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Biomedical subjects

D Oleynikov

Publications and source records attributed to D Oleynikov.

9 recordsLinked to original sources

Robotic surgery and training: electromyographic correlates of robotic laparoscopic training.

BACKGROUND: Robotic laparoscopic surgery has been shown to decrease task completion time, reduce errors, and decrease training time, as compared with manual laparoscopic surgery. However, current literature has not addressed the physiologic effects, in particular muscle responses, to training with a robotic surgical system. The authors seek to determine the frequency response of electromyographic (EMG) signals of specific arm and hand muscles with training using the da Vinci Surgical System. METHODS: Seven right-handed medical students were trained in three tasks with the da Vinci Surgical System over 4 weeks. These subjects, along with eight control subjects, were tested before and after training. Electromyographic (EMG) signals were collected from four arm and hand muscles during the testing sessions, and the median EMG frequency and bandwidth were computed. RESULTS: The median frequency and frequency bandwidth both were increased after training for two of the three tasks. CONCLUSION: The results suggest that training reduces muscle fatigue as a result of faster and more deliberate movements. These changes occurred predominantly in muscles that were the dominant muscles for each task, whereas the more demanding task recruited more diverse motor units. An evaluation of the physiologic demands of robotic laparoscopic surgery using electromyography can provide us with a meaningful quantitative way to examine performance and skill acquisition.

Adult↗

Mobile in vivo camera robots provide sole visual feedback for abdominal exploration and cholecystectomy.

The use of small incisions in laparoscopy reduces patient trauma, but also limits the surgeon's ability to view and touch the surgical environment directly. These limitations generally restrict the application of laparoscopy to procedures less complex than those performed during open surgery. Although current robot-assisted laparoscopy improves the surgeon's ability to manipulate and visualize the target organs, the instruments and cameras remain fundamentally constrained by the entry incisions. This limits tool tip orientation and optimal camera placement. The current work focuses on developing a new miniature mobile in vivo adjustable-focus camera robot to provide sole visual feedback to surgeons during laparoscopic surgery. A miniature mobile camera robot was inserted through a trocar into the insufflated abdominal cavity of an anesthetized pig. The mobile robot allowed the surgeon to explore the abdominal cavity remotely and view trocar and tool insertion and placement without entry incision constraints. The surgeon then performed a cholecystectomy using the robot camera alone for visual feedback. This successful trial has demonstrated that miniature in vivo mobile robots can provide surgeons with sufficient visual feedback to perform common procedures while reducing patient trauma.

Abdomen↗

Robotic surgery training and performance: identifying objective variables for quantifying the extent of proficiency.

BACKGROUND: To understand the process of skill acquisition in robotic surgery and to allow useful real-time feedback to surgeons and trainees in future generations of robotic surgical systems, robotic surgical skills should be determined with objective variables. The aim of this study was to assess skill acquisition through a training protocol, and to identify variables for the quantification of proficiency. METHODS: Seven novice users of the da Vinci Surgical System engaged in 4 weeks of training that involved practicing three bimanual tasks with the system. Seven variables were determined for assessing speed of performance, bimanual coordination, and muscular activation. These values were compared before and after training. RESULTS: Significant improvements were observed through training in five variables. Bimanual coordination showed differences between the surgical tasks used, whereas muscular activation patterns showed better muscle use through training. The subjects also performed the surgical tasks considerably faster within the first two to three training sessions. CONCLUSIONS: The study objectively demonstrated that the novice users could learn to perform surgical tasks faster and with more consistency, better bimanual dexterity, and better muscular activity utilization. The variables examined showed great promise as objective indicators of proficiency and skill acquisition in robotic surgery.

Adult↗

Miniature robots can assist in laparoscopic cholecystectomy.

Laparoscopy reduces patient trauma but eliminates the surgeon's ability to directly view and touch the surgical environment. Although current robot-assisted laparoscopy improves the surgeon's ability to manipulate and visualize the target organs, the instruments and cameras remain constrained by the entry incision. This limits tool tip orientation and optimal camera placement. This article focuses on developing miniature in vivo robots to assist surgeons during laparoscopic surgery by providing an enhanced field of view from multiple angles and dexterous manipulators not constrained by the abdominal wall fulcrum effect. Miniature camera robots were inserted through a small incision into the insufflated abdominal cavity of an anesthetized pig. Trocar insertion and other laparoscopic tool placements were then viewed with these robotic cameras. The miniature robots provided additional camera angles that improved surgical visualization during a cholecystectomy. These successful prototype trials have demonstrated that miniature in vivo robots can provide surgeons with additional visual information that can increase procedural safety.

Animals↗

Endoscopic therapy for gastroesophageal reflux disease: can it replace antireflux surgery?

This article addresses emergent endoluminal technologies currently available for the treatment of gastroesophageal reflux disease (GERD) and compares it to the laparoscopic Nissen fundoplication. To date the mainstay of GERD therapy has been achieved with either open or laparoscopic fundoplication or life-long medical treatment. Endoluminal treatment modalities attempt to augment the gastroesophageal junction (GEJ) function by various techniques. We searched the Medline database from 1980 to 2004 for studies on endoscopic GERD techniques and laparoscopic fundoplications. Product investigators were contacted for data presented in abstract form only. Endoluminal management of GERD include using radiofrequency energy, injection of biocompatible polymers and endoluminal sutures to alter the GEJ and reduce reflux. Early results while encouraging, should be evaluated thoroughly and with caution before widespread use can be advocated. Endoscopic treatment of GERD has future promise, however, more experience and perhaps further refinement in techniques and technology must occur before widespread clinical application can be encouraged.

Animals↗

Symptomatic and physiologic outcomes after operative treatment for extraesophageal reflux.

BACKGROUND: Pharyngeal pH monitoring has recently been used to identify patients with extraesophageal symptoms induced by gastroesophageal reflux. We employed this method of acid detection to evaluate patients with respiratory symptoms prior to and after laparoscopic Nissen fundoplication to further elucidate the relationship between GERD and respiratory symptoms. METHODS: Twenty-one consecutive patients with extraesophageal symptoms thought to be caused by reflux underwent symptomatic and functional evaluation (esophageal manometry and 24-h pH monitoring with a pharyngeal probe) before and after laparoscopic Nissen fundoplication. Episodes of pharyngeal acid exposure were considered abnormal if the pH dropped below 4, occurred simultaneously with esophageal acidification, and occurred outside meal times. RESULTS: All patients had gastroesophageal reflux disease (GERD) and respiratory symptoms; nine of 15 (60%) had evidence of pharyngeal reflux preoperatively. Antireflux procedures resulted in a significant decrease in pharyngeal reflux (7.9 to 1.6 episodes/24h; p <0.05) and esophageal acid exposure (7.5% to 2.1%; p <0.05). In patients with pharyngeal reflux and complete postoperative testing, three (60%) obtained improvement of respiratory symptoms and resolution of pharyngeal reflux. In two patients with recurrent respiratory symptoms after surgery, persistent pharyngeal reflux was detected. CONCLUSION: Operative treatment of GERD is effective in controlling extraesophageal reflux, measured subjectively and objectively. Evidence of pharyngeal reflux on pH testing helps to identify which patients with respiratory symptoms will benefit from an antireflux procedure.

Cough↗

Total fundoplication is the operation of choice for patients with gastroesophageal reflux and defective peristalsis.

BACKGROUND: Partial fundoplication has traditionally been indicated for patients with gastroesophageal reflux disease (GERD) who have defective peristalsis (DP). Because partial fundoplication had been reported to be a less effective means of controlling acid reflux than total fundoplication, in 1997 we stopped performing partial fundoplication for patients with DP and switched to a floppy total fundoplication. This study analyzes the results of our new strategy and compares it to our former approach. METHODS: We performed a partial fundoplication in 39 patients with DP (distal amplitude >40% of swallows) between 1994 and 1997 and a total fundoplication in 57 patients between 1997 and 2000. Symptoms scores derived from a standard questionnaire with a scale of 0-4 manometry, and 24-h pH monitoring were completed preoperatively in 86 patients and postoperatively in 40 patients. RESULTS: Heartburn scores improved in both groups (preoperative, 2.8; postoperative, 0.65; p<0.05). Dysphagia was 1.1 preoperatively and 0.62 postoperatively (p=NS) in the partial fundoplication group and 1.2 preoperatively and 0.3 postoperatively (p<0.05) in the total fundoplication group. Furthermore, none of the patients in the total fundoplication group developed new dysphagia and none required dilatation. Distal esophageal acid exposure normalized in both groups after operative treatment (median DeMeester score:72.3 vs 11.3, p<0.05, For partial fundoplication; 57.1 vs 6.3, p<0.05, For total fundoplication). Distal esophageal amplitudes averaged 27.8 mmHg preoperatively and 35.6 mmHg (p = NS) in the partial fundoplication group, they averaged 28.2 mmHg preoperatively vs 49.0 mmHg postoperatively (p<0.005) in the total fundoplication group. Two patients with a previous partial fundoplication required a conversion to a total fundoplication. No postoperative dilation was required in either group. CONCLUSIONS: Our study shows that both a partial and a total fundoplication are effective in controlling the symptoms of GERD in patients with defective peristalsis. Dysphagia improves significantly after total fundoplication but not after partial fundoplication. Although both operations brought acid reflux to within normal limits, the effect was more pronounced with total fundoplication. Total, but not partial, fundoplication produced a significant increase in amplitude of esophageal peristalsis, which may explain the subjective improvement during deglutition. Therefore, fundoplication should be the treatment of choice in patients with GERD and defective peristalsis.

Follow-Up Studies↗

Decreased mortality from necrotizing pancreatitis.

BACKGROUND: Necrotizing pancreatitis has been associated with mortality rates of 25% to 80%. We reviewed our experience to determine whether aggressive debridement and comprehensive critical care improves survival. METHODS: The records of 989 patients with the diagnosis of pancreatitis admitted between January 1990 and September 1997 were retrospectively reviewed. Twenty-six patients required surgery for necrotizing pancreatitis and are the subjects of this review. RESULTS: Five of twenty-six patients (19%) died. For all patients, mean Ranson's score was 4.3 of 11, mean admission APACHE II score was 17.2, and mean Multiple Organ Dysfunction (MOD) score was 9.1. Poor outcome was associated with infected pancreatic necrosis (P = 0.03), elevated APACHE II score on admission (P = 0.04), and progression of MOD during the week after admission (P = 0.02). CONCLUSIONS: This review demonstrates improved survival in seriously ill patients with necrotizing pancreatitis as a result of comprehensive surgical and critical care.

Adult↗