Single Access Port Research Articles

Effect of insufflation pressure during transanal minimally invasive surgery on surgical complications with dissection of the rectal submucosa in canine cadavers.

To determine ideal insufflation pressures during transanal minimally invasive surgery (TAMIS) in canine cadavers for rectal submucosal transection and incisional closure. 16 canine cadavers. Cadavers were placed in lateral recumbency. Urinary catheters were placed to measure intra-abdominal pressure (IAP). A single access port was placed to establish a pneumorectum. Cadavers were placed in insufflation groups of 6 mmHg to 8 mmHg (group 1), 10 mmHg to 12 mmHg (group 2), or 14 mmHg to 16 mmHg (group 3). Defects in the rectal submucosa were created and closed with a unidirectional barbed suture. Duration for each procedure and subjective ease of identifying the transection plane and performing incisional closure were assessed. The single access port was successfully placed in dogs weighing 22.7 kg to 48 kg. The ease of each step of the procedure was not influenced by the insufflation pressure. The median surgical duration for group 1 was 740 seconds (range = 564 to 951 seconds), 879 seconds (range = 678 to 991 seconds) for group 2, and 749 seconds (range = 630 to 1,244 seconds) for group 3 (P = .650). The insufflation pressure increased the IAP (P = .007). Perforation of the rectum happened in 2 cadavers in group 3. The duration of each step of the procedure was not significantly influenced by insufflation pressure. Defining the dissection plane and performing resection was more challenging in the highest-pressure group. Rectal perforation occurred only with the 14 mmHg to 16 mmHg insufflation pressure. Single access port usage with TAMIS may provide a readily available, minimally invasive approach for the resection of rectal tumors in dogs.

Extracting RLC Parasitics From a Flexible Electronic Hybrid Assembly Using On-Chip ESD Protection Circuits

The presence of RLC line parasitics in a flexible hybrid electronic assembly can lead to signal integrity issues, and their progression over time can lead to catastrophic failures. A technique for extracting the RLC line parasitics from a flexible hybrid electronics assembly is presented. The proposed extraction method exploits the on-chip ESD protection circuits of an IC chip to extract the parasitics of the printed conductors bonded to the chip. This is performed through a single test access port, i.e., two test points. While the parasitics LC are extractable through one-port reflection-based techniques such as time domain reflectometry; the parasitic R requires a two-port measurement such as Kelvin test, which is extremely difficult to perform for printed conductors bonded to small surface-mount IC package devices. The accuracy of the extracted RLC parameters with the proposed method are verified with a prototype developed on a rigid FR4 substrate. Subsequently, the proposed technique is utilized to track the variation of the RLC parasitics for prototypes developed on Kapton Polyimide substrate subjected to different forms of bending.

Three-dimensional interferometric stage encoder using a single access port

We present a novel multi-dimensional positional encoder approach that uses range-resolved interferometry (RRI) to simultaneously interrogate multiple interferometers differing in optical path length, using only a single photo detector and a single diode laser. Employing only stage-mounted non-polarising beamsplitters and reflections from three orthogonal, externally mounted, planar mirrors, three Cartesian measurement directions are formed, that when combined with measurements from a stage-mounted reference reflection, allow for three-dimensional measurements of stage motion obtained via a single access port. Through a variety of movements of a three-dimensional Piezo-electric stage over its nominal stage working range of ± 50 μm, simultaneous measurements of displacements from three orthogonal dimensions are acquired with a 10 kHz quadrature bandwidth, achieving typical displacement noise densities of below 0.4 nm/Hz, with the noise floor dropping to below 0.1 nm/Hz above 50 Hz, as well as high linearity with cyclic errors amplitudes well below 1 nm in all three directions.

2D Spatially-Resolved Depth-Section Microfluidic Flow Velocimetry Using Dual Beam OCT.

A dual beam optical coherence tomography (OCT) instrument has been developed for flow measurement that offers advantages over microscope derived imaging techniques. It requires only a single optical access port, allows simultaneous imaging of the microfluidic channel, does not require fluorescent seed particles, and can provide a millimetre-deep depth-section velocity profile (as opposed to horizontal-section). The dual beam instrument performs rapid re-sampling of particle positions, allowing measurement of faster flows. In this paper, we develop the methods and processes necessary to make 2D quantitative measurements of the flow-velocity using dual beam OCT and present exemplar results in a microfluidic chip. A 2D reference measurement of the Poiseuille flow in a microfluidic channel is presented over a spanwise depth range of 700 μm and streamwise length of 1600 μm with a spatial resolution of 10 μm, at velocities up to 50 mm/s. A measurement of a more complex flow field is also demonstrated in a sloped microfluidic section.

Method and apparatus for measuring the stability of large lateral transfer retroreflectors through a single optical port.

Achieving precise alignment between spatially separated optical axes is a challenging problem in optical applications such as boresighting, rangefinding, laser tracking, and optical beam delivery. The Advanced Topographic Laser Altimeter System (ATLAS) developed for NASA's Ice, Cloud and Land Elevation Satellite-II (ICESat-2) mission launched in 2018 was one such application where the alignment of the transmitter laser beam to the receiver telescope is critical for the operation of the instrument. This paper discusses a novel approach for verifying the stability of high-precision beam pointing in the conditions of the Thermal Vacuum (TVAC) test, developed for ATLAS testing at NASA Goddard Space Flight Center. It includes a method and an optical assembly that enables measuring tiny variations in the pointing of the beams of a large lateral transfer retroreflector through a single optical access port such as a TVAC chamber window. The method can be applied for verifying the alignment of optical beams separated by extended distances of tens of meters in vacuum.

Metre-per-second microfluidic flow velocimetry with dual beam optical coherence tomography.

A novel dual beam Optical Coherence Tomography (OCT) instrument has been developed for high velocity flow measurement, principally in microfluidics applications. The scanned dual beam approach creates a pair of image-frames separated by a small spatiotemporal offset. Metre-per-second flow measurement is achieved by rapid re-imaging by the second beam allowing for particle tracking between each image-frame of the pair. Flow at 1.06 m/s using a single optical access port has been measured, more than two orders of magnitude larger than previously reported OCT systems, at centimetre depth and with millimetre scale depth of field within a microfluidic chip, whilst simultaneously imaging the microfluidic channel structure.

Robotic-Assisted Transrectal Cholecystectomy in a Porcine Model.

Background. With increasing experience and technological advancement in surgical instruments, surgeons have explored the feasibility of single-incision laparoscopic surgery and natural orifice transluminal endoscopic surgery (NOTES). These techniques aim to further reduce surgical trauma, but are not popular due to their inherent pitfalls including clashing of instruments, lack of counter traction, lengthy operating time, and so on. A novel surgical robotic system was designed to overcome the limitations of the existing technologies. Animal trials were conducted to demonstrate its feasibility in performing robotic-assisted transrectal cholecystectomy in a porcine model. Method. The Novel surgical robotic system is a high dexterity, single access port surgical robotic system that enables surgeons to carry out single-port surgical procedure or NOTES. The proposed system's main features include the ability to perform intraabdominal and pelvic surgeries via natural orifices like the vagina or rectum. The system is equipped with multiple miniaturized (16 mm diameter) internally motorized robotic arms, each with a minimum of 7 degrees of freedom, a dual in vivo camera system, a cannula, and an external swivel system. Results. Robotic-assisted transrectal cholecystectomy was successfully performed in 3 adult male pigs. The estimated blood loss was <10 mL in all 3 cases. There were no intraoperative complications. The system provided good dexterity and clear vision. Conclusions. The trial demonstrated that the system can provide the surgeon a stable platform with adequate spacing for the transrectal insertion of robotic arms, 3-dimensional vision, and enhanced dexterity in performing NOTES cholecystectomy.

MP03-12 SUITABLE PATIENTS FOR SINGLE-PORT LAPAROSCOPIC ADRENALECTOMY: OPTIMAL CUT-OFF VALUE OF BODY MASS INDEX

You have accessJournal of UrologyAdrenal1 Apr 2018MP03-12 SUITABLE PATIENTS FOR SINGLE-PORT LAPAROSCOPIC ADRENALECTOMY: OPTIMAL CUT-OFF VALUE OF BODY MASS INDEX Kazuhiro Matsumoto, Keishiro Fukumoto, Akira Miyajima, Masanori Hasegawa, Toshikazu Takeda, Eiji Kikuchi, Hiroshi Asanuma, and Mototsugu Oya Kazuhiro MatsumotoKazuhiro Matsumoto More articles by this author , Keishiro FukumotoKeishiro Fukumoto More articles by this author , Akira MiyajimaAkira Miyajima More articles by this author , Masanori HasegawaMasanori Hasegawa More articles by this author , Toshikazu TakedaToshikazu Takeda More articles by this author , Eiji KikuchiEiji Kikuchi More articles by this author , Hiroshi AsanumaHiroshi Asanuma More articles by this author , and Mototsugu OyaMototsugu Oya More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.3055AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recently, the single-port approach has attracted attention with evolution to less invasive surgery, but it is considered that single-port surgery should be performed by experienced surgeons because of the difficulties. In this study, we tried to identify the patients who were suitable for single-port laparoscopic adrenalectomy, focusing on the optimal cut-off values of the body mass index (BMI) and the visceral fat area / total fat area (VFA/TFA) ratio. It is hoped that the results will be useful for making decisions about the surgical approach to adrenal tumors. METHODS A retrospective study was conducted in 126 consecutive patients who underwent single-port adrenalectomy between 2009 and 2015. All operations were done via the transperitoneal approach, after a single access port (SILS port) was placed at the umbilicus with a 2.5 cm skin incision. For right adrenalectomy, an additional 2-mm port was used for liver retraction. We used a 5 mm flexible camera, as well as flexible devices (SILS clinch and SILS hook) and energy devices (Enseel or Ligasure). TFA and VFA were measured at the L4 level on preoperative CT scans. The pneumoperitoneum time (PT) was employed as an objective index for the assessment of surgical difficulty. RESULTS Figure 1 is a bar graph of the mean PT for each BMI range, demonstrating that the cut-off value for BMI is 24 kg/m2. In 80 patients with a BMI less than 24 kg/m2, PT was significantly shorter than in those whose BMI exceeded 24 kg/m2 (78 vs. 94 minutes, p=0.038). Mean PT was 71 minutes in 27 patients with a BMI less than 20 kg/m2, while mean PT was 134 minutes in 9 patients with a BMI exceeding 28 kg/m2. Figure 2 shows the mean PT in each range of the VFA/TFA ratio, demonstrating a clear cut-off value of 0.4 for this ratio. PT was shorter in 65 cases with a VFA/TFA ratio less than 0.4 than in those with a ratio exceeding 0.4 (78 vs. 91 minutes, p=0.056). CONCLUSIONS BMI is associated with the PT for single-port laparoscopic adrenalectomy, and the optimal cut-off value is 24 kg/m2. Patients with a BMI less than 20 kg/m2 are thought to be suitable for novice surgeons. Conversely, even experienced surgeons should carefully consider performing single-port surgery in patients whose BMI exceeds 28 kg/m2. The VFA/TFA ratio was also a predictor of the technical difficulty of single-port surgery, and its optimal cut-off value was 0.4. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e26-e27 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Kazuhiro Matsumoto More articles by this author Keishiro Fukumoto More articles by this author Akira Miyajima More articles by this author Masanori Hasegawa More articles by this author Toshikazu Takeda More articles by this author Eiji Kikuchi More articles by this author Hiroshi Asanuma More articles by this author Mototsugu Oya More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Evaluation of efficacy of repeated decontamination and sterilization of single-incision laparoscopic surgery ports intended for 1-time use.

To determine the efficacy of repeated decontamination and sterilization of a disposable port intended for 1-time use during single-incision laparoscopy. Experimental; prospective, controlled design. Six single-access ports used 4 times and 6 single-access ports used 8 times to perform various clean, minimally invasive surgeries were evaluated. Ports were decontaminated in an enzymatic cleaner (dilution, 3:100) and cleaned with a scrub brush for 5 minutes. The ports were then sterilized with hydrogen peroxide vapor for 50 minutes using a standard protocol at a concentration of 6 mg/L, followed by a vapor diffusion phase. Samples taken from the foam, insufflating tubing, and rigid cannula portion of each port were collected with aseptic technique for aerobic-anaerobic cultures. Port material samples were set up on a tryptic soy agar plate with 5% sheep blood, a MacConkey agar plate, and a Columbia agar plate with 5% sheep blood (CAP). Anaerobic isolate cultures were set up on Centers for Disease Control and Prevention (CDC) blood agar and CAP. None of the ports used 4 times had positive bacteriologic culture. Two of the ports used 8 times had a light growth of bacteria. The first positive sample cultured Staphylococcus spp. and Micrococcus spp. The second positive sample cultured Staphylococcus epidermidis. The positive cultures were obtained from the foam component in an enriched broth. Single-incision ports could be used safely 4 times and pose a low risk of infection to the patient under conditions of this study.

Fiber Optic Sensors Based on Fiber Bragg Gratings for Methanol Steam Reforming Temperature Monitoring

This work describes the use of sensors based on fiber Bragg gratings (FBGs) to monitor the variation in the temperature gradients in a catalyst plate in a steam reforming metal plate test reactor. Steam reforming consists of a series of chemical reactions between steam, a hydrocarbon fuel (such as methane) and carbon monoxide taking place over a catalyst layer with the ultimate goal of producing hydrogen. Methane steam reforming is currently the principal technique used for hydrogen generation and is likely to increase in terms of production volume in the future as commercial fuel cell applications become more widespread. The amount of hydrogen obtained from these reactions is inherently linked to the process temperature which is in turn influenced by the heat transfer characteristics of the reformer. Steam reforming is a very endothermic process and it is extremely challenging to achieve fast response and good load following of the fuel cell power demand. FBGs can be used to obtain critical information to improve the load response and maximize the power density of compact heat-exchange reformers. Currently, non-contact instruments, such as single point radiometers and thermal imagers, are used to measure the temperature in methane steam reforming reactors. Many issues are linked with these measurement tools such as inaccuracies in the results due to difficulties associated with calibration which depends on the surface characteristics and operating conditions. Moreover, temperature measurements are localised and in commercial reformer design, access to some sections of the reformer is not possible during operation. Consequently, obtaining a temperature profile across the reformer is challenging. In this work, a fiber-optic sensor based on FBG technology is used to monitor temperature directly on the catalyst plate of a small-scale experimental reactor. An in-fibre Bragg grating occupies a short length (typically 2 mm-10 mm) of an optical fibre and is comprised of regions of modified refractive index photo-inscribed at regular intervals along the length of the fibre core. When light propagating in an optical fibre encounters a grating, a narrow band of wavelength is preferentially reflected. The center-wavelength of this reflected band (i.e., the Bragg wavelength) is a function of the refractive index of the fibre core and of the grating spacing. When the fibre is subjected to mechanical or thermal strain, both the refractive index of the fibre core and the grating spacing change and there is a corresponding shift in the Bragg wavelength that can be related to the magnitude of the applied strain or temperature change. FBGs are well suited for temperature measurements in steam reforming reactors. Multiple FBGs can be located on a single fibre and interrogated independently. This allows multiple measurements to determine the temperature gradient across a reformer tube while requiring only a single access port for the fiber into the reformer. Furthermore, the small sensor size allows high spatial resolution of the temperature gradient. In addition, optical fiber is able to withstand the harsh chemical conditions and high temperatures under which steam reforming takes place. The insertion of a fiber-optic sensor directly in the reactor and located under the catalyst plate aims to resolve the issues currently associated with temperature monitoring in methane steam reforming reactors and provide an accurate measurement of the temperature profile along the length of the catalyst plate using multiplexed Bragg gratings. Experiments were conducted with regenerated type-I FBGs written in standard SMF-28e germanium doped fiber using UV exposure. Type-I gratings erase when exposed to temperatures of the order of 400 °C for extended periods of time. Regeneration is a high temperature (>900 °C) annealing process which leads to the formation of gratings that have been shown to be stable at temperatures as high as 1295 °C. Due to the fragility of the fiber following the annealing process, the FBG is first positioned in the custom-modified reactor and the gratings are regenerated in-situ. Multiplexed gratings are used to obtain a temperature profile, which is generated by electric heaters, in the metal plate test reactor. The temperature profiles acquired with the regenerated FBGs during reforming are reported and compared with the reference temperature profiles obtained with K-Type thermocouples, also embedded in the reactor.

Malignant Osteolytic Lesions in the Sacrum (S1-S3) Treated by Targeted Radiofrequency Ablation: A New Option for Metastases in the Sacrum

Introduction Sacral metastases and myelomatous lesions often result in debilitating pain and significant morbidity in patients with prolonged life expectancy. Radiation therapy and cement augmentation are well described local therapies for controlling cytokine mediated osteolytic bone resportion and skeletal related events associated with metastatic and myelomatous sacral lesions. Ablative therapy has been reported in recent years as a minimally invasive therapy permitting both local treatment of bone lesions and immediate stabilization, when followed with cement augmentation. This case study reports multimodality minimally invasive treatment of patient with multiple painful osteolytic lesions using a novel articulating bipolar RF ablative therapy and an ultrahigh viscosity cement. Material and Methods A 75-year-old-patient with history of multiple myeloma and significant lumbar back pain presented with diffuse lytic spinal disease throughout the thoracolumbar and sacral spine. Following review by multidisciplinary tumorboard, percutaneous targeted radiofrequency ablation (t-RFA) was performed in T12-L4 and a unilateral sacral lesion (S1-S3) using an articulated bipolar electrode containing thermocouples to assess real time growth of the ablation zone followed by delivery of ultrahigh viscosity cement using RF energy warmed cement (RF-Targeted Vertebral Augmentation, RF-TVA). Pain was demonstrated preoperatively with 9 using the visual analog scale for both locations. On the first postoperative day pain was at 4(VAS), in the 6 weeks control pain was at 2(VAS). At the 3 months control pain was at 2(VAS). Results The combined approach of t-RFA and RF-TVA in the sacrum was technically and clinically feasible with an immediate pain reduction, improvement in quality of life and functionality at 6 weeks and 3 months after the procedure and no complications. CT performed 6 weeks post procedure confirmed the absence of cement leakage. Conclusion t-RFA combined with RF-TVA of the sacrum can be safely and effectively performed via a single access port resulting in significant palliative relief and functional improvement. In combination these procedures may provide an alternative palliative, minimally invasive treatment option for painful osteolytic lesions in the sacrum(S1-S3) requiring stabilization for patients in which radiation therapy may not be an option.

Current status of robotic single-port colonic surgery.

The present paper reviews evidence and examines updates in single-port robotic surgery for colonic diseases reported in contemporary studies. A comprehensive online systematic search of PubMed databases was carried out in June 2015, identifying studies conducted on robotic single-port colectomy from 2008 to 2015. The advantages and disadvantages of several available port-access systems, techniques for configuring robotic arms, and robotic surgical platforms, were presented. Current studies show that single-port robotic colectomy is a safe and feasible procedure despite the lack of supporting evidence. Although significant advancements in the development and modification of single-access ports, configuration of robotic arms, and robotic surgical platforms have been achieved in the field of single-port robotic surgery for colonic disease, significant improvements to surgical platforms for single-port robotic surgery are needed. Copyright © 2016 John Wiley & Sons, Ltd.

Single-port videoscopic splanchnotomy for palliation of refractory chronic pancreatitis

Interrupting the afferent signals that travel through the splanchnic nerves by multiportal thoracoscopic splanchnotomy can offer effective palliation in chronic pancreatitis. However, obtained results weaken after time, possibly necessitating repeat procedures. Given the palliative nature of this procedure, potential for iatrogenic damage should be kept at a minimum. So, in order to minimize invasiveness while optimizing repeatability, we sought to create an easily reproducible single-access port operative strategy. Four patients suffering from intractable pain due to chronic pancreatitis for >10 years (12.8 ± 5.9) underwent a single-port unilateral R5-R11 splanchnotomy. Postoperative recovery was uneventful. No operative complications were observed. All 4 patients experienced excellent pain relief with a significant improvement of Visual Analogue Scale pain scores (8.8 ± 1.0 preoperatively to 3.0 ± 1.2 postoperatively, P = 0.003). We report the first series of single-port video-assisted thoracoscopic surgical (VATS) splanchnotomy for palliation of intractable pain due to chronic pancreatitis. From this small study, single-port VATS splanchnotomy seems to be a safe and effective alternative to multiportal or open procedures.

Supporting evidence for robotic urological surgery

Since the introduction of the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA), the trend of minimally invasive surgery has accelerated. Recently, Intuitive Surgical launched the new da Vinci Xi platform and a prototype of a single-port surgical system. Other platforms from other robotic companies are on the horizon. The multiport surgical robotic ALF-X system (SORAR SpA, Milan, Italy) was initially introduced for gynecological surgery and was recently assessed in a preclinical animal study of robot-assisted partial nephrectomy (RPN) [1,2]. The ALF-X robot consists of a remote-controlled unit with a haptic handle, a three-dimensional high-definition monitor, an infrared eye-tracking system, and four detached robotic arms. The haptic feedback allows the surgeon to feel the force and resistance to the tissue. The surgeon can move the camera by gaze, and the system includes a large set of reusable instruments. Other manufacturers include Medrobotics (Raynham, MA, USA), which received U.S. Food and Drug Administration clearance for the Flex Robotic System in July 2015. The Flex Robotic System provides surgeons with single-site access visualization of hard-to-reach anatomical locations. Titan Medical (Toronto, ON, Canada) is a public company based on Single Port Orifice Robotic Technology. The system utilizes a 25-mm single-access port that contains two articulating instruments and a three-dimensional high-definition camera. The Korean domestic manufacturer Meree Company has developed the REVO I robot system. A clinical trial for the REVO I robot has been planned to supplement the global market. Meanwhile, the Korean national evidence-based health care collaborating agency (NECA) published a preliminary report on the clinical feasibility and cost-effectiveness of robot-assisted radical prostatectomy (RARP) from a total of five high-volume centers to provide fundamental data for instituting the national health policy. Concerning oncological outcomes, there were no significant differences in biochemical recurrence or the positive surgical margin rate. Concerning functional outcomes, RARP revealed the highest continence rate of 88.7% and 95.3% achievement of complete continence at postoperative 3 months and 3 years, respectively. Concerning cost analysis of the robotic system, with a threshold value of 30.5 million Korean won (KRW; 27,000 US dollars [USD]), a cost-effectiveness analysis of purchase among RARP, laparoscopic radical prostatectomy, and open radical prostatectomy (ORP) showed that RARP was not yet cost-effective. RARP could be cost-effective if the expenses could be reduced by 8.3 million KRW (7,400 USD). The effectiveness of the system could not offset the costs, because there was no significant difference in effectiveness among the different procedures, and the robotic cost of RARP was significantly more than that of the other procedures. However, owing to the short term of 1 year of data used for the cost-effectiveness analysis, long-term prospective study is necessary for further high-quality analysis. Recently, high-quality evidence is emerging comparing robotics with its traditional counterparts. In a study of RARP, Wallerstedt et al. [3] performed a prospective comparative trial of ORP versus RARP in a Swedish group of 14 centers including a total of 2,506 patients. The study was conducted prospectively over a 3-year period with patient-reported outcome measurement. The RARP group had less perioperative bleeding and shorter hospital stays. Reoperation during the hospital stay and seeking health care for cardiovascular reasons were more frequent after ORP. Haglind et al. [4] performed a prospective, controlled, nonrandomized trial evaluating urinary incontinence and erectile dysfunction in a total of 14 centers in Sweden including 2,625 patients and concluded that RARP was beneficial in preserving erectile function compared with ORP, with no statistically significant differences in continence or surgical margins. In an analysis of RPN, Choi et al. [5] performed a systematic review and meta-analysis of 23 studies and 2,240 patients. The authors concluded that RPN is more favorable than laparoscopic partial nephrectomy (LPN) in terms of a lower conversion rate to radical nephrectomy, more favorable renal function, a shorter length of hospital stay, and a shorter warm ischemia time. Potretzke and Bhayani [6] wrote an editorial comment on our previous article [5]. The authors mentioned the superior outcomes of RPN and the efficiency of excision and suturing. The true value of RPN is in its feasibility, accessibility, and learning curves, and the procedure competing with RPN now is not LPN, but rather radical nephrectomy, ablation, and observation. There will be more new robotic platforms, and new prospective randomized data will become available. The Korean Journal of Urology hopes to continue to share this knowledge on recent updates in robotic minimally invasive surgery and to enhance future perspectives on robotic minimally invasive surgery.

Configuration comparison among kinematically optimized continuum manipulators for robotic surgeries through a single access port

SUMMARYMany recent developments of surgical robots focus on less invasive paradigms, such as laparoscopic SPA (Single Port Access) surgery, NOTES (Natural Orifice Translumenal Endoscopic Surgery), laryngoscopic MIS (Minimally Invasive Surgery), etc. A configuration similarity shared by these surgical robots is that two or more manipulators are inserted through one access port (a laparoscope, an endoscope, or a laryngoscope) for surgical interventions. However, upon designing such a surgical robot, the structure of the inserted manipulators has not been thoroughly explored based on evaluation of their performances. This paper presents a comparison for kinematic performances among three different continuum manipulators. They all could be applied in the aforementioned surgical robots. The structural parameters of these continuum manipulators are firstly optimized to assure a more fair and consistent comparison. This study is conducted in a dimensionless manner and provides scalable results for a wide spectrum of continuum manipulator designs as long as their segments have a constant curvature. The results could serve as a design reference for future developments of surgical robots which use one access port and continuum mechanisms.

Erratum to: Transanal endoscopic surgery using a single access port: a practical tool in the surgeon’s toybox

Erratum to: Transanal endoscopic surgery using a single access port: a practical tool in the surgeon’s toybox

Transanal endoscopic surgery using a single access port: a practical tool in the surgeon’s toybox

Large polyps and early carcinomas of the rectum may be excised with transanal endoscopic surgery (TES). Single-port techniques are emerging in the field of colorectal surgery and have been adapted to many colorectal procedures so far. In this article, we aimed to present our initial experience with TES using a single access port with its technical details. Patients undergoing TES using a single access port between July 2010 and January 2013 were included in the study. Patient demographics, operative technique, and both operative and postoperative outcomes were evaluated and presented. A total of 12 patients (ten males) were included in our study. The median age was 63.5 years (50-84), median American Society of Anesthesiologists (ASA) score was 3 (2-4), and median body mass index was 28.8 kg/m(2) (17.4-55.6). Median operating time was 79 min (43-261). Histopathological diagnoses were as follows: tubulovillous adenoma (n = 6), tubular adenoma (n = 4), adenocarcinoma (n = 1), and neuroendocrine tumor (n = 1). Five patients were sent home on the day of surgery and the median postoperative hospital stay was 1 day (0-38). Median estimated blood loss was 22.5 ml (5-150). A transient urinary retention was developed in one patient postoperatively, and two patients had postoperative bleeding. The first of these patients with a long history of anticoagulant usage had rectal bleeding 13 days after surgery, which was successfully managed with medical treatment. The second patient was morbidly obese, had multiple comorbidities, and had rectal bleeding on postoperative day 7 which was managed with local epinephrine injection. He suffered unrelated cardiac death on postoperative day 38. TES is safe and feasible when using a single port and in the standard laparoscopic setting. The single-port technique may play a major role in the widespread utilization of TES as a treatment for large adenomas and early rectal cancers.

A prospective observational study on 249 subcutaneous central vein access ports in a Swedish county hospital

Background. Reliable central vein access is a fundamental issue in modern advanced oncological care. The aim of this study was to determine the incidence of complications and patient perception regarding central vein access ports. Methods. We prospectively studied 249 single lumen access ports implanted between 1 July 2008 and 15 March 2010 in a mixed patient population at a 500-bed secondary level hospital in Sweden. We determined the number of catheter days, infection rate and mechanical complications, as well as patient satisfaction regarding the access port, over a six-month follow-up period. Results. Two hundred and forty-four different patients received 249 ports yielding a total of 37 763 catheter days. Ultrasound and fluoroscopic guidance was used in 98% of procedures. Vein access was obtained percutanously by an anaesthesiologist in all cases. There was no case of pneumo- or haemothorax. The incidence of catheter-related bloodstream infection, was 0.05/1000 catheter days and the incidence of pocket/tunnel infection was 0.39/1000 catheter days. Clinically apparent deep vein thrombosis occurred in four patients (1.6%). Patient satisfaction was overall high. Conclusion. These results confirm that our team-based approach with written easily accessible evidence-based guidelines and a structured education programme leads to a very low complication rate and a high degree of patient satisfaction.

Single incision laparoscopic right hemicolectomy: different approaches

Background Single incision laparoscopic colectomy has been performed in recent years, and has been shown to be feasible and safe. This study was to assess the feasibility of single incision laparoscopic right hemicolectomy and to compare the differences in different approaches. Methods This retrospective study included eighteen patients with carcinoma of caecum and ascending colon, undergoing single incision laparoscopic right hemicolectomy. This study also compared single incision laparoscopic right hemicolectomy using different approaches: (1) single incision multiport, (2) single access port and (3) glove port. Results There was no statistical difference in surgical outcomes. Concerning the surgeon's satisfaction toward three methods, overcrowding and durability were similar but the single incision multiport was associated with the highest gas-leak and the “glove” port was associated with poor durability. However, the method of single incision multiport has the lowest average cost of the special trocar or port in each operation. The operative time and blood loss of the operations in this study were comparable to previous publications. Conclusion There was no significant difference between different approaches of single incision laparoscopic right hemicolectomy for colonic cancer in right side colon.

A novel robotic system for single-port laparoscopic surgery: preliminary experience

The concept of single-access procedures has gained greater attention from general surgeons during the past 5 years. Despite this wide momentum, these procedures pose several changes for the surgeon, such as impaired eye-hand coordination and restricted manipulation. In this context, robotic-assisted surgery represents a promising technology to enhance the dexterity of laparoscopic surgeons. A novel teleoperated robotic system for minimally invasive surgery (MIS) called SPRINT (Single-Port lapaRoscopy bImaNual roboT) has been developed. SPRINT is a master-slave robotic platform designed for bimanual interventions through a single-access port. The system is basically composed by two main arms having a maximum diameter of 18 mm and a stereoscopic-camera (Karl-Storz, Tuttlingen, Germany). The arms may be inserted into a cylindrical introducer that has a maximum diameter of 30 mm. The surgeon console is composed of two master manipulators, a foot-switch, and a 3D full-HD display. In an animal study, a small-bowel enteroenterostomy and the ligation of a mesenteric vessel bundle have been performed. As preliminary experience, the system has been placed within the peritoneal cavity through an incision of approximately 10 cm: the robot has been suspended in an open fashion, due to some mechanical constraints of the current prototype. The procedures have been performed in an authorized laboratory on a female pig of approximately 50 Kg. Two typical surgical maneuvers have been performed successfully with the SPRINT surgical platform: an intestinal anastomosis and a vessel ligation. Moreover, the speed, precision, and force with which the SPRINT robot executed the commands by the surgeon controlling the master console have been subjectively described as adequate to the tasks. Based on this preliminary demonstration, bimanual robot solutions, such as the SPRINT robot, may offer more dexterity and precision to single-port techniques in the next future.