Loss Of Tactile Feedback Research Articles

Laparoendoscopic hybrid procedure - Oncologically safe and feasible option for gastrointestinal stromal tumours of the stomach.

Minimally invasive resection of gastrointestinal stromal tumours of the stomach is a feasible alternative to the traditional open approach, without the need for advanced laparoscopic training, as lymph node dissection is not necessary and excision with a negative margin is the only requirement. The loss of tactile feedback is a known drawback of laparoscopic surgery, causing difficulty in assessing the margin of resection. Earlier described laparoendoscopic techniques require advanced endoscopic procedures, which are not readily available in all places. We present a novel method wherein we use an endoscope to guide the resection margins during laparoscopic surgery. In our experience of five patients, we were able to successfully use this technique to get the negative margins pathologically. This hybrid procedure can thus be used to ensure adequate margin, keeping all the benefits of laparoscopic surgery.

Tips for set-up to prevent complications in robotic gynecologic cancer surgery

Robotic surgery (RS) is a breakthrough in gynecologic oncology in the past decade and it is now part of the routine in many centers. Although there is a concern about the oncological outcomes after RS in cervical cancer, it is proven to be safe and effective in endometrial cancer. However, RS has some drawbacks such as the loss of tactile feedback. Complications can therefore occur, and are usually multi-factorial. These can be related to the nature of the operations, the physical fitness of the patients, the control and choice of the devices, and more importantly, the experience and knowledge of the surgical team. To minimise the risk of complications, we need to understand the limitations of RS and have a proper set-up of the operations. It is important to anticipate these potential complications before and during the operations. And a careful setup of the operations, including the instrument set-up, patients’ positioning, port placement, and communication with the anesthetists and surgical team, are crucial in ensuring the safety and success of robotic surgery. In this article, different complications and their preventive measures at set-up were discussed.

Intraoperative Use of Indocyanine Green Fluorescence in Hepatobiliary and Pancreatic Cancer Resections: Current State and Considerations

Introduction: Surgery for hepatobiliary and pancreatic malignancies often has unfavourable outcomes due to incomplete resection, with positive histopathological margins and locoregional metastases. Intraoperative use of indocyanine green fluorescence (ICG) with near-red infrared light can improve tumor detectability and achieve R0 status. Methods: Review of current literature. Results: ICG fluorescence and bile excretion allows for real-time visualisation of malignant tissues and assessment of resection margins. In liver surgery it can identify subcapsular lesions, a property especially useful in minimally invasive surgery where there is loss of tactile feedback and direct visual inspection. It can also delineate hepatic segmental anatomy for anatomical resections. Hepatocellular carcinomas tend to uniformly uptake ICG, whereas primary or metastatic adenocarcinomas like cholangiocarcinomas and colorectal liver metastases as well as poorly differentiated hepatocellular carcinomas show rim enhancement. In pancreatic cancer, fluorescence of the resection margin has been shown to correspond to presence of malignancy on histopathological assessement. ICG can also help to detect micrometastases and extrahepatic spread and distinguish between scar tissue and disease following neoadjuvant chemoradiotherapy. However the technique has limitations: wide variability of method and dose of administration, no visualisation of deep seated lesions, high background fluorescence, false positives up to 40% requiring additional verification by other modalities like intraoperative ultrasound or frozen section for newly detected lesions. Conclusion: ICG fluorescence can offer increased detectability of malignancy and improve post-operative outcomes in hepatobiliary and pancreatic resections. However there are limitations such as superficial depth of detection and low specificity which need improvement to achieve maximum benefit.

Artificial palpation in robotic surgery using haptic feedback.

The loss of tactile feedback in minimally invasive robotic surgery remains a major challenge to the expanding field. With visual cue compensation alone, tissue characterization via palpation proves to be immensely difficult. This work evaluates a bimodal vibrotactile system as a means of conveying applied forces to simulate haptic feedback in two sets of studies simulating an artificial palpation task using the da Vinci surgical robot. Subjects in the first study were tasked with localizing an embedded vessel in a soft tissue phantom using a single-sensor unit. In the second study, subjects localized tumor-like structures using a three-sensor array. In both sets of studies, subjects completed the task under three trial conditions: no feedback, normal force tactile feedback, and hybrid vibrotactile feedback. Recordings of correct localization, incorrect localization, and time-to-completion were used to evaluate performance outcomes. With the addition of vibrotactile and pneumatic feedback, significant improvements in the percentage of correct localization attempts were detected (p = 0.0001 and p = 0.0459, respectively) during the first experiment with phantom vessels. Similarly, significant improvements in correct localization were found with the addition of vibrotactile (p = 2.57E-5) and pneumatic significance (p = 8.54E-5) were observed in the second experiment involving tumor phantoms. This work demonstrates not only the superior benefits of a multi-modal feedback over traditional single-modality feedback, but also the effectiveness of vibration in providing haptic feedback to artificial palpation systems.

Commentary to “Prechemotherapy laparoscopic nephrectomy for Wilms' tumor”

The authors report two cases of laparoscopic nephrectomy for Wilms’ tumor performed prior to the administration of chemotherapy (only one of which is a typical Wilms’ tumor in a child). The timing of surgery is important because preoperative chemotherapy reduces tumor size and the risk of intraoperative tumor rupture. Therefore, a laparoscopic approach will generally be more challenging when performed prior to chemotherapy administration. As the authors acknowledge, this report merely demonstrates the feasibility of the operation; being a single case report it tells us nothing significant regarding the advantages, morbidity or risks. One potential advantage of a laparoscopic approach, whether before or after chemotherapy, is decreased morbidity in terms of postoperative pain and length of hospital stay. These advantages are of limited concern in small children who recover quickly in any case. And for patients with Wilms’ tumor, the total hospitalization during treatment of their disease is going to be driven primarily by the adjuvant therapy they will receive postoperatively rather than by the recovery from the operation itself. The other potential advantage of a laparoscopic approach is cosmesis. The scar of a transverse abdominal incision does become a concern to some children when they are older. And although a significant incision is still required to extract the tumor intact, a Pfannenstiel incision is significantly less apparent later in life than the traditional open surgical incision. That said, what are the potential risks of a laparoscopic approach? The authors mention the two most important: an increased risk of intraoperative tumor rupture due to loss of tactile feedback and an inadequate abdominal

Reduced postural sway during quiet standing by light touch is due to finger tactile feedback but not mechanical support

It is well known that a light and voluntary touch with a fingertip on a fixed surface improves postural stability during quiet standing. To determine whether the effect of the light touch is due to the tactile sensory input, as opposed to mechanical support, we investigated the light touch effect on postural stability during quiet standing with and without somatosensory input from the fingertip. Seven young subjects maintained quiet standing on a force platform with (LT) and without (NT) lightly touching a fixed surface, and with (TIS) and without (CON) the application of tourniquet ischemia, which removed the tactile sensation from the fingertip. The mean velocity of centre of pressure (CoP) was calculated to assess the postural sway in each condition. The mean velocity of CoP was significantly smaller in the LT condition compared to the NT condition only under the CON condition, whereas the light touch effect was not significant under the TIS condition. We found that the reduction of the horizontal ground reaction force due to the light touch was about 20%, which was approximately equivalent to the reduction of mean velocity of CoP in the LT condition compared to the NT condition. Since the fingertip contact force was relatively large compared to the horizontal ground reaction force, one could say that the light touch effect might be due to the mechanical support provided by the contact itself. However, we demonstrated experimentally that light touch effects were diminished due to loss of finger tactile feedback induced by the tourniquet ischemia, but not due to the mechanical support provided by the light touch. One possible reason is the lack of feedback information in controlling posture, and the other is the altered control of the arm induced by the loss of tactile feedback.

Enhanced Surgical Imaging: Laparoscopic Vessel Identification and Assessment of Tissue Oxygenation

Inherent to minimally invasive procedures are loss of tactile feedback and loss of three-dimensional assessment. Tasks such as vessel identification and dissection are not trivial for the inexperienced laparoscopic surgeon. Advanced surgical imaging, such as 3-charge-coupled device (3-CCD) image enhancement, can be used to assist with these more challenging tasks and, in addition, offers a method to noninvasively monitor tissue oxygenation during operations. In this study, 3-CCD image enhancement is used for identification of vessels in 25 laparoscopic donor and partial nephrectomy patients. The algorithm is then applied to two laparoscopic nephrectomy patients involving multiple renal arteries. We also use the 3-CCD camera to qualitatively monitor renal parenchymal oxygenation during 10 laparoscopic donor nephrectomies (LDNs). The mean region of interest (ROI) intensity values obtained for the renal artery and vein (68.40 +/- 8.44 and 45.96 +/- 8.65, respectively) are used to calculate a threshold intensity value (59.00) that allows for objective vessel differentiation. In addition, we examined the renal parenchyma during LDNs. Mean ROI intensity values were calculated for the renal parenchyma at two distinct time points: before vessel stapling (nonischemic) and just before extraction from the abdomen (ischemic). The nonischemic mean ROI intensity values are statistically different from the ischemic mean ROI intensity values (p < 0.05), even with short ischemia times. We have developed a technique, 3-CCD image enhancement, for identification of vasculature and monitoring of parenchymal oxygenation. This technique requires no additional laparoscopic operating room equipment and has real-time video capability.

Laparoscopy for benign disease: robotics.

Currently available robotic surgical systems appear to be particularly suited for use in benign diseases of the gastrointestinal system. Minimally invasive operations for foregut conditions, such as gastroesophageal reflux disease and achalasia, require excellent visibility and precise tissue dissection. Benign lower gastrointestinal diseases, including inflammatory bowel disease and diverticulitis, also can be approached using robotic assistance. Disadvantages include expense and the loss of tactile feedback. Early clinical results are promising.