Evaluation status of current and emerging minimally invasive robotic surgical platforms

BACKGROUND

The rapid adoption of robotics within minimally invasive surgical specialties has also seen an explosion of new technology including multi- and single port, natural orifice transluminal endoscopic surgery (NOTES), endoluminal and "on-demand" platforms. This review aims to evaluate the validation status of current and emerging MIS robotic platforms, using the IDEAL Framework.

METHODS

A scoping review exploring robotic minimally invasive surgical devices, technology and systems in use or being developed was performed, including general surgery, gynaecology, urology and cardiothoracics. Systems operating purely outside the abdomen or thorax and endoluminal or natural orifice platforms were excluded. PubMed, Google Scholar, journal reports and information from the public domain were collected. Each company was approached via email for a virtual interview to discover more about the systems and to quality check data. The IDEAL Framework is an internationally accepted tool to evaluate novel surgical technology, consisting of four stages: idea, development/exploration, assessment, and surveillance. An IDEAL stage, synonymous with validation status in this review, was assigned by reviewing the published literature.

RESULTS

21 companies with 23 different robotic platforms were identified for data collection, 13 with national and/or international regulatory approval. Of the 17 multiport systems, 1 is fully evaluated at stage 4, 2 are stage 3, 6 stage 2b, 2 at stage 2a, 2 stage 1, and 4 at the pre-IDEAL stage 0. Of the 6 single-port systems none have been fully evaluated with 1 at stage 3, 3 at stage 1 and 2 at stage 0.

CONCLUSIONS

The majority of existing robotic platforms are currently at the preclinical to developmental and exploratory stage of evaluation. Using the IDEAL framework will ensure that emerging robotic platforms are fully evaluated with long-term data, to inform the surgical workforce and ensure patient safety.

CLASSICA: Validating artificial intelligence in classifying cancer in real time during surgery

AIM

Treatment pathways for significant rectal polyps differ depending on the underlying pathology, but pre-excision profiling is imperfect. It has been demonstrated that differences in fluorescence perfusion signals following injection of indocyanine green (ICG) can be analysed mathematically and, with the assistance of artificial intelligence (AI), used to classify tumours endoscopically as benign or malignant. This study aims to validate this method of characterization across multiple clinical sites regarding its generalizability, usability and accuracy while developing clinical-grade software to enable it to become a useful method.

METHODS

The CLASSICA study is a prospective, unblinded multicentre European observational study aimed to validate the use of AI analysis of ICG fluorescence for intra-operative tissue characterization. Six hundred patients undergoing transanal endoscopic evaluation of significant rectal polyps and tumours will be enrolled in at least five clinical sites across the European Union over a 4-year period. Video recordings will be analysed regarding dynamic fluorescence patterns centrally as software is developed to enable analysis with automatic classification to happen locally. AI-based classification and subsequently guided intervention will be compared with the current standard of care including biopsies, final specimen pathology and patient outcomes.

DISCUSSION

CLASSICA will validate the use of AI in the analysis of ICG fluorescence for the purposes of classifying significant rectal polyps and tumours endoscopically. Follow-on studies will compare AI-guided targeted biopsy or, indeed, AI characterization alone with traditional biopsy and AI-guided local excision versus traditional excision with regard to marginal clearance and recurrence.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

Safe implementation of hand held steerable laparoscopic instruments: a survey among EAES surgeons

The complexity of handheld steerable laparoscopic instruments (SLI) may impair the learning curve compared to conventional instruments when first utilized. This study aimed to provide the current state of interest in the use of SLI, the current use of these in daily practice and the type of training which is conducted before using SLI in the operating room (OR) on real patients. An online survey was distributed by European Association of Endoscopic Surgery (EAES) Executive Office to all active members, between January 4th and February 3rd, 2020. The survey consisted of 14 questions regarding the usage and training of steerable laparoscopic instruments. A total of 83 members responded, coming from 33 different countries. Twenty three percent of the respondents using SLI, were using the instruments routinely and of these 21% had not received any formal training in advance of using the instruments in real patients. Of all responding EAES members, 41% considered the instruments to potentially compromise patient safety due to their complexity, learning curve and the inexperience of the surgeons. The respondents reported the three most important aspects of a possible steerable laparoscopic instruments training curriculum to be: hands-on training, safe tissue handling and suturing practice. Finally, a major part of the respondents consider force/pressure feedback data to be of significant importance for implementation of training and assessment of safe laparoscopic and robotic surgery. Training and assessment of skills regarding safe implementation of steerable laparoscopic instruments is lacking. The respondents stressed the need for specific hands-on training during which feedback and assessment of skills should be guaranteed before operating on real patients.

Could fluorescence-guided surgery be an efficient and sustainable option? A SICE (Italian Society of Endoscopic Surgery) health technology assessment summary

BACKGROUND

Indocyanine green fluorescence vision is an upcoming technology in surgery. It can be used in three ways: angiographic and biliary tree visualization and lymphatic spreading studies. The present paper shows the most outstanding results from an health technology assessment study design, conducted on fluorescence-guided compared with standard vision surgery.

METHODS

A health technology assessment approach was implemented to investigate the economic, social, ethical, and organizational implications related to the adoption of the innovative fluorescence-guided view, with a focus on minimally invasive approach. With the support of a multidisciplinary team, qualitative and quantitative data were collected, by means of literature evidence, validated questionnaires and self-reported interviews, considering the dimensions resulting from the EUnetHTA Core Model.

RESULTS

From a systematic search of literature, we retrieved the following studies: 6 on hepatic, 1 on pancreatic, 4 on biliary, 2 on bariatric, 4 on endocrine, 2 on thoracic, 11 on colorectal, 7 on urology, 11 on gynecology, 2 on gastric surgery. Fluorescence guide has shown advantages on the length of hospitalization particularly in colorectal surgery, with a reduction of the rate of leakages and re-do anastomoses, in spite of a slight increase in operating time, and is confirmed to be a safe, efficacious, and sustainable vision technology. Clinical applications are still presenting a low evidence in the literature.

CONCLUSION

The present paper, under the patronage of Italian Society of Endoscopic Surgery, based on an HTA approach, sustains the use of fluorescence-guided vision in minimally invasive surgery, in the fields of general, gynecologic, urologic, and thoracic surgery, as an efficient and economically sustainable technology.

Should enhanced recovery after surgery (ERAS) pathways be preferred over standard practice for patients undergoing abdominal wall reconstruction? A systematic review and meta-analysis

PURPOSE

Although many studies assessing enhanced recovery after surgery (ERAS) pathways in abdominal wall reconstruction (AWR) have recently demonstrated lower rates of postoperative morbidity and a decrease in postoperative length of stay compared to standard practice, the utility of ERAS in AWR remains largely unknown.

METHODS

A systematic literature search for randomized and non-randomized studies comparing ERAS (ERAS +) pathways and standard protocols (Control) as an adopted practice for patients undergoing AWR was performed using MEDLINE, the Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and EMBASE databases. A predefined search strategy was implemented. The included studies were reviewed for primary outcomes: overall postoperative morbidity, abdominal wall morbidity, surgical site infection (SSI), and length of hospital stay; and for secondary outcome: operative time, estimated blood loss, time to discontinuation of narcotics, time to urinary catheter removal, time to return to bowel function, time to return to regular diet, and readmission rate. Standardized mean difference (SMD) was calculated for continuous variables and Odds Ratio for dichotomous variables.

RESULTS

Five non-randomized studies were included for qualitative and quantitative synthesis. 840 patients were allocated to either ERAS + (382) or Control (458). ERAS + and Control groups showed equivalent results with regard to the incidence of postoperative morbidity (OR 0.73, 95% CI 0.32-1.63; I²= 76%), SSI (OR 1.17, 95% CI 0.43-3.22; I²= 54%), time to return to bowel function (SMD - 2.57, 95% CI - 5.32 to 0.17; I²= 99%), time to discontinuation of narcotics (SMD - 0.61, 95% CI - 1.81 to 0.59; I²= 97%), time to urinary catheter removal (SMD - 2.77, 95% CI - 6.05 to 0.51; I²= 99%), time to return to regular diet (SMD - 0.77, 95% CI - 2.29 to 0.74; I²= 98%), and readmission rate (OR 0.82, 95% CI 0.52-1.27; I²= 49%). Length of hospital stay was significantly shorter in the ERAS + compared to the Control group (SMD - 0.93, 95% CI - 1.84 to - 0.02; I²= 97%).

CONCLUSIONS

The introduction of an ERAS pathway into the clinical practice for patients undergoing AWR may cause a decreased length of hospitalization. These results should be interpreted with caution, due to the low level of evidence and the high heterogeneity.

Individual participant data pooled-analysis of risk factors for recurrence after neoadjuvant radiotherapy and transanal local excision of rectal cancer: the PARTTLE study

BACKGROUND

An organ-preserving strategy may be a valid alternative in the treatment of selected patients with rectal cancer after neoadjuvant radiotherapy. Preoperative assessment of the risk for tumor recurrence is a key component of surgical planning. The aim of the present study was to increase the current knowledge on the risk factors for tumor recurrence.

METHODS

The present study included individual participant data of published studies on rectal cancer surgery. The literature was reviewed according to according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Individual Participant Data checklist (PRISMA-IPD) guidelines. Series of patients, whose data were collected prospectively, having neoadjuvant radiotherapy followed by transanal local excision for rectal cancer were reviewed. Three independent series of univariate/multivariate binary logistic regression models were estimated for the risk of local, systemic and overall recurrence, respectively.

RESULTS

We identified 15 studies, and 7 centers provided individual data on 517 patients. The multivariate analysis showed higher local and overall recurrences for ypT3 stage (OR 4.79; 95% CI 2.25-10.16 and OR 6.43 95% CI 3.33-12.42), tumor size after radiotherapy > 10 mm (OR 5.86 95% CI 2.33-14.74 and OR 3.14 95% CI 1.68-5.87), and lack of combined chemotherapy (OR 3.68 95% CI 1.78-7.62 and OR 2.09 95% CI 1.10-3.97), while ypT3 was the only factor correlated with systemic recurrence (OR 5.93). The analysis of survival curves shows that the overall survival is associated with ypT and not with cT.

CONCLUSIONS

Local excision should be offered with caution after neoadjuvant chemoradiotherapy to selected patients with rectal cancers, who achieved a good response to neoadjuvant chemoradiotherapy.

Is the outpatient management of acute diverticulitis safe and effective? A systematic review and meta-analysis

BACKGROUND

In Western countries, the incidence of acute diverticulitis (AD) is increasing. Patients with uncomplicated diverticulitis can undergo a standard antibiotic treatment in an outpatient setting. The aim of this systematic review was to assess the safety and efficacy of the management of acute diverticulitis in an outpatient setting.

METHODS

A literature search was performed on PubMed, Scopus, Embase, Central and Web of Science up to September 2018. Studies including patients who had outpatient management of uncomplicated acute diverticulitis were considered. We manually checked the reference lists of all included studies to identify any additional studies. Primary outcome was the overall failure rates in the outpatient setting. The failure of outpatient setting was defined as any emergency hospital admission in patients who had outpatient treatment for AD in the previous 60 days. A subgroup analysis of failure was performed in patients with AD of the left colon, with or without comorbidities, with previous episodes of AD, in patients with diabetes, with different severity of AD (pericolic air and abdominal abscess), with or without antibiotic treatment, with ambulatory versus home care unit follow-up, with or without protocol and where outpatient management is a common practice. The secondary outcome was the rate of emergency surgical treatment or percutaneous drainage in patients who failed outpatient treatment.

RESULTS

This systematic review included 21 studies including 1781 patients who had outpatient management of AD  including 11 prospective, 9 retrospective and only 1 randomized trial. The meta-analysis showed that outpatient management is safe, and the overall failure rate in an outpatient setting was 4.3% (95% CI 2.6%-6.3%). Localization of diverticulitis is not a selection criterion for an outpatient strategy (p 0.512). The other subgroup analyses did not report any factors that influence the rate of failure: previous episodes of acute diverticulitis (p = 0.163), comorbidities (p = 0.187), pericolic air (p = 0.653), intra-abdominal abscess (p = 0.326), treatment according to a registered protocol (p = 0.078), type of follow-up (p = 0.700), type of antibiotic treatment (p = 0.647) or diabetes (p = 0.610). In patients who failed outpatient treatment, the majority had prolonged antibiotic therapy and only few had percutaneous drainage for an abscess (0.13%) or surgical intervention for perforation (0.06%). These results should be interpreted with some caution because of the low quality of available data.

CONCLUSIONS

The outpatient management of AD can reduce the rate of emergency hospitalizations. This setting is already part of the common clinical practice of many emergency departments, in which a standardized protocol is followed. The data reported suggest that this management is safe if associated with an accurate selection of patients (40%); but no subgroup analysis demonstrated significant differences between groups (such as comorbidities, previous episode, diabetes). The main limitations of the findings of the present review concern their applicability in common clinical practice as it was impossible to identify strict criteria of failure.

Multicentre international trial of laparoscopic lavage for Hinchey III acute diverticulitis (LLO Study)

BACKGROUND

Laparoscopic lavage was proposed in the 1990s to treat purulent peritonitis in patients with perforated acute diverticulitis. Prospective randomized trials had mixed results. The aim of this study was to determine the success rate of laparoscopic lavage in sepsis control and to identify a group of patients that could potentially benefit from this treatment.

METHODS

This retrospective multicentre international study included consecutive patients from 24 centres who underwent laparoscopic lavage from 2005 to 2015.

RESULTS

A total of 404 patients were included, 231 of whom had Hinchey III acute diverticulitis. Sepsis control was achieved in 172 patients (74·5 per cent), and was associated with lower Mannheim Peritonitis Index score and ASA grade, no evidence of free perforation, absence of extensive adhesiolysis and previous episodes of diverticulitis. The operation was immediately converted to open surgery in 19 patients. Among 212 patients who underwent laparoscopic lavage, the morbidity rate was 33·0 per cent; the reoperation rate was 13·7 per cent and the 30-day mortality rate 1·9 per cent. Twenty-one patients required readmission for early complications, of whom 11 underwent further surgery and one died. Of the 172 patients discharged uneventfully after laparoscopic lavage, a recurrent episode of acute diverticulitis was registered in 46 (26·7 per cent), at a mean of 11 (range 2-108) months. Relapse was associated with younger age, female sex and previous episodes of acute diverticulitis.

CONCLUSION

Laparoscopic lavage showed a high rate of successful sepsis control in selected patients with perforated Hinchey III acute diverticulitis affected by peritonitis, with low rates of operative mortality, reoperation and stoma formation.

Comparison of outcomes following intersphincteric resection vs low anterior resection for low rectal cancer: a systematic review

BACKGROUND

Low Rectal Anterior Resection (LAR) is challenging when anal canal mucosa and/or internal sphincter are involved by very low tumors. In these cases, Intersphincteric resection (ISR) with the removal of the internal sphincter is designed to increase the distal margin of resection, thus preserving the external sphincter and pubo-rectalis muscle complex. Aim is to compare results after ISR with those of LAR, including subgroup analysis of open, laparoscopic and robotic ISR.

METHODS

Studies published from January 1991 to January 2017 describing ISR and comparing results with LAR in adults were included irrespective of the technique. Tumor and surgical characteristics, clinical, functional and oncological results were collected.

RESULTS

25 non-randomized studies were included. Postoperative mortality ranged between 0% and 2.3%. The hospital stay ranged from 5 days to 40 days, lower in robotic ISR group if compared with laparoscopic ISR. Patients avoiding permanent stoma with ISR accept a lower continence level as satisfactory. Furthermore, anorectal function after ISR often tends to improve. ISR and LAR presented not statistically significant differences. Oncological outcomes were not statistically different Morbidity, blood loss and need for blood transfusions were lower in the laparoscopic ISR if compared with open approach.

CONCLUSIONS

Morbidity could more frequently affect open ISR if compared with laparoscopic ISR. Functional outcomes were influenced by neoadjuvant CRT, but not by the surgical approach of reconstruction, while were positively influenced by partial ISR with respect to total ISR.

Single-incision laparoscopic cholecystectomy is responsible for increased adverse events: results of a meta-analysis of randomized controlled trials

BACKGROUND

Over the last decade, single-incision laparoscopic cholecystectomy (SLC) has gained popularity, although it is not evident if benefits of this procedure overcome the potential increased risk. Aim of the study is to compare the outcome of SLC with conventional multi-incision laparoscopic cholecystectomy (MLC) in a meta-analysis of randomized controlled trials only.

METHODS

A systematic Medline, Embase, and Cochrane Central Register of Controlled Trials literature search of articles on SLC and MLC for any indication was performed in June 2017. The main outcomes measured were overall adverse events, pain score (VAS), cosmetic results, quality of life, and incisional hernias. Linear regression was used to model the effect of each procedure on the different outcomes.

RESULTS

Forty-six trials were included and data from 5141 participants were analysed; 2444 underwent SLC and 2697 MLC, respectively. Mortality reported was nil in both treatment groups. Overall adverse events were higher in the SLC group (RR 1.41; p < 0.001) compared to MLC group, as well severe adverse events (RR 2.06; p < 0.001) and even mild adverse events (RR 1.23; p = 0.041). This was confirmed also when only trials including 4-port techniques (RR 1.37, p = 0.004) or 3-port techniques were considered (RR 1.89, p = 0.020). The pain score showed a standardized mean difference (SMD) of - 0.36 (p < 0.001) in favour of SLC. Cosmetic outcome by time point scored a SMD of 1.49 (p < 0.001) in favour of SLC. Incisional hernias occurred more frequently (RR 2.97, p = 0.005) in the SLC group.

CONCLUSIONS

Despite SLC offers a better cosmetic outcome and reduction of pain, the consistent higher rate of adverse events, both severe and mild, together with the higher rate of incisional hernias, should suggest to reconsider the application of single incision techniques when performing cholecystectomy with the existing technology.

A systematic analysis of controlled clinical trials using the NiTi CAR™ compression ring in colorectal anastomoses

Anastomotic leak following colorectal surgery can be a devastating adverse event. The ideal stapling device should be capable of rapid creation of an anastomosis with serosal apposition without the persistence of a foreign body or a foreign body reaction which potentially contribute to early anastomotic dehiscence or late anastomotic stricture. A systematic review was performed examining available data on controlled randomized and non-randomized trials assessing the NiTi compression anastomosis ring-(NiTi CAR™) (NiTi Solutions, Netanyah Israel) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards. A protocol for this meta-analysis has been registered on PROSPERO (CRD42016050934). The initial search yielded 45 potentially relevant articles. After screening titles and abstracts for relevance and assessment for eligibility, 39 of these articles were eventually excluded leaving 6 studies for analysis in the review. Regarding the primary outcome measure, the overall anastomotic leak rate was 2.2% (5/230) in the compression anastomosis group compared with 3% (10/335) in the conventional anastomosis group; this difference was not statistically significant (RR 0.75, 95% CI 0.25-2.24; participants = 565; studies = 6; I ² = 0%). There were no statistically significant differences between compression and conventional anastomoses in any of the secondary outcomes. This review was unable to demonstrate any statistically significant differences in favor of the compression anastomosis technique over conventional manual or stapled mechanical anastomoses.

Transanal endoscopic microsurgery for giant circumferential rectal adenomas

AIM

Transanal endoscopic microsurgery (TEM) was originally invented by Buess et al. (Chirurg, 1984, 55, 677-80) for the treatment of infraperitoneal rectal adenomas. Its indications have progressively expanded to include larger and more advanced lesions. The aim of the study was to report the results of TEM used for the treatment of circumferential rectal lesions.

METHOD

We retrospectively reviewed the medical records of 17 consecutive patients [median age 69 (32-89) years; nine men] who underwent TEM for a circumferential rectal lesion in our department between September 2010 and January 2015.

RESULTS

The median distance from the anal verge was 4 (3-11) cm, the median longitudinal extent was 7 (3-10) cm and the median surface area was 75 (40-255) cm(2) . An end-to-end anastomosis without proximal bowel mobilization was completed endoscopically in all cases. The median operating time was 120 (40-240) min. Persistent, endoscopically uncontrollable endoluminal bleeding in one patient was successfully treated with a second TEM procedure. One patient underwent preoperative radiotherapy for adenocarcinoma detected at the preoperative assessment. Surgical histology showed a pT3 cancer in one patient who refused further surgery, a pT2 cancer in two who subsequently underwent abdominoperineal resection, a pT1 cancer in four and a ypT0 in one patient. All are at present free of disease. No patients developed faecal incontinence or urinary or sexual dysfunction. Four patients required endoscopic balloon dilatation for stenosis.

CONCLUSION

Transanal endoscopic microsurgery is a feasible and safe technique for large circumferential lesions with a satisfactory outcome. Preoperative staging may be inaccurate.

Frontiers of robotic endoscopic capsules: a review

Digestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd., is an example of disruptive technology and represents an attractive alternative to traditional diagnostic techniques. WCE overcomes conventional endoscopy enabling inspection of the digestive system without discomfort or the need for sedation. Thus, it has the advantage of encouraging patients to undergo gastrointestinal (GI) tract examinations and of facilitating mass screening programmes. With the integration of further capabilities based on microrobotics, e.g. active locomotion and embedded therapeutic modules, WCE could become the key-technology for GI diagnosis and treatment. This review presents a research update on WCE and describes the state-of-the-art of current endoscopic devices with a focus on research-oriented robotic capsule endoscopes enabled by microsystem technologies. The article also presents a visionary perspective on WCE potential for screening, diagnostic and therapeutic endoscopic procedures.

Transanal Endoscopic Operation under spinal anaesthesia

Background

Transanal Endoscopic Operation (TEO®) for rectal benign lesions and early rectal cancer may provide better oncological outcomes than flexible endoscopy. The major advantage of flexible endoscopy is that it does not require general anaesthesia. This prospective observational study assessed the feasibility and safety of TEO® performed under spinal anaesthesia.

Methods

The study population comprised eligible consecutive patients who underwent TEO® under spinal anaesthesia with curative or palliative intent for rectal neoplasms larger than 20 mm in diameter or for recurrent lesions of any size. The primary endpoints were feasibility and safety; secondary endpoints were postoperative pain, as measured on a visual analogue scale, heart rate, systolic and diastolic BP, opioid requested, postoperative nausea or vomiting, and urinary retention.

Results

The study included 50 patients (median age 70 years; 29 men and 21 women). No intraoperative complications occurred. The median duration of operation was 60 (range 20–165) min. No opioids were requested during the perioperative or postoperative period. The median postoperative pain score was 0 at 4, 8, 24 and 48 h after surgery. There were no significant fluctuations in heart rate, systolic and diastolic BP up to 48 h after the procedure (P = 0·379, P = 0·386 and P = 0·617 respectively). Postoperative nausea and vomiting occurred in one patient, and urinary retention in four.

Conclusion

TEO® under spinal anaesthesia was safe and feasible with no conversions to general anaesthesia.

Comfort and learnability assessment of a new soft robotic manipulator for minimally invasive surgery

Laparoscopic surgeons perform precise and time consuming procedures while holding awkward poses in their upper body and arms. There is an ongoing effort to produce robotic tools for laparoscopic surgery that will simplify these tasks and reduce risk of errors to help both the surgeon and the patient. STIFF-FLOP is an ongoing EU FP7 project focusing on this by creating a stiffness controllable soft robotic manipulator. This paper reports on a study to test the soft manipulator's learnability and the effort associated with its use. The tests involved a limited prototype of the manipulator with a custom built test rig and EMG acquisition system. Task times and video recordings along with EMG waveforms from the forearm muscles of participants (n=25) were measured for objective assessment. A questionnaire was also provided to the participants for subjective assessment. The data shows that in average EMG levels were 25.9% less in RMS when using the STIFF-FLOP arm than when conventional laparoscopic tools were used. In terms of learnability, from the first to the second attempt on the STIFF-FLOP manipulator, elapsed time was reduced by an average of 32.1%. Further details and analysis of the EMG signals as well as time and questionnaire results is presented in the paper.

Practice parameters for early rectal cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

The introduction of new technologies for diagnosis and screening programs led to an increasing rate of early detection of colorectal cancer. This, associated with the evolution of endoscopic techniques of local excision, led to the assessment of new strategies to reduce morbidity related to treatment, especially for early rectal cancer (ERC). Nevertheless, the definition of ERC and its staging and treatment algorithm are still under debate. The Italian Society of Colorectal Surgery developed practice guidelines to provide recommendations on the diagnosis, staging and treatment of ERC. A systematic review on the topic was performed by a multidisciplinary group of experts selected based on their clinical and scientific expertise in endoscopy, endoscopic ultrasound, magnetic resonance and surgery, with the aid of an external international audit.

Practice parameters for early colon cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

Early colon cancer (ECC) has been defined as a carcinoma with invasion limited to the submucosa regardless of lymph node status and according to the Royal College of Pathologists as TNM stage T1 NX M0. As the potential risk of lymph node metastasis ranges from 6 to 17% and the preoperative assessment of lymph node metastasis is not reliable, the management of ECC is still controversial, varying from endoscopic to radical resection. A meeting on recent advances on the management of colorectal polyps endorsed by the Italian Society of Colorectal Surgery (SICCR) took place in April 2014, in Genoa (Italy). Based on this material the SICCR decided to issue guidelines updating the evidence and to write a position statement paper in order to define the diagnostic and therapeutic strategy for ECC treatment in context of the Italian healthcare system.

NOTES in Europe: summary of the working group reports of the 2012 EURO-NOTES meeting

The sixth EURO-NOTES workshop (4 - 6 October 2012, Prague, Czech Republic) focused on enabling intensive scientific dialogue and interaction between surgeons, gastroenterologists, and engineers/industry representatives and discussion of the state of the practice and development of natural orifice transluminal endoscopic surgery (NOTES) in Europe. In accordance with previous meetings, five working groups were formed. In 2012, emphasis was put on specific indications for NOTES and interventional endoscopy. Each group was assigned an important indication related to ongoing research in NOTES and interventional endoscopy: cholecystectomy and appendectomy, therapy of colorectal diseases, therapy of adenocarcinoma and neoplasia in the upper gastrointestinal tract, treating obesity, and new therapeutic approaches for achalasia. This review summarizes consensus statements of the working groups.

Efficacy and safety of endoscopic submucosal dissection for colorectal neoplasia: a systematic review

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) has been proposed for large colorectal lesions, due to the high risk of recurrence following endoscopic mucosal resection. However, data on the efficacy and safety of colorectal ESD are still controversial. The aim of the current systematic review was to assess the efficacy and safety of colorectal ESD.

METHODS

A detailed Medline search of papers published during the period 1999-2010 was performed, using the search terms "Endoscopic submucosal dissection," "Colorectal neoplasia," "Colon," or "Rectum." Published studies that evaluated ESD for colorectal lesions were assessed using well-defined inclusion/exclusion criteria, including histological confirmation and surgery for complications. The process was independently performed by two authors. Forest plots on primary (i.e. histologically verified R0 resection and surgery for ESD complications) and secondary end-points were produced based on random-effect models. Heterogeneity was assessed using the I2 statistic. Risk for within-study bias was also ascertained.

RESULTS

A total of 22 studies (20 Asian, two European) provided data on 2841 ESD-treated lesions. The per-lesion summary estimate of R0 resection rate was 88% (95%CI 82%-92%; I2=91%). At meta-regression, carcinoid vs. non-carcinoid series (R0 93% vs. 87%; P=0.04) and Asian vs. European series (R0 88% vs. 65%; P=0.03) appeared to explain the detected heterogeneity. The per-lesion summary estimate of surgery for ESD complications was 1% (95%CI 0%-1%) with a moderate degree of heterogeneity (I2=49%). However, subgrouping of these results according to histological tumor types was not available in the reviewed studies.

CONCLUSIONS

ESD appeared to be an extremely effective technique to achieve R0 resection of large colorectal lesions. The very low rate of surgery for complications also shows the potential safety of this approach.

Magnetic air capsule robotic system: proof of concept of a novel approach for painless colonoscopy

BACKGROUND

Despite being considered the most effective method for colorectal cancer diagnosis, colonoscopy take-up as a mass-screening procedure is limited mainly due to invasiveness, patient discomfort, fear of pain, and the need for sedation. In an effort to mitigate some of the disadvantages associated with colonoscopy, this work provides a preliminary assessment of a novel endoscopic device consisting in a softly tethered capsule for painless colonoscopy under robotic magnetic steering.

METHODS

The proposed platform consists of the endoscopic device, a robotic unit, and a control box. In contrast to the traditional insertion method (i.e., pushing from behind), a "front-wheel" propulsion approach is proposed. A compliant tether connecting the device to an external box is used to provide insufflation, passing a flexible operative tool, enabling lens cleaning, and operating the vision module. To assess the diagnostic and treatment ability of the platform, 12 users were asked to find and remove artificially implanted beads as polyp surrogates in an ex vivo model. In vivo testing consisted of a qualitative study of the platform in pigs, focusing on active locomotion, diagnostic and therapeutic capabilities, safety, and usability.

RESULTS

The mean percentage of beads identified by each user during ex vivo trials was 85 ± 11%. All the identified beads were removed successfully using the polypectomy loop. The mean completion time for accomplishing the entire procedure was 678 ± 179 s. No immediate mucosal damage, acute complications such as perforation, or delayed adverse consequences were observed following application of the proposed method in vivo.

CONCLUSIONS

Use of the proposed platform in ex vivo and preliminary animal studies indicates that it is safe and operates effectively in a manner similar to a standard colonoscope. These studies served to demonstrate the platform's added advantages of reduced size, front-wheel drive strategy, and robotic control over locomotion and orientation.

Multicentre observational study of the natural history of left-sided acute diverticulitis

BACKGROUND

The natural history of acute diverticulitis (AD) is still unclear. This study investigated the recurrence rate, and the risks of emergency surgery, associated stoma and death following initial medical or surgical treatment of AD.

METHODS

The Italian Study Group on Complicated Diverticulosis conducted a 4-year multicentre retrospective and prospective database analysis of patients admitted to hospital for medical or surgical treatment of AD and then followed for a minimum of 9 years. The persistence of symptoms, recurrent episodes of AD, new hospital admissions, medical or surgical treatment, and their outcome were recorded during follow-up.

RESULTS

Of 1046 patients enrolled at 17 centres, 743 were eligible for the study (407 recruited retrospectively and 336 prospectively); 242 patients (32·6 per cent) underwent emergency surgery at accrual. After a mean follow-up of 10·7 years, rates of recurrence (17·2 versus 5·8 per cent; P < 0·001) and emergency surgery (6·9 versus 1·3 per cent; P = 0·021) were higher for medically treated patients than for those treated surgically. Among patients who had initial medical treatment, age less than 40 years and a history of at least three episodes of AD were associated with an increased risk of AD recurrence. There was no association between any of the investigated parameters and subsequent emergency surgery. The risk of stoma formation was below 1 per cent and disease-related mortality was zero in this group. The disease-related mortality rate was 0·6 per cent among patients who had surgical treatment.

CONCLUSION

Long-term risks of recurrent AD or emergency surgery were limited and colectomy did not fully protect against recurrence.

Natural orifice transluminal endoscopic surgery (NOTES) and colorectal cancer?

Surgical techniques and technologies are rapidly evolving. In the field of colorectal surgery the transanal video-assisted approach was introduced by Buess, 30 years ago, with transanal endoscopic microsurgery (TEM). In more recent years different techniques and technologies have been proposed, including natural orifice specimen extraction (NOSE), natural orifice transluminal endoscopic surgery (NOTES) and single-access surgery. Furthermore, a better understanding of the prognostic and risk factors of rectal cancer has allowed TEM to expand its indications to local resection of selected tumours, and more recently there have been proposals for sentinel node biopsy in colon and rectal cancer.

Enterovesical fistulas: diagnosis and management

Enterovesical fistula (EVF) is an abnormal communication between the intestine and the bladder. It represents a rare complication of inflammatory or neoplastic disease, and traumatic or iatrogenic injuries. The most common aetiologies are diverticular disease and colorectal carcinoma. Over 75% of affected patients describe pathognomonic features of pneumaturia, faecaluria and recurrent urinary tract infections. The diagnosis of EVF can be challenging, and frequently patients are monitored for months before the condition is recognised and treated effectively. Diagnostic tools include laboratory tests, imaging studies and endoscopic procedures. Although conservative management can be attempted in selected patients, in most cases, the treatment is mainly based on surgical interventions. Recently, the laparoscopic approach to EVF has been shown to be safe and effective. Although it is a rare condition in a general surgery setting, EVF is a challenging condition leading to high morbidity and mortality rates.

A magnetic internal mechanism for precise orientation of the camera in wireless endoluminal applications

BACKGROUND AND STUDY AIMS

The use of magnetic fields to control operative devices has been recently described in endoluminal and transluminal surgical applications. The exponential decrease of magnetic field strength with distance has major implications for precision of the remote control. We aimed to assess the feasibility and functionality of a novel wireless miniaturized mechanism, based on magnetic forces, for precise orientation of the camera.

MATERIALS AND METHODS

A remotely controllable endoscopic capsule was developed as proof of concept. Two intracapsular moveable permanent magnets allow fine positioning, and an externally applied magnetic field permits gross movement and stabilization. Performance was assessed in ex vivo and in vivo bench tests, using porcine upper and lower gastrointestinal tracts.

RESULTS

Fine control of capsule navigation and rotation was achieved in all tests with an external magnet held steadily about 15 cm from the capsule. The camera could be rotated in steps of 1.8 degrees . This was confirmed by ex vivo tests; the mechanism could adjust the capsule view at 40 different locations in a gastrointestinal tract phantom model. Full 360 degrees viewing was possible in the gastric cavity, while the maximal steering in the colon was 45 degrees in total. In vivo, a similar performance was verified, where the mechanism was successfully operated every 5 cm for 40 cm in the colon, visually sweeping from side to side of the lumen; 360 degrees views were obtained in the gastric fundus and body, while antrally the luminal walls prevented full rotation.

CONCLUSIONS

We report the feasibility and effectiveness of the combined use of external static magnetic fields and internal actuation to move small permanent intracapsular magnets to achieve wirelessly controllable and precise camera steering. The concept is applicable to capsule endoscopy as to other instrumentation for laparoscopic, endoluminal, or transluminal procedures.

Robotic versus manual control in magnetic steering of an endoscopic capsule

BACKGROUND AND STUDY AIMS

Capsular endoscopy holds promise for the improved inspection of the gastrointestinal tract. However, this technique is limited by a lack of controlled capsule locomotion. Magnetic steering has been proposed by the main worldwide suppliers of commercial capsular endoscopes and by several research groups. The present study evaluates and discusses how robotics may improve diagnostic outcomes compared with manual magnetic steering of an endoscopic capsule.

MATERIALS AND METHODS

An endoscopic capsule prototype incorporating permanent magnets was deployed in an ex vivo colon segment. An operator controlled the external driving magnet manually or with robotic assistance. The capsule was maneuvered through the colon, visualizing and contacting targets installed on the colon wall. Procedure completion time and number of targets reached were collected for each trial to quantitatively compare manual versus robotic magnetic steering ( T-test analysis with P = 0.01). Then, through a set of in vivo animal trials, the efficacy of both approaches was qualitatively assessed.

RESULTS

In ex vivo conditions, robotic-assisted control was superior to manual control in terms of targets reached (87 % +/- 13 % vs 37 % +/- 14 %). Manual steering demonstrated faster trial completion time (201 +/- 24 seconds vs 423 +/- 48 seconds). Under in vivo conditions, the robotic approach confirmed higher precision of movement and better reliability compared with manual control.

CONCLUSIONS

Robotic control for magnetic steering of a capsular endoscope was demonstrated to be more precise and reliable than manual operation. Validation of the proposed robotic system paves the way for automation of capsular endoscopy and advanced endoscopic techniques.

Laparoscopic-assisted transgastric cholecystectomy and secure endoscopic closure of the transgastric defect in a survival porcine model

BACKGROUND AND STUDY AIMS

Natural orifice transluminal endoscopic surgery holds promise for surgical interventions. Before the feasibility of this technique can be established, however, secure sealing of the transluminal access needs to be thoroughly investigated.

PATIENTS AND METHODS

Following antibiotic prophylaxis and gastric disinfection, nine pigs underwent transgastric cholecystectomy by means of a flexible endoscope with the aid of a transabdominal 5-mm trocar. The gastric wall was punctured and dilated. The gallbladder was retracted with a laparoscopic grasper. The cystic duct and artery were dissected with a flexible monopolar ball electrode. The cystic duct was interrupted with flexible scissors between endoclips. Cholecystectomy was completed and the gallbladder was retrieved through the stomach. The gastric defect was closed using a single modified over-the-scope clip (OTSC) (Ovesco, Tübingen, Germany) and grasping the serosal and muscle layer of the gastric wall. The animals were sacrificed 4 weeks later.

RESULTS

Laparoscopic-assisted transgastric cholecystectomy was successful in all cases without significant perioperative complications. All animals survived without postoperative complications. The mean operating time was 128 minutes (range, 85 - 205 minutes). The gastric defect closure resulted in inversion of the gastric wall layers within an average time of 6.8 +/- 5 minutes. At 4 weeks postoperative, only minimal thin adhesions were observed in the right hypochondrium.

CONCLUSIONS

We found gastric closure using the OTSC to be a reliable tool for closing the transgastric access. Laparoscopic-assisted transgastric cholecystectomy by means of a flexible endoscope was technically feasible, but remains a demanding procedure.

Clinical experience with a new endoscopic over-the-scope clip system for use in the GI tract

BACKGROUND

The newly designed over-the-scope clip (OTSC) seems to overcome several limitations of current clipping system, such as size and opening-closing force, allowing better control of gastric or colonic bleeding and/or deep wall defect or perforation.

AIMS

The aim of this retrospective analysis was to describe the new endoscopic device and evaluate our first clinical experience.

PATIENTS AND METHODS

We treated with the OTSC system 9 patients (range, 58-85 years; 6 men, 3 women) with bleeding and/or deep wall lesions of the GI tract. The OTSC system is composed of an application cap, which is mounted onto the distal tip of the endoscope and a connected releasing mechanism, installed on the handle of the scope. The rotation of the handle allows the release of the clip by a two tube sliding mechanism.

RESULTS

All applications resulted successful, i.e. haemostasis was achieved, and/or wall defects could be closed. No complication was observed that could be ascribed to the clip itself or to the technique.

CONCLUSIONS

The OTSC system is a new endoscopic tool for compression of large tissue areas and its indications are nonvaricose bleedings difficult to control and lesions or perforations of the GI tract. The initial clinical use of this clipping device proved to be efficient and effective.

Combined endoscopic treatment for cholelithiasis associated with choledocholithiasis

BACKGROUND

The advent of endoscopic techniques changed surgery in many ways. For the management of cholelithiasis, laparoscopic cholecystectomy (LC) is the treatment of choice. This has created a dilemma in the management of choledocholithiasis. Today a number of option exist, including endoscopic sphinterotomy (ES) before LC in patients with suspected common bile duct (CBD) stones, laparoscopic bile duct exploration, open CBD exploration, and postoperative endoscopic retrograde cholangiopancreatography (ERCP). Also, the alternative technique of peroperative ES is emerging.

METHODS

We report our experience of routine intraoperative cholangiography followed either by peroperative ERCP in one step or by transcystic drain and postoperative ERCP. In our technique, to facilitate Vater papilla cannulation we inserted a 450-cm transcystic guidewire that was caught by a duodenoscope. Papillotome was then inserted over the guidewire to ensure cannulation of the CBD.

RESULTS

Twenty-eight patients were treated successfully in one step and 24 in two steps. The mean operative time was 181 +/- 41 min for patients treated in one step and 131 +/- 30 min for patients treated in two steps. The mean hospital stay was 4.8 +/- 3.3 days for patients treated in one step and 9.6 +/- 4.0 days for patients treated in two steps. Five patients (18%) with positive intraoperative cholangiography for stones for whom peroperative ERCP was not available showed a normal postoperative transcystic cholangiogram and therefore ERCP was canceled. Fourteen of 25 patients treated in one step and none of 17 treated in two steps had raised serum amylase, which resolved spontaneously with no symptoms. No patient developed postoperative pancreatitis. Three (10%) ERCP complications were observed, consisting of mild bleeding of the papilla. All cases were managed by endoscopic adrenaline injection. There was no mortality.

CONCLUSION

We believe peroperative ERCP with the technique described should be considered as the treatment of choice for choledocholithiasis associated with cholelithiasis. When single-stage treatment is not possible, a two-step rendezvous technique should be preferred.

Experimental assessment of a new mechanical endoscopic solosurgery system: Endofreeze

BACKGROUND

The assistance received by the surgeon from support personnel during operative laparoscopy is extremely important. This includes retraction of instruments and endoscope positioning. However, human assistance is costly and often does not provide satisfaction for the surgeon. The aim of this study was to develop a mechanical arm capable of allowing easy handling and holding of laparoscopic instruments under the surgeon's control.

METHODS

We designed a system, named Endofreeze, based on a particular kinematical construction that maintains an invariant point of constraint motion just above the trocar puncture site through the abdominal wall. The goal was to develop this way a highly intuitive mechanical holding system for laparoscopic instruments, with sufficient precision of action, activated by a single hand movement. We tested a couple of prototypes with different holding arms while performing cholecystectomy in phantom models with swine inserts and compared the results obtained in similar conditions using different holding and positioning systems.

RESULTS

The system allows transparent and intuitive operation, and its setup is easy and quick. It may be adapted either as an instrument retractor or as an optic positioning device. Compared to different systems available or prototypes previously tested, such as AESOP 2000, ENDOASSIST, FIPS Endoarm, TISKA Endoarm, and the Martin Arm, in similar conditions, it was more intuitive, allowing shorter time for completion of surgery.

CONCLUSION

Endofreeze is a new intuitive mechanical positioning system for endoscopic solo surgery. In phantom models, it demonstrated a shorter time requirement for completion of surgery when compared to other systems available. In our opinion, it represents a valid compromise between human and robotic control for conventional laparoscopic instruments.

[Robotic and systems technology for advanced endoscopic procedures]

The advent of endoscopic techniques changed surgery in many regards. This paper intends to describe an overview about technologies to facilitate endoscopic surgery. The systems described have been developed for the use in general surgery, but an easy application also in other fields of endoscopic surgery seems realistic. The introduction of system technology and robotic technology enables today to design a highly ergonomic solo-surgery platform. This consists of a system of devices for endoscopic surgery (HF, light source, etc...) with which the surgeon interacts directly, positioning systems for optic and instruments that the surgeon drives as the likes without assistance, and a chair to increase the comfort of the surgeon during surgery. The system of endoscopic devices named OREST (Dornier, München) designed already in 1992 opened the way to a number of systems available today that allow to the surgeon a direct control of the instrumentation. A considerable step ahead in endoscopic technology is the introduction of robotic technology to design assisting systems for solo-surgery and microsurgical instrument manipulators. Results of a number of experimental trials on combinations of different positioning devices are presented and commented. A further step in the employment of robotic technology is the design of "master-slave manipulators" to provide the surgeon with additional degrees of freedom of instrumentation. In 1996 a first prototype of an endoscopic manipulator system, named ARTEMIS, designed in cooperation with the Research Center in Karlsruhe, could be used in experimental applications. Clinical use of the system, however, will require further development of the arm mechanics and the control system. The combination with the implementation of telecommunication technology will open new frontiers, such as teleconsulting, teleassistance and telemanipulation.

Experimental trial on solo surgery for minimally invasive therapy: comparison of different systems in a phantom model

BACKGROUND

Robotic aid in minimally invasive surgery (MIS) is becoming more and more common. We designed an experimental trial in a phantom model to verify the feasibility of solo surgery for MIS. By performing laparoscopic cholecystectomy on a phantom model, we compared combinations of different systems available in terms of safety, comfort, and time requirements.

METHODS

Two surgeons skilled in endoscopic procedures tested the following systems as endoscope holders: the robotic system (AESOP), foot-controlled (AESOP 1000), and voice-controlled (AESOP 2000); the remote controlled FIPS Endoarm, electrically driven and controlled by a finger-ring joystic; the passive system TISKA Endoarm, a mechanical arm moved by hand and fixed by electromagnetical brakes. All of these systems combined with a second TISKA Endoarm as an instrument holder. A combination of two mechanical Martin arms, c, also was tested. The results were compared with those from a control group involving an assistant surgeon. A total of 70 experiments were performed.

RESULTS

The shortest dissection time was registered by the combination of two TISKA Endoarms, with a statistically significant difference as compared with the control group (p < 0.05) and experiments using AESOP 1000 (p < 0.05). The TISKA Endoarm also proved to be more comfortable when used as an instrument holder (p < 0.001 vs Martin arm), and rated second only to AESOP 2000 as an endoscope holder. The rating of AESOP 2000 as endoscope holder was significantly higher than that of all other groups (p < 0.001). The study proved the feasibility of solo surgery. The time needed for dissection was shortest when two TISKA Endoarms were used, demonstrating the possible advantages of solo surgery. The TISKA Endoarm received a subjective positive rating when used as both endoscope holder and instrument holder. The voice control of AESOP 2000 seemed to be a major improvement in the development of an optimal man-machine interface. Nevertheless, the system presents considerable space requirements and does not supply control of 30 degrees optics. The principle of the finger-ring joystick adopted by the FIPS Endoarm seemed very intuitive but lacking in ergonomy.

CONCLUSION

Laparoscopic solo surgery can be considered a safe procedure, although further technologic developments should lead to improved ergonomy, intuitiveness of handling, and architecture of the systems, offering the surgeon better control, increased precision of action, and reduction in operation time.

[Positioning systems for endoscopic solo surgery]

BACKGROUND

Endoscopic surgery has acquired undisputed importance in the field of both general and specialised surgery. The introduction of robotic technology in surgery has recently led to the development of new positioning systems for endoscopic surgery. These allow direct control of the endoscopic procedures by the surgeon, whose vision currently depends on the assistant in charge of positioning the optic camera in compliance with his wishes.

METHODS

We experimented different positioning systems for optics and rigid endoscopic instruments for laparoscopy, some of which were our own design. Over 400 cholecystectomies were carried out by six different surgeons on phantoms containing animal organs. The experimental systems were AESOP (Computer Motion, USA), with both foot-pedal and voice control, ENDOASSIST (Armstrong Healthcare Co. UK), controlled by a device worn by the surgeon, FIPS Endoarm (Karlsruhe Research Centre, Germany), controlled by a joystick and voice, and the passive TISKA Endoarm system (Karlsruhe Research Centre, Germany). Combinations of two systems were compared, using one to position the optic and one to position the retractor instrument.

RESULTS

Phantom tests, which are preferable owing to constant conditions, showed the feasibility of experiments in Solo Surgery conditions and highlighted the advantages and drawbacks of the various systems. In particular, the surgeons appreciated the intuitive use of the TISKA Endoarm system as a positioner for the retractor instrument and the optics, in spite of the fact that it was only a passive movement apparatus. Among the remote-control systems tested as an optics positioner, FIPS Endoarm controlled by a joystick was particularly intuitive and produced the best results in terms of time taken to complete the procedure. The time taken was even shorter than that in a large control group with human assistance.

CONCLUSIONS

In our experience endoscopic Solo Surgery was found to be applicable to clinical practice. This will bring numerous advantages in terms of the precision of surgical procedures and savings in terms of time and human resources, with a consequent reduction of management costs. There is no doubt that this method represents a step forward in the application of technology to surgery.

Prospective randomized trial comparing bowel cleaning preparations for colonoscopy

Colonoscopy is commonly accepted as the procedure of choice for the detection and treatment of colonic lesions. The current study was undertaken to compare effectiveness and tolerance of different bowel preparations. Three hundred patients were randomized into three groups, to be administered either a senna compound, a polyethylene glycol lavage, or an oral sodium phosphate (NaP) solution. Tolerance of the preparation was considered. After each colonoscopy, the endoscopist blindly scored cleansing for each bowel segment and defined the quality of the examination as "optimal," "acceptable," or to be repeated. Significantly more patients in Group C (68%) achieved a "good" cleansing compared with Group B (50%; P < 0.0001) and with Group A (38%; P < 0.005). Sixty-three percent of constipated patients obtained a "good" preparation in Group C, which was significantly higher than in Group A (28%; P < 0.05) and than in Group B (42%; P < 0.02). Feasibility of the examination was considered "optimal" in 80% of procedures in Group C, which was higher than in Group A (59%; P < 0.005) and in Group B (62%; P < 0.005). The tolerance of preparation was "good" in 93% of the examinations for Group C. This prospective randomized trial showed good effectiveness of NaP solutions, with an optimal tolerance. Results of use of the NaP solution showed a clear advantage for constipated patients, with similar results for nonconstipated patients. The author believes that the NaP solution should be the standard preparation for elective colonoscopy.

[Shadow optic. An endoscope with optimized ligth]

Modern endoscopes use a single mid-frontal illumination source that yields an unnatural flat image. At the University of Tübingen, in collaboration with Gimmi GmbH (Tuttlingen, Germany), a new concept endoscope has been developed with an additional light source: the shadow optic. With the aid of a secondary light source along the axis of the endoscope, a shadow is obtained which gives an impression of spatial depth. The aim of the study was to assess this new endoscope objectively, focusing on the speed and safety of the surgical act. The shadow optic was used in an experimental setting by 20 probands, each of whom performed five different standardized procedures of increasing difficulty five times, with and without shadow optic in randomized sequence, making a total of 1000 experiments. The procedures consisted in spatial orientation tests, structure-surrounding maneuvers, tissue clamping, needle puncture and suturing. The evaluation criteria were the time required to perform the procedures and the number of predefined errors as determined by electronic control. In each procedure, the time needed to perform the experiments was shorter with the shadow optic, reductions of up to 18% being recorded, and the number of errors was up to 54% lower compared to the experiments conducted with the traditional endoscope. The results of the study demonstrate that, as a result of the more natural spatial view conditions, the procedures were performed faster and with greater precision when the shadow optic was used. The endoscopic imaging with the shadow optic makes for better spatial orientation and a more natural and manageable image.

A new remote-controlled endoscope positioning system for endoscopic solo surgery. The FIPS endoarm

In the field of endoscopic solo surgery, the assistance received by the surgeon from ergonomical positioning devices is extremely important. They aid in both the retracting of instruments and the positioning of the endoscope. However, passive systems derived from open surgery have not proved satisfactory. Therefore, we set out to develop a remote-controlled arm capable of moving a rigid endoscope with about four degrees of freedom, while maintaining an invariant point of constraint motion coincident with the trocar puncture site through the abdominal wall. The system is driven by means of speaker-independent voice control or a finger-ring joystick clipped onto the instrument shaft close to the handle. When the joystick is used, the motion of the endoscope is controlled by the fingertip of the operating surgeon, which is inserted into the small ring of the controller in such a way as to make the motion of the fingertip correspond directly to the motion of the tip of the endoscope. A study was performed to compare the two different interfaces available for the system. With both interfaces, the guiding system allows for transparent and intuitive operation. Its set-up is easy; it is safe and reliable to use during the intervention; and it is faster than human assistance. With its improved ergonomy, this new generation of remote-controlled endoscope positioning system represents a further step toward the diffusion of solo surgery techniques in minimally invasive therapy. In our opinion, this prototype creates a valid compromise between human and robotic control of rigid endoscopes.

Robotics and systems technology for advanced endoscopic procedures: experiences in general surgery

The advent of endoscopic techniques changed surgery in many regards. This paper intends to describe an overview about technologies to facilitate endoscopic surgery. The systems described have been developed for the use in general surgery, but an easy application also in the field of cardiac surgery seems realistic. The introduction of system technology and robotic technology enables today to design a highly ergonomic solo-surgery platform. To relief the surgeon from fatigue we developed a new chair dedicated to the functional needs of endoscopic surgery. The foot pedals for high frequency, suction and irrigation are integrated into the basis of the chair. The chair is driven by electric motors controlled with an additional foot pedal joystick to achieve the desired position in the OR. A major enhancement for endoscopic technology is the introduction of robotic technology to design assisting devices for solo-surgery and manipulators for microsurgical instrumentation. A further step in the employment of robotic technology is the design of 'master-slave manipulators' to provide the surgeon with additional degrees of freedom of instrumentation. In 1996 a first prototype of an endoscopic manipulator system. named ARTEMIS, could be used in experimental applications. The system consists of a user station (master) and an instrument station (slave). The surgeon sits at a console which integrates endoscopic monitors, communication facilities and two master devices to control the two slave arms which are mounted to the operating table. Clinical use of the system, however, will require further development in the area of slave mechanics and the control system. Finally the implementation of telecommunication technology in combination with robotic instruments will open new frontiers, such as teleconsulting, teleassistance and telemanipulation.

The role and future of endoscopic imaging systems

Visual perception is the main sensory input from the environment in most situations of daily life. It is the only sensory input from the operating field in endoscopic surgery, and thus the qualities of the optical imaging system have a considerable impact on the course of the surgical intervention. Significant improvements have been made recently in various fields of science and engineering, influencing endoscopic imaging systems in experimental and clinical use. Among these are technologies that improve the endoscope itself in terms of providing new visual features, such as fogging prevention and plastic images, using new illumination techniques. Other developments concern the improvement of image resolution and color fidelity through new charge-coupled device (CCD) sensors or alternative techniques for image creation. Finally, the combination of endoscopic technologies with robotics provides for intuitive and more efficient direction of the line of sight.

Trocar and instrument positioning system TISKA. An assist device for endoscopic solo surgery

The assistance received by the surgeon from support personnel during surgical laparoscopy is extremely important. This includes the retracting of instruments and the positioning of the endoscope. However, human assistance is costly and often does not provide satisfaction for the surgeon. The aim of the project was to develop a mechanical arm capable of manipulating a laparoscopic instrument under the control of the operating surgeon. The system design is based on a particular kinematic construction that maintains an invariant point of constraint motion coincident with the trocar puncture site through the abdominal wall. The guidance system allows transparent and intuitive operation, and its setup is easy and quick. It may be adapted either as an instrument retractor or as an optic positioning device. A new generation of instrument positioning systems, with improved ergonomy, will be a first step toward the diffusion of solo surgery techniques in minimally invasive therapy. We believe this prototype represents a valid compromise between human and robotic control for conventional laparoscopic instruments.