Minimally invasive single-site surgery for the digestive system: A technological review

An improved camera model for oblique-viewing laparoscopes: high reprojection accuracy independent of telescope rotation

Objective. Oblique-viewing laparoscopes are popular in laparoscopic surgeries where the target anatomy is located in narrow areas. Their viewing direction can be shifted by telescope rotation without changing the laparoscope pose. This rotation also changes laparoscope camera parameters that are estimated by camera calibration to be able to reproject an anatomical model onto the laparoscopic view, creating augmented reality (AR). The aim of this study was to develop a camera model that accounts for these changes, achieving high reprojection accuracy for any telescope rotation.Approach. Camera parameters were acquired by calibrations encompassing a wide telescope rotation range. For those parameters showing periodic changes upon rotation, interpolation models were created and used to establish an updatable camera model. With this model, corner points of a tracked checkerboard were reprojected onto the checkerboard laparoscopic images, at random rotation angles. Root-mean-square reprojection errors (RMSEs) were calculated between the reprojected and imaged corner points.Main results. Reprojection RMSEs were low and approximately independent on telescope rotation angle, over a wide rotation range of 320°. The mean reprojection RMSE was 2.8±0.7 pixels for a conventional laparoscope and 3.6±0.7 pixels for a chip-on-the-tip (COTT) laparoscope, corresponding to 0.3±0.1 mm and 0.4±0.1 mm in world coordinates respectively. Worst-case reprojection errors were about 9 pixels (0.8 mm) for both laparoscopes.Significance. The camera model developed in this study improves on existing models for oblique-viewing laparoscopes because it provides high reprojection accuracy independent of the telescope rotation angle and is applicable for conventional and chip-on-a-tip oblique-viewing laparoscopes. The work presented here is an important step towards creating accurate AR in image-guided interventions where oblique-viewing laparoscopes are used while simultaneously providing the surgeon the flexibility to rotate the telescope to any desired rotation angle.Acronyms. CC: camera coordinates; CCToolbox: camera calibration toolbox; COTT: chip-on-the-tip; CS: camera sensor; DD: decentering distortion; FL: focal length; OTS: optical tracking system; PP: principal point; RD: radial distortion; SI: supplementary information;tHE:hand-eye translation component.

Motion Measurement and Analysis of Different Instruments for Single-Incision Laparoscopic Surgery

Objective

To objectively compare and analyze the range of motion of three types of instruments for single-incision laparoscopic surgery. Material and Methods. Ten experienced participants were recruited. Straight instruments (Group A), straight/articulating instruments (Group B), and precurved instruments (Group C) were used to complete the transferring task through one site in a laparoscopic simulator. Straight instruments via two separate sites (Group D) served as control. The operation time of each group was recorded. Instrument positions were measured by an optical tracking system. The inserted length and pivoting angles were derived via MATLAB.

Results

There was a significant difference in operation time between groups (D < A < B < C, p < 0.01). The range of motion of instruments was different on instrument types and surgical approaches. A significant difference in the inserted length was found between groups. Instrument conflicts and inadequate triangulation were found in Group A; instrument conflicts were found in Group B; no obvious conflicts and triangulation problems were observed in Group C. The operation in Group C was similar to the operation in Group D but differed on the left/right pivoting angles.

Conclusion

Different types of instruments have different ranges of motion in single-incision laparoscopic surgery. Working with precurved instruments seems like a compromise to traditional laparoscopic surgery if the transmission property, and shaft curvature of the instruments could be improved. An integrated mechanical platform or robotic system might be the ultimate solution for single-incision laparoscopic surgery to pursue even less trauma.

Short-term clinical and oncological outcomes after single-incision plus one-port laparoscopic surgery for rectosigmoid cancer: a retrospective clinical analysis of 30 cases

Objective

To evaluate the safety and feasibility of single-incision laparoscopic surgery+1 (SILS+1) radical resection of sigmoid and upper rectal cancer.

Methods

The clinical data of 30 consecutive patients with sigmoid and upper rectal cancer who underwent SILS+1 radical resection between October 2018 and January 2020 in our hospital were retrospectively analyzed. An initial 5-cm periumbilical transverse incision was made. Then, a multiport device was placed in the umbilical incision. Two 10-mm ports were used for laparoscope insertion, and the other two ports were used for laparoscope device insertion. A 12-mm trocar was placed in the right lower abdominal quadrant under laparoscopic view and served as the surgeon’s dominant operating channel.

Results

All operations were performed successfully without conversion to conventional laparoscopic surgery or open operation. Three patients developed postoperative complications: one patient developed ileus, one developed postoperative bleeding, and one developed wound infection. There were no perioperative deaths.

Conclusions

The safety and feasibility of SILS+1 radical resection of sigmoid and upper rectal cancer was established by experienced surgeons in our study. However, further studies are needed to demonstrate the advantages of this procedure compared with the benefits of conventional laparoscopic surgery.

A gesture-based design tool: Assessing 2DOF vs. 4DOF steerable instrument control

Iterative prototyping is costly and time-consuming. Particularly when designing medical instruments, human factors related design choices significantly impact performance and safety. A tool is presented that allows for the evaluation of steerable instrument controls before the onset of the prototyping stage. The design tool couples gestural input to virtually simulated instrument motions using hand motion tracking. We performed a human-subject evaluation of two manual control strategies that differed in their degrees of freedom (DOF). 2DOF thumb control was compared to 4DOF thumb-index finger control. Results identified regions within the instrument workspace that are difficult to reach and showed participants to favor using the thumb for gross and fine-tuning motions at both control strategies. Index finger ab/adduction was found to be least functional. A strong learning effect was observed at 4DOF control. Based on the results, gesture-based instrument design is a viable design tool.

Compact teleoperated laparoendoscopic single-site robotic surgical system: Kinematics, control, and operation

BACKGROUND

To date a variety of teleoperated surgical robotic systems have been developed to improve a surgeon's ability to perform demanding single-port procedures. However typical large systems are bulky, expensive, and afford limited angular motion, while smaller designs suffer complications arising from limited motion range, speed, and force generation. This work was to develop and validate a simple, compact, low cost single site teleoperated laparoendoscopic surgical robotic system, with demonstrated capability to carry out basic surgical procedures.

METHODS

This system builds upon previous work done at the University of Hawaii at Manoa and includes instrument and endoscope manipulators as well as compact articulated instruments designed to overcome single incision geometry complications. A robotic endoscope holder was used for the base, with an added support frame for teleoperated manipulators and instruments fabricated mostly from 3D printed parts. Kinematics and control methods were formulated for the novel manipulator configuration.

RESULTS

Trajectory following results from an optical motion tracker and sample task performance results are presented.

CONCLUSIONS

Results indicate that the system has successfully met the goal of basic surgical functionality while minimizing physical size, complexity, and cost.

Single-incision laparoscopic ileocecal resection using an organ retractor

INTRODUCTION

Single-incision laparoscopic surgery has been reported to be a safe and feasible technique for colorectal cancer. However, the technique needs skill due to the limitations of the device. An organ retractor is a new grasp device that has the potential to overcome these limitations.

PRESENTATION OF CASE

A 63-year-old woman with a tumor palpated in the right lower quadrant of the abdomen presented to hospital. Colonoscopy showed a type 2 mass with nearly complete stenosis, and a biopsy specimen showed well-differentiated adenocarcinoma. Single-incision laparoscopic surgery ileocecal resection was performed using an organ retractor. A 3-cm incision was placed in the umbilicus, and three conventional ports were inserted. An organ retractor was used for hepatocolic ligament resection, resection of the ileocolic vessels, and resection of the insertion of the mesentery proper. For each resection, the trailer line's tension was adjusted to provide a good operative view. The patient's postoperative course was good, and she was discharged 7days after surgery.

DISCUSSION

An organ retractor was effective for single-incision laparoscopic surgery technique not only to maintain a good operative view, but also to change trailer line tension, which enabled safe dissection.

CONCLUSION

An organ retractor could facilitate single-incision laparoscopic surgery.

Efficacy and safety of a new single-port model for appendectomy: Experimental study on swine

CONTEXT:

With the cooperation of surgeons and the engineering division of the company Bhio supply^© (Esteio-RS, Brazil), a permanent single port was developed.

AIMS:

An experimental study assessed the safety and efficacy of the device using a swine laparoscopic appendectomy model (right salpingo-oophorectomy).

SETTINGS AND DESIGN:

Experimental randomised study.

MATERIALS AND METHODS:

A total of 20 pigs were randomised for the conventional laparoscopic (CL) three-trocar technique or the single Centry port (CPort) with two working channels, aided by a transparietal thread. Operative times, surgical complications, CO₂ use, and pneumoperitoneal pressure were checked. Pressure and chromopertubation tests assessed the ligatures.

STATISTICAL ANALYSIS USED:

For quantitative outcomes, the Fisher's exact test analysed the samples to compare the surgeons in each group, the ANOVA test for parametric data (volume and pressure) and the Student's t-test for analysis of the fascial incision length. The binaries and isolated occurrence events were described in percentages.

RESULTS:

For all cases, pneumoperitoneum was maintained. The CPort group, however, resulted in higher CO₂ use (26.18 l; standard deviation [SD] ± 11.09) than CL group (5.69 l; SD ± 2.44) (P < 0.01). The mean pressure in CPort group (6.604 mmHg, SD ± 1.793) was comparatively lower than in CL group (7.382 mmHg, SD ± 1.833) (P = 0.363). There was no statistical difference between operative times, ligature safety or adverse surgical events between the different groups and surgeons.

CONCLUSION:

The surgical technique used with the single port showed no differences in safety and efficacy. Though it does require more CO₂ use, its working dynamics did not lead to increased operative times. The results were similar between the two surgeons in the study, suggesting that they can be reproduced.

Laparoscopic colorectal surgery: Current status and implementation of the latest technological innovations

The introduction of laparoscopy is an example of surgical innovation with a rapid implementation in many areas of surgery. A large number of controlled studies and meta-analyses have shown that laparoscopic colorectal surgery is associated with the same benefits than other minimally invasive procedures, including lesser pain, earlier recovery of bowel transit and shorter hospital stay. On the other hand, despite initial concerns about oncological safety, well-designed prospective randomized multicentre trials have demonstrated that oncological outcomes of laparoscopy and open surgery are similar. Although the use of laparoscopy in colorectal surgery has increased in recent years, the percentages of patients treated with surgery using minimally invasive techniques are still reduced and there are also substantial differences among centres. It has been argued that the limiting factor for the use of laparoscopic procedures is the number of surgeons with adequate skills to perform a laparoscopic colectomy rather than the tumour of patients’ characteristics. In this regard, future efforts to increase the use of laparoscopic techniques in colorectal surgery will necessarily require more efforts in teaching surgeons. We here present a review of recent controversies of the use of laparoscopy in colorectal surgery, such as in rectal cancer operations, the possibility of reproducing complete mesocolon excision, and the benefits of intra-corporeal anastomosis after right hemicolectomy. We also describe the results of latest innovations such as single incision laparoscopic surgery, robotic surgery and natural orifice transluminal endoscopic surgery for colon and rectal diseases.

The quest for precision in transanal total mesorectal excision

Transanal total mesorectal excision (TME) is an emerging minimally invasive approach to rectal cancer, with encouraging preliminary results. However, the new surgical anatomy of the bottom-up approach complicates surgical understanding and increases the risks of inadvertent injuries to crucial anatomical structures, including nerves. Key elements to improve the safety and stimulate interest in such a complex technique might be robotics and image guidance, to enhance the level of precision. In this editorial, some of the technologies that could be used for precision TME are outlined, in light of the experience of our Institute for Image-Guided Surgery.

SILS v SILS+1: a Case-Matched Comparison for Colorectal Surgery

BACKGROUND

Single-incision laparoscopic surgery (SILS) is safe and feasible for benign and malignant colorectal diseases. SILS has comparable or improved outcomes compared to multiport laparoscopy but technical limitations when operating in the pelvis. To address these limitations, we developed an innovative SILS+1 approach using a single Pfannenstiel incision for pelvis access with one additional umbilical port. Our goal was to compare outcomes for SILS and SILS+1 in lower abdominal and pelvic colorectal surgery.

METHODS

Review of a prospectively maintained database identified patients who underwent an elective reduced port laparoscopic lower abdominal/pelvic colorectal procedure from 2009 to 2014. Cases were stratified by approach: SILS versus SILS+1 then matched 1:2 on age, gender, body mass index (BMI), comorbidity, and procedure. Demographic, perioperative, and postoperative outcome variables were evaluated. The main outcome measures were operative time, conversion rate, length of stay, complication, morbidity, and mortality rates.

RESULTS

One hundred thirty-two reduced port AR/LAR patients were evaluated-44 SILS and 88 SILS+1. The groups were similar in age, gender, BMI, and ASA class. The primary diagnosis in both cohorts was diverticulitis (90.9 % SILS, 87.5 % SILS+1), and main procedure performed an anterior rectosigmoidectomy (86.4 % SILS, 88.2 % SILS+1). Significantly more SILS+1 patients had previous abdominal surgery (p = 0.01). The operative time was significantly shorter in SILS+1 (mean 166.6 [SD 48.4] vs. 178.0 [SD 70.0], p = 0.03). The conversion rate to multiport or open surgery was also significantly lower with SILS+1 compared to SILS (1.1 vs. 11.4 %, p = 0.02). Postoperatively, the length of stay across the groups was similar. SILS trended towards higher complication and readmission rates (NS). There were no unplanned reoperations or mortality in either group.

CONCLUSIONS

SILS+1 facilitates pelvic and lower abdominal colorectal surgery, with shorter operative times and lower conversion rates. The additional port improved visualization and outcomes without any impact on length of stay, readmission, or complication rates.

Flexible endoscopic single-incision extraperitoneal implant and fixation of peritoneal dialysis catheter: proof of concept in the porcine model

BACKGROUND

Peritoneal dialysis (PD) catheters placed in the pelvic space without anchoring present a high rate of migration. We aimed to assess the feasibility of a single-incision approach, using a flexible endoscopic preperitoneal tunneling for catheter implantation and fixation.

MATERIALS AND METHODS

Eight pigs were involved in this experimental study. A 2/0 Vicryl loop was sutured at the tip of a PD catheter. In 4 pigs, a 1.5 cm incision was made on the left paramedian line and the parietal peritoneal layer was identified by splitting rectal muscles. A gastroscope was inserted in the incision and advanced in the extraperitoneal space. An exit hole was made in the peritoneum over the low pelvic cavity. A guidewire was left in the abdominal cavity, and the PD catheter was inserted over the guidewire. The endoscope was inserted in the tunnel again, and endoscopic clips were deployed over the Vicryl loop to fix the catheter. In 4 pigs, the PD catheter was inserted laparoscopically using a two-port approach. The catheter's tip was fixed with laparoscopic clips on the Vicryl loop. A strain test to assess the force required to detach clips was performed using a digital dynamometer.

RESULTS

Operative time for flexible endoscopic tunneling was longer when compared to the laparoscopic implant (29.5 ± 4.43 vs. 22.7 ± 2.51 min). Mean force to displace the catheter was similar after flexible endoscopic fixation when compared to laparoscopic clip fixation (5.57 N ± 2.76 vs. 4.15 N ± 1.76).

CONCLUSIONS

Flexible endoscopic extraperitoneal tunneling allows for minimally invasive single-incision PD catheter placement and fixation.

A state of the art review and categorization of multi-branched instruments for NOTES and SILS

BACKGROUND

Since the advent of Natural Orifice Translumenal Endoscopic Surgery (NOTES) and single incision laparoscopic surgery (SILS), a variety of multitasking platforms have been under development with the objective to allow for bimanual surgical tasks to be performed. These instruments show large differences in construction, enabled degrees of freedom (DOF), and control aspects.

METHODS

Through a literature review, the absence of an in-depth analysis and structural comparison of these instruments in the literature is addressed. All the designed and prototyped multitasking platforms are identified and categorized with respect to their actively controlled DOF in their shafts and branches. Additionally, a graphical overview of patents, bench test experiments, and animal and/or human trials performed with each instrument is provided.

RESULTS

The large range of instruments, various actuation strategies, and different direct and indirect control methods implemented in the instruments show that an optimal instrument configuration has not been found yet. Moreover, several questions remain unanswered with respect to which DOF are essential for bimanual tasks and which control methods are best suited for the control of these DOF.

CONCLUSIONS

Considering the complexity of the currently prototyped and tested instruments, future NOTES and SILS instrument development will potentially necessitate a reduction of the available DOF to minimize the control complexity, thereby allowing for single surgeon bimanual task execution.

Clinical Evaluation of an Internal Adjustable Retractor in Laparoscopic Cholecystectomy

Introduction. Reducing the number of abdominal incisions in laparoscopic cholecystectomy introduces ergonomic challenges while establishing the critical view during dissection of the triangle of Calot (TC). This study investigates the use of a novel internal retracting device in performing cholecystectomy with a reduced number of ports. Methods. A 3-port laparoscopic cholecystectomy was attempted by 4 surgeons unfamiliar with the novel device. Exposure of the TC was obtained using the internal retractor, which comprises 2 clips, linked by an adjustable thread. One clip is fixed on the gallbladder and the other is fixed to the peritoneum. The endpoint was to evaluate the efficacy and reliability of the device in establishing the critical view of safety. Results. Thirteen patients with a mean body mass index of 25.29 kg/m2(standard deviation = 6.24; range = 17.6-36.7 kg/m2) were included in the study. The critical view was obtained in 10 of 13 patients. Application of the device was completed in a median time of 2.25 minutes without injury of the gallbladder or bile leak. Failure occurred in 3 patients, related to wrong manipulation of the device (2 patients), and correct placement of the device but inadequate exposure (1 patient). A conventional 4-port technique was used in these patients. Operators rated their experience with the device as an “easy-to-operate” device with a good safety profile and without any interference with the operative process. Conclusions. Throughout the minimization process specific to minimal access surgery, internal retractors will certainly allow for a reduction in the number of trocars used in laparoscopic procedures.

Single-incision laparoscopic colorectal surgery for cancer: State of art

A number of clinical trials have demonstrated that the laparoscopic approach for colorectal cancer resection provides the same oncologic results as open surgery along with all clinical benefits of minimally invasive surgery. During the last years, a great effort has been made to research for minimizing parietal trauma, yet for cosmetic reasons and in order to further reduce surgery-related pain and morbidity. New techniques, such as natural orifice transluminal endoscopic surgery (NOTES) and single-incision laparoscopy (SIL) have been developed in order to reach the goal of “scarless” surgery. Although NOTES may seem not fully suitable or safe for advanced procedures, such as colectomies, SIL is currently regarded as the next major advance in the progress of minimally invasive surgical approaches to colorectal disease that is more feasible in generalized use. The small incision through the umbilicus allows surgeons to use familiar standard laparoscopic instruments and thus, perform even complex procedures which require extraction of large surgical specimens or intestinal anastomosis. The cosmetic result from SIL is also better because the only incision is made through the umbilicus which can hide the wound effectively after operation. However, SIL raises a number of specific new challenges compared with the laparoscopic conventional approach. A reduced capacity for triangulation, the repeated conflicts between the shafts of the instruments and the difficulties to achieve a correct exposure of the operative field are the most claimed issues. The use therefore of this new approach for complex colorectal procedures might understandingly be viewed as difficult to implement, especially for oncologic cases.

A novel liver retractor for reduced or single-port laparoscopic surgery

BACKGROUND

Retraction of either lobe of liver is required for surgical access to the respective organ. A novel liver retractor device and technique is described, which applies a vacuum between the liver and diaphragm to lift the liver, and which does not require additional incisions.

METHODS

A novel liver retractor was tested in two anesthetized sheep at incrementally higher levels of suction from -100 to -700 mmHg (-13 to -93 kPa), and any signs of trauma were recorded. The animals recovered for 5 days, then were humanely killed and postmortem examination of the liver and diaphragms performed.

RESULTS

Successful liver retraction was achieved from -200 to -600 mmHg (-27 to -80 kPa) suction. An imprint of the retractor was observed on the liver surface, but there was no breach of the liver serosa. Negligible ecchymoses were observed on the corresponding surface of the diaphragms. Both sheep recovered well after surgery. There was no macroscopic evidence of injury to the liver and diaphragm 5 days postoperatively. Histological examination revealed normal liver parenchyma deep to the site where the devices had been placed, and hemorrhagic changes within the serosa only varied between a few microns to a maximum of 1.4-mm depth.

CONCLUSIONS

The novel liver retractor described achieved an effective liver retraction without trauma. It has potential application in reduced or single-port laparoscopic upper abdominal surgery.

Endoluminal surgical triangulation: overcoming challenges of colonic endoscopic submucosal dissections using a novel flexible endoscopic surgical platform: feasibility study in a porcine model

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) is challenging as a result of the limited ability of conventional endoscopic instruments to achieve traction and exposure. The aim of this study was to evaluate the feasibility of colonic ESD in a porcine model using a novel endoscopic surgical platform, the Anubiscope (Karl Storz, Tüttlingen, Germany), equipped with two working channels for surgical instruments with four degrees of freedom offering surgical triangulation.

METHODS

Nine ESDs were performed by a surgeon without any ESD experience in three swine, at 25, 15, and 10 cm above the anal verge with the Anubiscope. Sixteen ESDs were performed by an experienced endoscopist in five swine using conventional endoscopic instruments. Major ESD steps included the following for both groups: scoring the area, submucosal injection of glycerol, precut, and submucosal dissection. Outcomes measured were as follows: dissection time and speed, specimen size, en bloc dissection, and complications.

RESULTS

No perforations occurred in the Anubis group, while there were eight perforations (50 %) in the conventional group (p = 0.02). Complete and en bloc dissections were achieved in all cases in the Anubis group. Mean dissection time for completed cases was statistically significantly shorter in the Anubis group (32.3 ± 16.1 vs. 55.87 ± 7.66 min; p = 0.0019). Mean specimen size was higher in the conventional group (1321 ± 230 vs. 927.77 ± 229.96 mm(2); p = 0.003), but mean dissection speed was similar (35.95 ± 18.93 vs. 23.98 ± 5.02 mm(2)/min in the Anubis and conventional groups, respectively; p = 0.1).

CONCLUSIONS

Colonic ESDs were feasible in pig models with the Anubiscope. This surgical endoscopic platform is promising for endoluminal surgical procedures such as ESD, as it is user-friendly, effective, and safe.

Single-access laparoscopic rectal surgery is technically feasible

Introduction. Single-access laparoscopic surgery (SALS) has been successfully introduced for colectomy surgery; however, for mid to low rectum procedures such as total mesorectal excision, it can be technically complicated. In this study, we introduced a single-access technique for rectum cancer operations without the use of other instruments. Aims. To show the short-term results of single-access laparoscopic rectal surgery in terms of pathologic results and immediate complications. Settings and Design. Prospective study. Materials and Methods. We selected middle rectum to anal canal cancer patients to undergo single-access laparoscopic rectal resection for rectal cancer. All patients had total mesorectal excisions. An umbilical incision was made for the insertion of a single multichannel port, and a mesocolic window was created to identify the inferior mesenteric artery and vein. Total mesorectal excision was performed. There were no perioperative complications. The mean operative time was 269 minutes; the median hospital stay was 7 days; the mean wound size was 5.5 cm; the median number of harvested lymph nodes was 15; and all patients had intact mesorectal capsules. Statistical Analysis Used. Mean, minimum–maximum. Conclusion. Single-access laparoscopic surgery for rectal cancer is feasible while oncologic principles and patient safety are maintained.

Biopsy with thermally-responsive untethered microtools

Thermally activated, untethered microgrippers can reach narrow conduits in the body and be used to excise tissue for diagnostic analyses. As depicted in the figure, the feasibility of an in vivo biopsy of the porcine bile duct using untethered microgrippers is demonstrated.

Laparoendoscopic single-site surgery in gynecology: LESS is actually how much less?

Gynecological surgery is evolving continuously. Laparoendoscopic single-site surgery (LESS) is the recent addition in this field that stands to benefit almost 40% of women in midlife who will eventually undergo adnexal surgery or hysterectomy. Carried out through a single umbilical incision, the potential benefit of single site surgery is improvement in operative morbidity and cosmesis. The safety, feasibility and efficacy of laparoendoscopic single site procedures have been established in studies over the last few years. In this article, we will review the nomenclature, instruments, and the evidence around the commonly performed gynecologic surgeries using the LESS procedure.

Single-incision laparoscopic colectomy: technical aspects and short-term results

Single-incision laparoscopic surgery (SILS) is currently regarded as the next major advance in the progress of minimally invasive techniques in colorectal surgery. We describe our initial experience using SILS for the management of colorectal disease and present preliminary short-term results. Between February 2010 and April 2011, 7 patients (4 females and 3 males, mean age 55 years, range 32–74) underwent SILS for either benign or malignant colorectal disease. Preoperative diagnosis was diverticular disease of the sigmoid colon in two patients, malignant polyps of the sigmoid colon in two other patients and large villous tumor of the right colon in three patients. Surgical procedures, 4 anterior resections of the rectum and 3 right hemicolectomies, were performed through a 3 cm single umbilical incision using a SILS multi port device with conventional or articulated laparoscopic instruments. There were no intraoperative complications or conversions in the standard laparoscopic procedure. The mean operative time for anterior resections was 160.0 ± 10.6 min, whereas it was 160.6 ± 20 for right hemicolectomies. Blood loss was minimal. No postoperative complications were reported in any of the patients. The overall mean hospital stay was 4.8 ± 0.2 days (range 4–5). For the subset of patients with malignant or pre-malignant disease, the mean number of retrieved lymph nodes was 15.6 ± 4.4 (range 6–31). Cosmetic results were considered excellent by all the patients after 15 days. In conclusion, our preliminary experience shows that SILS for colorectal disease is feasible and safe with potential reproducible oncologic results.

Renaissance of Minilaparoscopy in the NOTES and single port era

The authors suggest that minilaparoscopy should be considered as the most sophisticated evolution of laparoscopic surgery at the present time.

Self-folding devices and materials for biomedical applications

Because the native cellular environment is 3D, there is a need to extend planar, micro- and nanostructured biomedical devices to the third dimension. Self-folding methods can extend the precision of planar lithographic patterning into the third dimension and create reconfigurable structures that fold or unfold in response to specific environmental cues. Here, we review the use of hinge-based self-folding methods in the creation of functional 3D biomedical devices including precisely patterned nano- to centimeter scale polyhedral containers, scaffolds for cell culture and reconfigurable surgical tools such as grippers that respond autonomously to specific chemicals.