population.Multiple treatment modalities have been described,which have changed significantly over time.Particularly in the last decade,laparoscopic and robotic surgical approaches with different mobilization techniques,combined with medical therapies,have been widely implemented.Because patients have presented with a wide range of complaints(ranging from abdominal discomfort to incomplete bowel evacuation,mucus discharge,constipation,diarrhea,and fecal incontinence),understanding the extent of complaints and ruling out differential diagnoses are essential for choosing a tailored surgical procedure.It is crucial to assess these additional symptoms and their severities using preoperative scoring systems.Additionally,radiological and physiological evaluations may explain some vague symptoms and reveal concomitant pelvic disorders.However,there is no consensus on or standardization of the optimal extent of dissection,type of procedure,and materials used for rectal fixation;this makes providing maximum benefits to patients with minimal complications difficult.Even recent publications and systematic reviews have not recommended the most appropriate treatment options.This review explains the appropriate diagnostic tools for different conditions and summarizes the current treatment approaches based on existing literature and expert opinions.

Current approach for Boerhaaves syndrome:A systematic review of case reports

There is no consensus on the appropriate therapeutic strategy for Boerhaave syndrome due to its rarity and changing therapeutic approaches.We conducted a systematic review of case reports documenting Boerhaave syndrome.AIM To assess the therapeutic methods and clinical outcomes and discuss the current trends in the management of Boerhaave syndrome.METHODS We searched PubMed,Google scholar,MEDLINE,and The Cochrane Library for studies concerning Boerhaave syndrome published between 2017 and 2022.RESULTS Of the included studies,49 were case reports,including a total of 56 cases.The mean age was 55.8±16 years old.Initial conservative treatment was performed in 25 cases,while operation was performed in 31 cases.The rate of conservative treatment was significantly higher than that of operation in cases of shock vital on admission(9.7%vs 44.0%;P=0.005).Seventeen out of 25 conservative cases(68.0%)were initially treated endoscopic esophageal stenting;2 of those 17 cases subsequently underwent operation due to poor infection control.Twelve cases developed postoperative leakage(38.7%),and 4 of those 12 cases underwent endoscopic esophageal stenting to stop the leakage.The length of the hospital stay was not significantly different between the conservative treatment and operation cases(operation vs conservation:33.52±22.69 vs 38.81±35.28 days;P=0.553).CONCLUSION In the treatment of Boerhaave syndrome,it is most important to diagnose the issue immediately.Primary repair with reinforcement is the gold-standard procedure.The indication of endoscopic esophageal stenting or endoluminal vacuum-assisted therapy should always be considered for patients in a poor general condition and who continue to have leakage after repair.

2011 update on esophageal achalasia

There have been some breakthroughs in the diagnosis and treatment of esophageal achalasia in the past few years.First,the introduction of high-resolution manometry with pressure topography plotting as a new diagnostic tool has made it possible to classify achalasia into three subtypes.The most favorable outcome is predicted for patients receiving treatment for type Ⅱ achalasia (achalasia with compression).Patients with typeⅠ(classic achalasia) and type Ⅲ achalasia (spastic achalasia) experience a less favorable outcome.Second,the first multicenter randomized controlled trial published by the European Achalasia Trial group reported 2-year follow-up results indicating that laparoscopic Heller myotomy was not superior to endoscopic pneumatic dilation (PD).Although the follow-up period was not long enough to reach a convincing conclusion,it merits the continued use of PD as a generally available technique in gastroenterology.Third,the novelendoscopic technique peroral endoscopic myotomy is a promising option for treating achalasia,but it requires increased experience and cautious evaluation.Despite all this good news,the bottom line is a real break-through from the basic studies to identify the actual cause of achalasia that may impede treatment success is still anticipated.

Laparoscopic surgery for gastric cancer:Current status and future direction

Gastric cancer is still a major cause of death worldwide.While laparoscopic gastrectomy(LG)has gained evidence as a standard treatment for early gastric cancer in the distal stomach,there are still concerns regarding its application for gastric cancer in the upper stomach and advanced gastric cancer.Nevertheless,LG has shown to have faster recovery,shorter hospital stay,less pain,and less blood loss in many retrospective and prospective studies.The application of LG has now extended from conventional radical gastrectomy to novel approaches such as function-preserving gastrectomy and sentinel-node navigated surgery.Studies on the use of laparoscopy in treatment for stage IV gastric cancer are rare,but show that there may be some roles of LG in selected cases.With the development of new laparoscopic tools that augment human ability,the future of LG should move on from proving non-inferiority to demonstrating superiority compared to the traditional open gastrectomy.

Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device： An Exploratory Feasibility Study in vitro

Background：A single drilled tunnel from the lateral mastoid cortex to the cochlea via the facial recess is essential for minimally invasive cochlear implant surgery.This study aimed to explore the safety profile of this kind of new image-guided and bi-planar device-assisted surgery procedure in vitro.Methods：Image-guided minimally invasive cochlear implantations were performed on eight cadaveric temporal bone specimens.The main procedures were：（1） temporal bone specimens were prepared for surgery and fiducial markers were registered.（2） computed tomography （CT） scans were performed for future reference.（3） CT scan images were processed and drill path was planned to minimize cochlear damage.（4） bi-planar device-assisted drilling was performed on the specimens using the registration.（5） surgical safety was evaluated by calculating the deviation between the drill and the planned paths,and by measuring the closest distance between the drilled path and critical anatomic structures.Results：Eight cases were operated successfully to the basal turn of the cochlear with intact facial nerves （FNs）.The deviations from target points and entrance points were 0.86 mm （0.68-1.00 mm） and 0.44 mm （0.30-0.96 mm）,respectively.The angular error between the planned and the drilled trajectory was 1.74° （1.26-2.41°）.The mean distance from the edge of the drilled path to the FN and to the external canal was 0.60 mm （0.35-0.83 mm） and 1.60 mm （1.30-2.05 mm）,respectively.In five specimens,the chorda tympani nerves were well preserved.In all cases,no injury happened to auditory ossicles.Conclusions：This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures.Further,more in vitro experiments are needed to improve the system operation and its safety.

经皮穿刺气管切开术并发症3例

气管切开术是头颈外科手术和抢救急危重症患者建立可靠人工气道必不可少的重要手段。经皮穿刺气管切开术（percutaneous dilational tracheostomy,PDT）是近年来广泛应用的临床微创抢救技术,具有方法简单、操作方便、出血少、对操作场地要求低等优点,逐渐被广大临床医师接受并推广,但PDT仍有部分患者出现严重并发症。现将我院急诊科、ICU应用PDT出现严重并发症的典型病例总结并加以讨论。