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.

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.

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.

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.

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.

Method for Latency Measurement of Visual Feedback-Based Master–Slave Minimally Invasive Surgical Robot

To measure the latency between human motion stimulation and stereo image display response in a visual feedback-based minimally invasive surgical(MIS) robotic system,a method was proposed by comparing the orientations of input and output events through image-processing technology. This method used a black bar to keep pace with the measured joint rotating at a number of speeds. During tests,an external camera was placed in front of the apparatus with a proper visual field,so that it can simultaneously view orientations of both bars fixed on the corresponding joints. After quantitatively analyzing the accuracy of the proposed measurement method,the method was applied to a visual feedback-based master–slave robotic system with two-degrees-of-freedom. Experimental results show that the latency of the overall system was approximately 250 ms,and the opposite clearance of the measured joint was in the range of 1.7°–1.9°.

Minimally Invasive Surgical Approach for Spinal Canal Tumors—Technique Description and Experience from a Reference Center

Background: Spinal canal tumors are difficult to diagnose and treat. The traditional surgical approaches for attempting a complete excision of these lesions frequently involve big incisions and tissue dissection with high risk of postop instability and cerebrospinal fluid leakage. Also, there is a risk of neurological worsening, sometimes irreversible. Methods: We present our experience in a patient series with spinal canal tumors and describe the surgical approach with minimally invasive techniques (MIS). All of them were performed by the Neurosurgery team of the Hospital Universitario San Ignacio during the period of 2011-2016. Results: We reviewed forty patients with spinal canal tumors surgically treated with MIS techniques. 15 patients (37.5%) had Meningioma diagnosis (complete resection in 11 (73.3%), subtotal in 3 (20%) and biopsy in one patient), 10 patients (25%) with Schwannomas reached complete resection in 70% and subtotal in 30%. 5 patients had spinal cord metastasis, with complete resection in 4 patients (80%) and subtotal in 1 (20%). Other included ependymoma, astrocytoma, and miscellaneous. No patient has had cerebrospinal fluid leakage and no postoperative fusion has been required. Conclusions: The minimally invasive approach allowed complete tumors removal in a high number of patients and good postoperative results. These findings are similar and in some cases, better than the reported with traditional techniques. This MIS technique provides encouraging results. It requires a wide learning curve and a high degree of surgical experience.

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.

Hand-Held Surgical Instrument with the Function of Self-Locking for Minimally Invasive Surgery

In order to improve the flexibility of the surgical instruments, a wire-driven wrist-like structure is proposed in this paper. The instrument has three degrees of freedom (DOFs) of rotation, yaw, opening and closing. Furthermore, we also acknowledge no coupling motion for each DOF. Moreover, the self-locking motion contributes to sustaining joint posture under external force. A static analysis for the end effector was conducted using the ANSYS software. At the end of this paper, a series of experiments for the prototype was performed. The results revealed that for the same surgical task, the proposed instrument had higher flexibility and the completion time of the operation tasks was obviously less than that of the traditional instrument. The results of the self-locking and operating force test showed that the surgical instruments perform well in maintaining joint posture under the force of 8.2N. The proposed surgical instrument meets the requirements of minimally invasive surgery (MIS).

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.

Lack of proper reimbursement is hampering adoption of minimally invasive gastrointestinal endoscopy in North America

Endoscopic submucosal dissection(ESD)and related procedures are minimally invasive and cost-effective alternates to surgery.However,there is no approved or listed current procedural terminology(CPT)for ESD.We aimed to review the current reimbursement process hurdles for ESD procedures in private practice model in United States.We reviewed the data of two advanced endoscopists(one in New York and other in Pennsylvania State)performing ESD in their private practice set-ups.We found the reimbursement process was complex,with number of refusals varied from 0-9 for ESD procedures.It was not paid at all in 8.3%of cases by the medical insurance.Endoscopic mucosal resection,which is considered inferior as compared to ESD,but has a listed CPT,was denied in only 0.83%cases.Our data highlights the billing hurdles by the endoscopists to adopt ESD-related procedures in private practice model.

Minimally invasive surgery vs laparotomy in patients with colon cancer residing in high-altitude areas

BACKGROUND Colon cancer is associated with a higher incidence among residents in highaltitude areas.Hypoxic environment at high altitudes inhibits the phagocytic and oxygen-dependent killing function of phagocytes,thereby increasing the inflammatory factors,inhibiting the body’s innate immunity and increasing the risk of colon cancer.AIM To examine the effect of minimally invasive surgery vs laparotomy in patients with colon cancer residing in high-altitude areas.METHODS Ninety-two patients with colon cancer in our hospital from January 2019 to February 2021 were selected and divided into the minimally invasive surgery and laparotomy groups using the random number table method,with 46 patients in each group.Minimally invasive surgery was performed in the minimally invasive group and laparotomy in the laparotomy group.Operative conditions,inflammatory index pre-and post-surgery,immune function index and complication probability were measured.RESULTS Operative duration was significantly longer and intraoperative blood loss and recovery time of gastrointestinal function were significantly less(all P<0.05)in the minimally invasive group than in the laparotomy group.The number of lymph nodes dissected was not significantly different.Before surgery,there were no significant differences in serum C-reactive protein,interleukin-6 and tumor necrosis factor-αlevels between the groups,whereas after surgery,the levels were significantly higher in the minimally invasive group(26.98±6.91 mg/L,146.38±11.23 ng/mL and 83.51±8.69 pg/mL vs 41.15±8.39 mg/L,186.79±15.36 ng/mL and 110.65±12.84 pg/mL,respectively,P<0.05).Furthermore,before surgery,there were no significant differences in CD3+,CD4+and CD4+/CD8+levels between the groups,whereas after surgery,the levels decreased in both groups,being significantly higher in the minimally invasive group(55.61%±4.39%,35.45%±3.67%and 1.30±0.35 vs 49.68%±5.33%,31.21%±3.25%and 1.13±0.30,respectively,P<0.05).Complication probability was significantly lower in the minimally invasive group(4.35%vs 17.39%,P<0.05).CONCLUSION Laparoscopic minimally invasive procedures reduce surgical trauma and alleviate the inflammatory response and immune dysfunction caused by invasive operation.It also shortens recovery time and reduces complication probability.

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

Minimally invasive surgery(MIS) for upper gastro-intestinal(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.

Updated experiences with minimally invasive Mc Keown esophagectomy for esophageal cancer

AIM: To update our experiences with minimally invasive Mc Keown esophagectomy for esophageal cancer.METHODS: we retrospectively reviewed the medical records of 445 consecutive patients who underwent minimally invasive Mc Keown esophagectomy between January 2009 and July 2015 at the Cancer Hospital of Chinese Academy of Medical Sciences and used 103 patients who underwent open Mc Keown esophagectomy in the same period as controls. Among 375 patients who underwent total minimally invasive Mc Keown esophagectomy, 180 in the early period were chosen for the study of learning curve of total minimally invasive Mc Keown esophagectomy. These 180 minimally invasive Mc Keown esophagectomies performed by five surgeons were divided into three groups according to time sequence as group 1(n = 60), group 2(n = 60) and group 3(n = 60).RESULTS: Patients who underwent total minimally invasive Mc Keown esophagectomy had significantly less intraoperative blood loss than patients who underwent hybrid minimally invasive Mc Keown esophagectomy or open Mc Keown esophagectomy(100 ml vs 300 ml vs 200 ml, P = 0.001). However, there were no significant differences in operation time, number of harvested lymph nodes, or postoperative morbidity includingincidence of pulmonary complication and anastomotic leak between total minimally invasive Mc Keown esophagectomy, hybrid minimally invasive Mc Keown esophagectomy and open Mc Keown esophagectomy groups. There were no significant differences in 5-year survival between these three groups(60.5% vs 47.9% vs 35.6%, P = 0.735). Patients in group 1 had significantly longer duration of operation than those in groups 2 and 3. There were no significant differences in intraoperative blood loss, number of harvested lymph nodes, or postoperative morbidity including incidence of pulmonary complication and anastomotic leak between groups 1, 2 and 3.CONCLUSION: Total minimally invasive Mc Keown esophagectomy was associated with reduced intraoperative blood loss and comparable short term and long term survival compared with hybrid minimally invasive Mc Keown esophagectomy or open Mckeown esophagectomy. At least 12 cases are needed to master total minimally invasive Mc Keown esophagectomy in a high volume center.

Non-robotic minimally invasive gastrectomy as an independent risk factor for postoperative intra-abdominal infectious complications: A single-center, retrospective and propensity score-matched analysis

BACKGROUND Minimally invasive surgery for gastric cancer(GC) has gained widespread use as a safe curative procedure especially for early GC.AIM To determine risk factors for postoperative complications after minimally invasive gastrectomy for GC.METHODS Between January 2009 and June 2019, 1716 consecutive patients were referred to our division for primary GC. Among them, 1401 patients who were diagnosed with both clinical and pathological Stage Ⅲ or lower GC and underwent robotic gastrectomy(RG) or laparoscopic gastrectomy(LG) were enrolled. Retrospective chart review and multivariate analysis were performed for identifying risk factors for postoperative morbidity.RESULTS Morbidity following minimally invasive gastrectomy was observed in 7.5% of the patients. Multivariate analyses demonstrated that non-robotic minimally invasive surgery, male gender, and an operative time of ≥ 360 min were significant independent risk factors for morbidity. Therefore, morbidity was compared between RG and LG. Accordingly, propensity-matched cohort analysis revealed that the RG group had significantly fewer intra-abdominal infectious complications than the LG group(2.5% vs 5.9%, respectively;P = 0.038), while no significant differences were noted for other local or systemic complications.Multivariate analyses of the propensity-matched cohort revealed that non-robotic minimally invasive surgery [odds ratio = 2.463(1.070–5.682);P = 0.034] was a significant independent risk factor for intra-abdominal infectious complications.CONCLUSION The findings showed that robotic surgery might improve short-term outcomes following minimally invasive radical gastrectomy by reducing intra-abdominal infectious complications.

Incidence of surgical site infection in minimally invasive colorectal surgery

BACKGROUND Surgical site infection(SSI)is a common complication of colorectal surgery.Minimally invasive surgery notably reduces the incidence of SSI.This study aimed to compare the incidences of SSI after robot-assisted colorectal surgery(RACS)vs that after laparoscopic assisted colorectal surgery(LACS)and to analyze associated risk factors for SSI in minimally invasive colorectal surgery.AIM To compare the incidences of SSI after RACS and LACS,and to analyze the risk factors associated with SSI after minimally invasive colorectal surgery.METHODS Clinical data derived from patients who underwent minimally invasive colorectal surgery between October 2020 and October 2022 at the First Affiliated Hospital of Soochow University were collated.Differences in clinical characteristics and surgeryrelated information associated with RACS and LACS were compared,and possible risk factors for SSI were identified.RESULTS A total of 246 patients(112 LACS and 134 RACS)were included in the study.Fortythree(17.5%)developed SSI.The proportions of patients who developed SSI were similar in the two groups(17.9%vs 17.2%,P=0.887).Diabetes mellitus,intraoperative blood loss≥100 mL,and incision length were independent risk factors for SSI.Possible additional risk factors included neoadjuvant therapy,lesion site,and operation time.CONCLUSION There was no difference in SSI incidence in the RACS and LACS groups.Diabetes mellitus,intraoperative blood loss≥100 mL,and incision length were independent risk factors for postoperative SSI.

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

AIM:To explore the feasibility of performing minimally invasive surgery(MIS) on subsets of submucosal gastric cancers that are unlikely to have regional lymph node metastasis.METHOPS: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<500μm,500-200μm,or>2000μm was 9% (2/23),19%(7/36),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(>4cm vs≤2cm,odds ratio=4。80,P=0.04)and depth of invasion(>2000μm vs ≤500μm,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 500μm,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 2000μm.CONCLUSION:MIS can be applied to submucosal gastric cancer that is less than 2 cm in size and 500μm in depth.

Recent advances in minimally invasive total hip replacement surgery approaches

Minimally invasive surgery is a technology that has been seeking breakthroughs in surgery.It is a common goal of both doctors and patients.At present,artificial hip arthroplasty has been in clinical application for more than fifty years,and has been fully affirmed.In recent years,minimally invasive techniques have been applied more clinically.And minimally invasive has the advantages of less bleeding,early postoperative activities and more are accepted by more and more surgeons.However,the current minimally invasive total hip replacement approach is different.This article reviews the approaches and advantages and disadvantages of the minimally invasive artificial hip joint replacements currently used in the clinic in order to provide new ideas for clinical minimally invasive total hip replacement.

A Novel Tele-Operated Flexible Robot Targeted for Minimally Invasive Robotic Surgery

In this paper, a novel flexible robot system with a constrained tendon-driven serpentine manipulator(CTSM) is presented. The CTSM gives the robot a larger workspace, more dexterous manipulation, and controllable stiffness compared with the da Vinci surgical robot and traditional flexible robots. The robot is tele-operated using the Novint Falcon haptic device. Two control modes are implemented, direct mapping and incremental mode. In each mode, the robot can be manipulated using either the highest stiffness scheme or the minimal movement scheme. The advantages of the CTSM are shown by simulation and experimental results.