New direction for surgery:Super minimally invasive surgery

The top goal of modern medicine is treating disease without destroying organ structures and making patients as healthy as they were before their sickness.Minimally invasive surgery(MIS)has dominated the surgical realm because of its lesser invasiveness.However,changes in anatomical structures of the body and reconstruction of internal organs or different organs are common after traditional surgery or MIS,decreasing the quality of life of patients post-operation.Thus,I propose a new treatment mode,super MIS(SMIS),which is defined as“curing a disease or lesion which used to be treated by MIS while preserving the integrity of the organs”.In this study,I describe the origin,definition,operative channels,advantages,and future perspectives of SMIS.

Efficacy and safety of minimally invasive laparoscopic surgery under general anesthesia for ovarian cancer

BACKGROUND Ovarian cancer is one of the most common malignant tumors in female reproductive system in the world,and the choice of its treatment is very important for the survival rate and prognosis of patients.Traditional open surgery is the main treatment for ovarian cancer,but it has the disadvantages of big trauma and slow recovery.With the continuous development of minimally invasive technology,minimally invasive laparoscopic surgery under general anesthesia has been gradually applied to the treatment of ovarian cancer because of its advantages of less trauma and quick recovery.However,the efficacy and safety of minimally invasive laparoscopic surgery under general anesthesia in the treatment of ovarian cancer are still controversial.AIM To explore the efficacy and safety of general anesthesia minimally invasive surgery in the treatment of ovarian cancer.METHODS The clinical data of 90 patients with early ovarian cancer in our hospital were analyzed retrospectively.According to the different surgical treatment methods,patients were divided into study group and control group(45 cases in each group).The study group received minimally invasive laparoscopic surgery under general anesthesia for ovarian cancer,while the control group received traditional open surgery for ovarian cancer.The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire(EORTC QLQ-C30),clinical efficacy and safety of the two groups were compared.RESULTS The intraoperative blood loss,length of hospital stay,postoperative gas evacuation time,and postoperative EORTC QLQ-C30 score of the study group were significantly better than those of the control group(P<0.05).The incidence of postoperative complications in the study group was significantly lower than in the control group(P<0.05).The two groups had no significant differences in the preoperative adrenocorticotropic hormone(ACTH),androstenedione(AD),cortisol(Cor),cluster of differentiation 3 positive(CD3+),and cluster of differentiation 4 positive(CD4+)indexes(P>0.05).In contrast,postoperatively,the study group's ACTH,AD,and Cor indexes were lower,and the CD3+and CD4+indexes were higher than those in the control group(P<0.05).CONCLUSION Minimally invasive laparoscopic surgery under general anesthesia in patients with early ovarian cancer can significantly improve the efficacy and safety,improve the short-term prognosis and quality of life of patients,and is worth popularizing.

Exploring the landscape of minimally invasive pancreatic surgery: Progress, challenges, and future directions

Minimally invasive surgery(MI)has become the standard of care for many surgical procedures aimed at reducing the burden on patients.However,its adoption in pancreatic surgery(PS)has been limited by the pancreas’s unique location and the complexity of the dissection and reconstruction phases.These factors continue to contribute to PS having one of the highest morbidity and mortality rates in general surgery.Despite a rough start,MIPS has gained widespread acceptance in clinical practice recently.Robust evidence supports MI distal pancreatectomy safety,even in oncological cases,indicating its potential superiority over open surgery.However,definitive evidence of MI pancre-aticoduodenectomy(MIPD)feasibility and safety,particularly for malignant lesions,is still lacking.Nonetheless,reports from high-volume centers are emer-ging,suggesting outcomes comparable to those of the open approach.The robotic PS increasing adoption,facilitated by the wider availability of robotic platforms,may further facilitate the transition to MIPD by overcoming the technical con-straints associated with laparoscopy and accelerating the learning curve.Alth-ough the MIPS implementation process cannot be stopped in this evolving world,ensuring patient safety through strict outcome monitoring is critical.Investing in younger surgeons with structured and recognized training programs can promote safe expansion.

Impact of minimally invasive surgery on immune function and stress response in gastric cancer patients

BACKGROUND Gastric cancer remains a leading cause of cancer-related mortality globally.Traditional open surgery for gastric cancer is often associated with significant morbidity and prolonged recovery.AIM To evaluate the effectiveness of laparoscopic minimally invasive surgery as an alternative to traditional open surgery for gastric cancer,focusing on its potential to reduce trauma,accelerate recovery,and achieve comparable oncological out-comes.METHODS This study retrospectively analyzed 203 patients with gastric cancer who underwent surgery at the Shanghai Health Medical College Affiliated Chongming Hospital from January 2020 to December 2023.The patients were divided into two groups:Minimally invasive surgery group(n=102),who underwent laparoscopic gastrectomy,and open surgery group(n=101),who underwent traditional open gastrectomy.We compared surgical indicators(surgical incision size,intraop-erative blood loss,surgical duration,and number of lymph nodes dissected),recovery parameters(time to first flatus,time to start eating,time to ambulation,and length of hospital stay),immune function(levels of IgA,IgG,and IgM),intestinal barrier function(levels of D-lactic acid and diamine oxidase),and stress response(levels of C-reactive protein,interleukin-6,and procalcitonin).RESULTS The minimally invasive surgery group demonstrated significantly better outcomes in terms of surgical indicators,including smaller incisions,less blood loss,shorter surgery time,and more lymph nodes dissected(P<0.05 for all).Recovery was also faster in the minimally invasive surgery group,with earlier return of bowel function,earlier initiation of diet,quicker mobilization,and shorter hospital stays(P<0.05 for all).Furthermore,patients in the minimally invasive surgery group had better preserved immune function,superior intestinal barrier function,and a less pronounced stress response postoperatively(P<0.05 for all).CONCLUSION Laparoscopic minimally invasive surgery for gastric cancer not only provides superior surgical indicators and faster recovery but also offers advantages in preserving immune function,protecting intestinal barrier function,and mitigating the stress response compared to traditional open surgery.These findings support the broader adoption of laparoscopic techniques in the management of gastric cancer.

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.

Traditional craniotomy versus current minimally invasive surgery for spontaneous supratentorial intracerebral haemorrhage:A propensity-matched analysis

BACKGROUND Minimally invasive surgery(MIS)and craniotomy(CI)are the current treatments for spontaneous supratentorial cerebral haemorrhage(SSTICH).AIM To compare the efficacy and safety of MIS and CI for the treatment of SSTICH.METHODS Clinical and imaging data of 557 consecutive patients with SSTICH who underwent MIS or CI between January 2017 and December 2022 were retrospectively analysed.The patients were divided into two subgroups:The MIS group and CI group.Propensity score matching was performed to minimise case selection bias.The primary outcome was a dichotomous prognostic(favourable or unfavourable)outcome based on the modified Rankin Scale(mRS)score at 3 months;an mRS score of 0–2 was considered favourable.RESULTS In both conventional statistical and binary logistic regression analyses,the MIS group had a better outcome.The outcome of propensity score matching was unexpected(odds ratio:0.582;95%CI:0.281–1.204;P=0.144),which indicated that,after excluding the interference of each confounder,different surgical modalities were more effective,and there was no significant difference in their prognosis.CONCLUSION Deciding between MIS and CI should be made based on the individual patient,considering the hematoma size,degree of midline shift,cerebral swelling,and preoperative Glasgow Coma Scale score.

Lymph node dissection in esophageal carcinoma: Minimally invasive esophagectomy vs open surgery

AIM: To compare lymph node dissection results of minimally invasive esophagectomy(MIE) and open surgery for esophageal squamous cell carcinoma.METHODS: We retrospectively reviewed data from patients who underwent MIE or open surgery for esophageal squamous cell carcinoma from January 2011 to September 2014. Number of lymph nodes resected, positive lymph node(p N+) rate, lymph node sampling(LNS) rate and lymph node metastatic(LNM) rate were evaluated. R E S U LT S : A m o n g 4 4 7 p a t i e n t s i n c l u d e d, 1 2 3 underwent MIE and 324 underwent open surgery. The number of lymph nodes resected did not significantly differ between the MIE and open surgery groups(21.1 ± 4.3 vs 20.4 ± 3.8, respectively, P = 0.0944). The p N+ rate of stage T3 esophageal squamous cell carcinoma in the open surgery group was higher than that in the MIE group(16.3% vs 11.4%, P = 0.031), but no differences was observed for stages T1 and T2 esophageal squamous cell carcinoma. The LNS rate at left para-recurrent laryngeal nerve(RLN) site was significantly higher for open surgery than for MIE(80.2% vs 43.9%, P < 0.001), but no differences were noted at other sites. The LNM rate at left para-RLN site in the open surgery group was significantly higher than that in the MIE group, regardless of pathologic T stage. CONCLUSION: For stages T1 and T2 esophageal squamous cell carcinoma, the lymph node dissection result after MIE was comparable to that achieved by open surgery. However, the efficacy of MIE in lymphadenectomy for stage T3 esophageal squamous cell carcinoma, particularly at left para-RLN site, remains to be improved.

Minimally invasive surgery for gastric cancer: A comparison between robotic, laparoscopic and open surgery

AIM To investigate the role of minimally invasive surgery for gastric cancer and determine surgical, clinical, and oncological outcomes.METHODS This is a propensity score-matched case-control study, comparing three treatment arms: robotic gastrectomy(RG), laparoscopic gastrectomy(LG), open gastrectomy(OG). Data collection started after sharing a specific study protocol. Data were recorded through a tailored and protected web-based system. Primary outcomes: harvested lymph nodes, estimated blood loss, hospital stay, complications rate. Among the secondary outcomes, there are: operative time, R0 resections, POD of mobilization, POD of starting liquid diet and soft solid diet. The analysis includes the evaluation of type and grade of postoperative complications. Detailed information of anastomotic leakages is also provided.RESULTS The present analysis was carried out of 1026 gastrectomies. To guarantee homogenous distribution of cases, patients in the RG, LG and OG groups were 1:1:2 matched using a propensity score analysis with a caliper = 0.2. The successful matching resulted in a total sample of 604 patients(RG = 151; LG = 151; OG = 302). The three groups showed no differences in all baseline patients characteristics, type of surgery(P = 0.42) and stage of the disease(P = 0.16). Intraoperative blood loss was significantly lower in the LG(95.93 ± 119.22) and RG(117.91 ± 68.11) groups compared to the OG(127.26 ± 79.50, P = 0.002). The mean number of retrieved lymph nodes was similar between the RG(27.78 ± 11.45), LG(24.58 ± 13.56) and OG(25.82 ± 12.07) approach. A benefit in favor of the minimally invasive approaches was found in the length of hospital stay(P < 0.0001). A similar complications rate was found(P = 0.13). The leakage rate was not different(P = 0.78) between groups.CONCLUSION Laparoscopic and robotic surgery can be safely performed and proposed as possible alternative to open surgery. The main highlighted benefit is a faster postoperative functional recovery.

Surgical specimen extraction via a prophylactic ileostomy procedure: A minimally invasive technique for laparoscopic rectal cancer surgery

AIM To retrospectively evaluate the safety and feasibility of surgical specimen extraction via a prophylactic ileostomy procedure in patient with rectal cancer. METHODS We systematically reviewed 331 consecutive patients who underwent laparoscopic anterior resection for rectal cancer and prophylactic ileostomy in our institution from June 2010 to October 2016, including 155 patients who underwent specimen extraction via a prophylactic ileostomy procedure(experimental group), and 176 patients who underwent specimen extraction via a small lower abdominal incision(control group). Clinical data were collected from both groups andstatistically analyzed. RESULTS The two groups were matched in clinical characteristics and pathological outcomes. However, mean operative time was significantly shorter in the experimental group compared to the control group(161.3 ± 21.5 min vs 168.8 ± 20.5 min; P = 0.001). Mean estimated blood loss was significantly less in the experimental group(77.4 ± 30.7 mL vs 85.9 ± 35.5 mL; P = 0.020). The pain reported by patients during the first two days after surgery was significantly less in the experimental group than in the control group. No wound infections occurred in the experimental group, but 4.0% of the controls developed wound infections(P = 0.016). The estimated 5-year disease-free survival and overall survival rate were similar between the two groups.CONCLUSION Surgical specimen extraction via a prophylactic ileostomy procedure represents a secure and feasible approach to laparoscopic rectal cancer surgery, and embodies the principle of minimally invasive surgery.

Prognostic value of intracranial pressure monitoring for the management of hypertensive intracerebral hemorrhage following minimally invasive surgery

BACKGROUND:The incidence of hypertensive intracerebral hemorrhage(HICH)has been increasing during the recent years in low-and middle-income countries.With high mortality and morbidity rates,it brings huge burden to the families.It lacks evidence regarding the application of intracranial pressure(ICP)monitoring in HICH.In the current study,the authors aimed to evaluate whether ICP monitoring could make any difference on the prognosis of HICH patients after minimally invasive surgery.METHODS:A retrospective review of 116 HICH patients admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine,between 2014 and 2016,was performed.The effects of ICP monitoring on 6-month mortality and favorable outcomes were evaluated by univariate and logistic regression analysis.RESULTS:ICP monitors were inserted into 50 patients.Patients with ICP monitoring had a significantly better outcome(P<0.05).The average in-hospital duration in patients with ICP monitoring was shorter than that in the patients without ICP monitoring(16.68 days vs.20.47 days,P<0.05).Mortality rates between ICP monitoring and no ICP monitoring did not differ significantly(16.0%vs.15.1%,P=0.901).On univariate analysis,age,Glasgow Coma Scale(GCS)on admission and presence of ICP monitor were independent predictors of 6-month favorable outcomes.CONCLUSION:ICP monitoring is associated with a better 6-month functional outcome compared with no ICP monitoring.Future study is still needed to confirm our results and elucidate which subgroup of HICH patients will benefit most from the minimally invasive surgical intervention and ICP monitoring.

Minimally invasive surgery for submucosal(subepithelial) tumors of the stomach

Minimally invasive surgery has become common in the surgical resection of gastrointestinal submucosal tumors(SMTs). The purpose of this article is to review recent trends in minimally invasive surgery for gastric SMTs. Although laparoscopic resection has been main stream of minimally invasive surgery for gastrointestinal SMTs, recent advances in endoscopic procedures now provide various treatment modalities for gastric SMTs. Moreover, investigators have developed several hybrid techniques that include the advantages of both laparoscopic and endoscopic procedure. In addition, several types of reduced port surgeries, modification of conventional laparoscopic procedures, have been recently applied to the surgical resection of SMTs. Meanwhile, robotic surgery for SMTs requires further evidence and improvement.

The impact of minimally invasive surgeries for the treatment of symptomatic benign prostatic hyperplasia on male sexual function： a systematic review

A systematic review of randomized controlled trials and cohort studies was conducted to evaluate data for the effects of minimally invasive procedures for treatment of symptomatic benign prostatic hyperplasia （BPH） on male sexual function. The studies searched were trials that enrolled men with symptomatic BPH who were treated with laser surgeries, transurethral microwave therapy （TUMT）, transurethral needle ablation of the prostate （TUNA）, transurethral ethanol ablation of the prostate （TEAP） and high-intensity frequency ultrasound （HIFU）, in comparison with traditional transurethral resection of the prostate （TURP） or sham operations. A total of 72 studies were identified, of which 33 met the inclusion criteria. Of the 33 studies, 21 were concerned with laser surgeries, six with TUMT, four with TUNA and two with TEAP containing information regarding male sexual function. No study is available regarding the effect of HIFU for BPH on male sexual function. Our analysis shows that minimally invasive surgeries for BPH have comparable effects to those of TURP on male erectile function. Collectively, less than 15.4% or 15.2% of patients will have either decrease or increase, respectively, of erectile function after laser procedures, TUMT and TUNA. As observed with TURP, a high incidence of ejaculatory dysfunction （EjD） is common after treatment of BPH with holmium, potassium-titanyl-phosphate and thulium laser therapies （〉 33.6%）. TUMT, TUNA and neodymium：yttrium aluminum garnet visual laser ablation or interstitial laser coagulation for BPH has less incidence of EjD, but these procedures are considered less effective for BPH treatment when compared with TURP.

Minimally invasive surgery in gastric cancer

Minimally invasive surgery for gastric cancer has rapidly gained popularity due to the early detection of early gastric cancer. As advances in instruments and the accumulation of laparoscopic experience increase, laparoscopic techniques are being used for less invasive but highly technical procedures. Recent evidence suggests that the short- and long-term outcomes of minimally invasive surgery for early gastric cancer and advanced gastric cancer are comparable to those of conventional open surgery. However, these results should be confirmed by large-scale multicenter prospective randomized controlled clinical trials.

Role of minimally invasive surgery for rectal cancer

Rectal cancer is one of the most common malignancies worldwide.Surgical resection for rectal cancer usually requires a proctectomy with respective lymphadenectomy(total mesorectal excision).This has traditionally been performed transabdominally through an open incision.Over the last thirty years,minimally invasive surgery platforms have rapidly evolved with the goal to accomplish the same quality rectal resection through a less invasive approach.There are currently three resective modalities that complement the traditional open operation:(1)Laparoscopic surgery;(2)Robotic surgery;and(3)Transanal total mesorectal excision.In addition,there are several platforms to carry out transluminal local excisions(without lymphadenectomy).Evidence on the various modalities is of mixed to moderate quality.It is unreasonable to expect a randomized comparison of all options in a single trial.This review aims at reviewing in detail the various techniques in regard to intra-/perioperative benchmarks,recovery and complications,oncological and functional outcomes.

Short-term effect and long-term prognosis of neuroendoscopic minimally invasive surgery for hypertensive int-racerebral hemorrhage

BACKGROUND Hypertensive intracerebral hemorrhage is a common critical disease of the nervous system,comprising one fifth of all acute cerebrovascular diseases and has a high disability and mortality rate.It severely affects the patients’quality of life.AIM To analyze the short-term effect and long-term prognosis of neuroendoscopic minimally invasive surgery for hypertensive intracerebral hemorrhage.METHODS From March 2018 to May 2020,118 patients with hypertensive intracerebral hemorrhage were enrolled in our study and divided into a control group and observation group according to the surgical plan.The control group used a hard-channel minimally invasive puncture and drainage procedure.The observation group underwent minimally invasive neuroendoscopic surgery.The changes in the levels of serum P substances(SP),inflammatory factors[tumor necrosis factor-α,interleukin-6(IL-6),IL-10],and the National Hospital Stroke Scale(NIHSS)and Barthel index scores were recorded.Surgery related indicators and prognosis were compared between the two groups.RESULTS The operation time(105.26±28.35)of the observation group was min longer than that of the control group,and the volume of intraoperative bleeding was 45.36±10.17 mL more than that of the control group.The hematoma clearance rates were 88.58%±4.69%and 94.47%±4.02%higher than those of the control group at 48 h and 72 h,respectively.Good prognosis rate(86.44%)was higher in the observation group than in the control group,and complication rate(5.08%)was not significantly different from that of the control group(P>0.05).The SP level and Barthel index score of the two groups increased(P<0.05)and the inflam-matory factors and NIHSS score decreased(P<0.05).The cytokine levels,NIHSS score,and Barthel index score were better in the observation group than in the control group(P<0.05).CONCLUSION Neuroendoscopic minimally invasive surgery is more complicated than hard channel minimally invasive puncture drainage in the treatment of hypertensive intracerebral hemorrhage;however,hematoma clearance is more thorough,and the short-term effect and long-term prognosis are better than hard channel minimally invasive puncture drainage.

Three-dimensional(3D) Printing Technology Assisted by Minimally Invasive Surgery for Pubic Rami Fractures

The feasibility of three-dimensional (3D) printing technology cgmbined with minimally invasive surgery in the treatment of pubic rami fractures was explored.From August 2015 to October 2017,a series of 30 patients who underwent surgical stabilization of their anterior pelvic ring (all utilizing the 3D printing technology)by one surgeon at a single hospital were studied.The minimally invasive incisions were made through anterior inferior cilia spine and pubic nodule.Data collected included the operative duration,the blood loss,the damage of the important tissue,the biographic union and therecovery of the function after the operation.Measurements on inlet and outlet pelvic cardiograph were made immediately post-operation and at all follow-up clinic visits.The scores of reduction and function were measured during follow-up.Results showed that the wounds of 30 patients were healed in the first stage,and there was no injury of important structures such as blood vessels and nerves.According to the Matta criteria,excellent effectiveness was obtained in 22 cases and good in 8 cases.According to the functional evaluation criteria of Majeed,excellent effectiveness was obtained in 21 cases and good in 9 cases.It was suggested that the 3D printing technology assisted by minimally invasive surgery can better evaluate the pelvic fracture before operation,which was helpful in plate modeling, and can shorten surgery duration and reduce intraoperative blood loss and complications. The positioning accuracy was improved,and better surgical result was finally achieved.

Economic impact of minimally invasive lumbar surgery

Cost effectiveness has been demonstrated for traditional lumbar discectomy, lumbar laminectomy as well as for instrumented and noninstrumented arthrodesis. While emerging evidence suggests that minimally invasive spine surgery reduces morbidity, duration of hospitalization, and accelerates return to activites of daily living, data regarding cost effectiveness of these novel techniques is limited. The current study analyzes all available data on minimally invasive techniques for lumbar discectomy, decompression, short-segment fusion and deformity surgery. In general, minimallyinvasive spine procedures appear to hold promise in quicker patient recovery times and earlier return to work. Thus, minimally invasive lumbar spine surgery appears to have the potential to be a cost-effective intervention. Moreover, novel less invasive procedures are less destabilizing and may therefore be utilized in certain indications that traditionally required arthrodesis procedures. However, there is a lack of studies analyzing the economic impact of minimally invasive spine surgery. Future studies are necessary to confirm the durability and further define indications for minimally invasive lumbar spine procedures.

Association of Satellite Sign with Postoperative Rebleeding in Patients Undergoing Stereotactic Minimally Invasive Surgery for Hypertensive Intracerebral Haemorrhage

There are few studies regarding imaging markers for predicting postoperative rebleeding after stereotactic minimally invasive surgery(MIS)for hypertensive intracerebral haemorrhage(ICH),and little is known about the relationship between satellite sign on computed tomography(CT)scans and postoperative rebleeding after MIS.This study aimed to determine the value of the CT satellite sign in predicting postoperative rebleeding in patients with hypertensive ICH who undergo stereotactic MIS.We retrospectively examined and analysed 105 patients with hypertensive ICH who underwent standard stereotactic MIS for hematoma evacuation within 72 h following admission.Postoperative rebleeding occurred in 14 of 65(21.5%)patients with the satellite sign on baseline CT,and in 5 of the 40(12.5%)patients without the satellite sign.This diiTerence was statistically significant.Positive and negative values of the satellite sign for predicting postoperative rebleeding were 21.5%and 87.5%,respectively.Multivariate logistic regression analysis verified that baseline ICH volume and intraventricular rupture were independent predictors of postoperative rebleeding.In conclusion,the satellite sign on baseline CT scans may not predict postoperative rebleeding following stereotactic MIS for hypertensive ICH.

Multi-optimizationofasphericalmechanismforminimallyinvasivesurgery

In order to obtain the remote center motion(RCM) mechanism with better performance indexes and avoid the collision of multi-manipulators in minimally invasive surgery(MIS), a novel multi-objective optimization model was presented. There were two optimization objectives: a global kinematic performance index and a comprehensive stiffness index. Other indexes to characterize the design requirements such as collision probability, workspace, mechanism parameter, mass, and wall thickness were considered as constraints. Angles between two adjacent joints and cross-section dimensions of links were chosen as the design variables. The non-dominated sorting genetic algorithm II(NSGA-II) was adopted to solve the complex multi-objective optimization problem. Then, a 3-degree of freedom(DoF) MIS robotic prototype based on optimization results has been built up. The experiments to test the spatial position change of the remote center point and to test the absolute position accuracy and repetitive position accuracy of the MIS robot were achieved, and the experimental results meet the requirements of MIS.

Comparison of clinical outcomes and postoperative recovery between two open heart surgeries:minimally invasive right subaxillary vertical thoracomy and traditional median sternotomy

Objective: To compare the clinical outcomes of minimally invasive right subaxillary vertical thoracotomy and traditional median stemotomy through right atrium in treatment of common congenital heart diseases. Methods: Clinical data of 59 cases of common congenital heart diseases treated with minimally invasive right axillary vertical thoracotomy from May, 2011 to February, 2013 and 77 cases of same diseases with traditional median stemotomy in the past three years were retrospectively analyzed, including atrial septal defect, membranous ventricular septal defect and partial endocardial cushion defect. The results were compared from the two groups, including the time for operation and cardiopulmonary bypass, amount of blood transfusion, postoperative drainage, ventilation time, hospital stay, and prognosis. Results: No severe complications happened in both groups, like deaths or secondary surgery caused by bleeding. No significant differences were in CPB time and postoperative ventilator time between groups (P>0.05), while for all of the operative time, the length of incision, postoperative drainage and hospital stay, minimally invasive right axillary vertical thoracotomy was superior to median stemotomy, with statistically significant differences (P<0.05). In six month followup after operation, no complications of residual deformity and pericardial effusion were found in both groups by doing echocardiography, but mild pectus carinatum was found in 8 patients in the traditional median sternotomy group (traditional group), whereas patients in another group were well recovered. Conclusions: Minimally invasive right subaxillary vertical thoracotomy for common congenital heart diseases is as safe as traditional median stemotomy, without the increasing incidence of postoperative complications. Additionally, compared with traditional median stemotomy, minimally - invasive right subaxillary vertical thoracotomy is better in the aspects of hidden incision, appearance, and postoperative recovery.