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Dmitry Oleynikov

Publications and source records attributed to Dmitry Oleynikov.

17 recordsLinked to original sources
PubMed2006

Laparoscopic hiatal hernia repair with human acellular dermal matrix patch: our initial experience.

BACKGROUND: The laparoscopic repair of large hiatal hernia followed by an antireflux procedure is currently the gold standard therapy for gastroesophgeal reflux disease. However, it is recognized that recurrent hiatal herniation and wrap migration are major sources of operative failures in these patients. Some have described a reduction of such events with the placement of nonbiodegradable prosthetic patches over the primary cruroplasty. This prosthetic material may be associated with transesophageal and gastric erosions and a higher rate of postoperative dysphagia and chest pain when compared with simple suture cruroplasty alone. The aim of this study is to compare hiatal closure with a biodegradable patch (acellular dermal matrix) and simple suture curaplasty in patients undergoing laparoscopic antireflux surgery. METHODS: A total of 44 patients were prospectively enrolled in this study. Twenty-two consecutive patients undergoing large hiatal hernia repair (>5 cm) and fundoplication with primary suture cruroplasty only (group 1) were compared with 22 consecutive patients undergoing the same procedure with suture cruroplasty reinforced with an onlay acellular dermal matrix patch (group 2). The 2 groups were compared with regards to demographics, size of the hiatal hernia, pre- and postoperative symptom scores, pH studies, operative times, and hiatal hernia recurrence. RESULTS: Patients in both groups were well matched by age, weight, height, and size of hiatal hernia. There were similar preoperative values in esophageal manometry, 24-hour pH monitoring, and symptom scoring in both groups. Average operative time was 108 minutes in group 1 and 121 minutes in group 2. There were no major complications in either group. The median period of hospitalization was 1 day in both groups. Postoperative pH studies and symptoms score data were significantly improved in both groups. There was no significant difference in postoperative symptoms scores for dysphagia between the 2 groups. Two patients (one in each group) underwent esophageal dilatation for mild dysphagia postoperatively. In group 1, 2 patients (9%) had Nissen failure with hiatal hernia recurrences 6 months after surgery. There were no recurrences for the follow-up period in group 2. CONCLUSIONS: Our early results suggest that hiatal hernia repair reinforced with an acellular dermal matrix patch may reduce the incidence of recurrent herniation and wrap migration. In addition, the increase in postoperative dysphagia, chest pain, and esophageal erosions associated with nondegradable mesh has not been observed in those with an acellular dermal matrix patch to this point in our follow up. However, future investigation of the material for this particular application as well as longer follow-up is necessary.

Adult↗
PubMed2006

Endoluminal minirobots for transgastric peritoneoscopy.

The performance of surgeries through small incisions or natural orifices minimizes the invasiveness to the patient as compared to open procedures. However, the constraints on visual feedback and dexterity limit the scope of these procedures. Recent robotic technologies attempt to mitigate these constraints for flexible endoscopy and laparoscopy. Much of the current work in flexible endoscopy is in the development of a fully autonomous endoscope capable of providing the surgeon with better control. Advancements in laparoscopic technologies have demonstrated abilities to improve visualization and dexterity through telerobotics and in vivo robotics. The application of new robotic technologies in flexible endoscopy and laparoscopy to natural orifice surgery promises to further benefit the patient by eliminating abdominal incisions, scarring, and the pain associated with these incisions. The safety and feasibility of such robotic technology has been successfully demonstrated for natural orifice transluminal endoscopic surgery (NOTES) in animal models.

Animals↗
PubMed2006

Patients with pancreatic adenocarcinoma benefit from staging laparoscopy.

BACKGROUND: Unnecessary laparotomy in patients with advanced pancreatic cancer may both compromise the quality of life and delay the initiation of more appropriate therapy. Very often, peritoneal small liver metastases and true local status cannot be fully determined without surgery. Laparoscopy may spare laparotomy and decrease morbidity for patients with nonresectable advanced disease. The aim of this study was to determine the impact of laparoscopy in patients with potentially resectable adenocarcinoma of the pancreas. MATERIALS AND METHODS: We reviewed the records of patients undergoing pancreatic surgery at the University of Nebraska Medical Center from October 2001 to April 2005. A total of 59 patients were included in the study. All patients were staged radiographically with a high resolution helical computed tomography scan and their tumors were considered resectable. Thirty-seven patients underwent staging laparoscopy while 22 proceeded directly to laparotomy. RESULTS: Of the 37 patients who underwent laparoscopic staging, 9 (24.3%) were detected to have metastatic disease or advanced tumor; the remaining 28 (75.7%) patients with negative laparoscopy proceeded to laparotomy. Of those, 24 patients (85.7%) underwent pancreatic resection with curative intent, while 4 patients had metastatic or locally advanced disease at subsequent laparotomy which was missed on staging laparoscopy (false negative rate of 14.3%). Of the 22 patients who proceeded directly to laparotomy, 16 (72.7%) received curative Whipple resection and 6 (27.3%) were found to have advanced disease and received bypass procedures or biopsy alone. CONCLUSION: These findings suggest that staging laparoscopy is beneficial in a significant proportion of patients deemed resectable by routine noninvasive preoperative studies. We plan to add intraoperative laparoscopic ultrasound to our staging protocol in order to decrease the false negative rate.

Adenocarcinoma↗
PubMed2006

Effect of visual feedback on surgical performance using the da Vinci surgical system.

BACKGROUND: Robotic surgical systems quantify human movements in terms of position, velocity, and time span. This information can be used to objectively assess surgical skill. The aim of this study was to test the effects of three-dimensional vs. two-dimensional visualization on performance using the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA). MATERIALS AND METHODS: The movements of novice and expert surgeons were recorded using the da Vinci Surgical System for a two-handed task in two visual environments (two-dimensional and three-dimensional). Data were analyzed to investigate the effect of visual feedback on performance. RESULTS: Velocities and task completion times were significantly different for novices and experts (P < 0.05) for all velocity parameters in both visual conditions. Additionally, there was a significant difference between two-dimensional and three-dimensional times for novices (P < 0.05). Novices were idle significantly longer in two-dimensional than in three-dimensional visual input (P = 0.037), and overall, novices were idle longer than experts for both visual conditions (P = 0.001). CONCLUSION: Three-dimensional visual input allows novice surgeons to perform tasks with higher velocities, less idle time, and greater economy of motion. However, three-dimensional visual input provides no significant enhancement of performance for expert surgeons.

Feedback, Sensory↗
PubMed2006

Real-time augmented feedback benefits robotic laparoscopic training.

Robotic laparoscopic surgery has revolutionized minimally invasive surgery for treatment of abdominal pathologies. However, current training techniques rely on subjective evaluation. There is a lack of research on the type of tasks that should be used for training. Robotic surgical systems also do not currently have the ability to provide feedback to the surgeon regarding success of performing tasks. We trained medical students on three laparoscopic tasks and provided real-time feedback of performance during training. We found that real-time feedback can benefit training if the feedback provides information that is not available through other means (grip force). Subjects that received grip force feedback applied less force when the feedback was removed. Other forms of feedback (speed and relative phase) did not aid or impede training. Secondly, a relatively short training period (10 trials for each task) significantly improved most objective measures of performance. We also showed that robotic surgical performance can be quantitatively measured and evaluated. Providing grip force feedback can make the surgeon more aware of the forces being applied to delicate tissue during surgery.

Adult↗
PubMed2006

Mobile in vivo biopsy and camera robot.

A mobile in vivo biopsy robot has been developed to perform a biopsy from within the abdominal cavity while being remotely controlled. This robot provides a platform for effectively sampling tissue. The robot has been used in vivo in a porcine model to biopsy portions of the liver and mucosa layer of the bowel. After reaching the specified location, the grasper was actuated to biopsy the tissue of interest. The biopsy specimens were gathered from the grasper after robot retraction from the abdominal cavity. This paper outlines the steps towards the successful design of an in vivo biopsy robot. The clamping forces required for successful biopsy are presented and in vivo performance of this robot is addressed.

Animals↗
PubMed2005

In vivo robotic laparoscopy.

Laparoscopy reduces patient trauma but limits the surgeon's ability to view or touch the surgical environment directly. The surgeon's ability to visualize and manipulate target organs can be improved using currently available external robotic systems. However, tool tip orientation and optimal camera placement remain limited because the robot instruments and cameras are still constrained by the entry incisions. Placing a robot completely within the abdominal cavity would provide an unconstrained platform that could provide an enhanced field of view from arbitrary angles and dexterous manipulators not constrained by the abdominal wall fulcrum effect. Several in vivo robots have been developed and successfully tested in a porcine model. These in vivo robots have been used to observe trocar and tool insertions and placement, and to provide additional camera angles that improved surgical visualization. Equipped with a grasper, such robots will provide task assistance. These in vivo robots will be much less expensive than the current generation of large external robotic surgical systems and will ultimately allow a surgeon to be a remote first responder irrespective of the location of the patient.

Animals↗
PubMed2005

Toward in vivo mobility.

Today's laparoscopic tools impose severe ergonomic limitations and are constrained to only four degrees of freedom. These constraints limit the surgeon's ability to orient the tool tips arbitrarily, and can contribute to a variety of complications. Robots external to the patient have been used to aid in the manipulation of the tools and improve dexterity. However, these robots are expensive, bulky, and are used for only select procedures. In vivo robotic assistants have the potential to enhance the capabilities of the surgeon, reduce costs, and reduce patient trauma. The motion of these in vivo robots will not be constrained by the insertion incisions. Such assistants will need to attain optimal viewing angles by traversing the abdominal organs without causing trauma. This paper presents an experimental analysis of miniature in vivo robot wheels.

Humans↗
PubMed2005

Role of endoluminal techniques in treatment of gastro-esophageal reflux disease.

This chapter addresses emergent endoluminal technologies available currently for treatment of gastroesophageal reflux disease (GERD). 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 PubMed database from 1980 to 2005 for studies on endoscopic GERD techniques. Product investigators were contacted for data presented mainly in Abstract form. Endoluminal management of GERD includes using radiofrequency energy, injection of biocompatible polymers, and endoluminal sutures to alter the GEJ and reduce reflux. With currently earned and further growing experience, 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.

Biocompatible Materials↗
PubMed2004

Feasibility of robot-assisted totally intracorporeal laparoscopic ileal conduit urinary diversion: initial results of a single institutional pilot study.

OBJECTIVES: To explore the use of the da Vinci Surgical Robotic System (DSRS) to assist in the completion of totally intracorporeal laparoscopic ileal conduit urinary diversion (TLIC). METHODS: Two patients with radiation cystitis underwent TLIC procedures and another patient with bladder cancer underwent TLIC along with laparoscopic radical cystoprostatectomy at our institution. The ileal conduit urinary diversion was done totally intracorporeally using conventional laparoscopic techniques, and the DSRS was used to assist in the Bricker-type ureteroileal anastomosis. RESULTS: The 3 patients in the study included 2 men and 1 woman (mean age 73 years, range 64 to 84). The TLIC was completed intracorporeally in all 3 patients without the need for open conversion. The operative time, estimated blood loss, intraoperative decrease in hemoglobin, and time to hospital discharge for the 2 patients undergoing TLIC and the patient undergoing TLIC along with radical cystoprostatectomy was 628, 616, and 828 minutes, 50, 200, and 500 mL, 1.7, 2.8, and 5.3 g, and 5, 7, and 10 days, respectively. The median follow-up was 4.5 months (range 3.5 to 5.5). Postoperative satisfactory drainage of both kidneys was confirmed in all 3 patients at 8 weeks or later by intravenous urography or renal nuclear imaging. The serum creatinine remained stable in all 3 patients after surgery at hospital discharge. The only complication noted was postoperative ileus in the patient undergoing radical cystoprostatectomy that resolved with conservative management. CONCLUSIONS: TLIC is technically feasible and safe and can be done intracorporeally without complications. The DSRS can be successfully used to assist in the completion of TLIC. However, that each case lasted for more than 600 minutes highlights the need for further refinement in the technique. The practical application of TLIC requires improved long-term outcomes compared with open surgery, as well as a reduction in the operative time to justify the costs of robotic surgery.

Aged↗
PubMed2004

In vivo robots for laparoscopic surgery.

Laparoscopic techniques have allowed surgeons to perform operations through small incisions. However, the benefits of laparoscopy are still limited to less complex procedures because of losses in imaging and dexterity compared to conventional surgery. This project is developing miniature robots to be placed within the abdominal cavity to assist the surgeon. These remotely controlled in vivo robots provide the surgeon with an enhanced field of view from arbitrary angles as well as provide dexterous manipulators not constrained by small incisions in the abdominal wall.

Animals↗
PubMed2003

New alternatives in the management of gastroesophageal reflux disease.

BACKGROUND: To date the mainstay of surgical treatment for gastroesophageal reflux disease (GERD) has been achieved with either open or laparoscopic fundoplication. Several new treatment modalities are attempting to augment the gastroesophageal (GE) junction function by various endoscopic means. METHODS: The Medline database from 1980 to 2002 was searched for studies on endoscopic techniques for antireflux procedures. Product investigators were contacted for data presented in abstract form only. RESULTS: Recent improvements in equipment and technique with excellent long-term follow-up have made laparoscopic Nissen fundoplication the gold standard in antireflux surgery. New techniques include using radiofrequency energy, injection of silicon type polymer and using endoluminal sutures to narrow the gastroesophageal junction. Early results have encouraging aspects, but should be evaluated thoroughly and with caution before widespread use. CONCLUSIONS: Endoscopic treatment of gastroesophageal reflux has future promise. However, more experience and perhaps further improvement in techniques and technology must occur before wide application can be encouraged.

Catheter Ablation↗
PubMed2003

Clinical and pathologic response of Barrett's esophagus to laparoscopic antireflux surgery.

BACKGROUND DATA: Patients with Barrett's esophagus (BE) are frequently offered laparoscopic antireflux surgery (LARS) to treat symptoms. The effectiveness of this operation with regards to symptoms and to the evolution of the columnar-lined epithelium remains controversial. METHODS: We analyzed the course of 106 consecutive patients with BE who underwent LARS between 1994 and 2000, representing 14% of all LARS (754) performed in our institution during that period. All 106 patients agreed to clinical follow-up in 2002 at 40 months (median; range, 12-95 months). Fifty-three patients (50%) agreed to functional evaluation (manometry and 24-hour pH monitoring); 90 patients (85%) to thorough endoscopy, with appropriate biopsies and histologic evaluation to determine the status of BE. RESULTS: Heartburn improved in 94 (96%) of 98 and resolved in 69 patients (70%) after LARS. Regurgitation improved in 58 (84%) of 69 and dysphagia improved in 27 (82%) of 33. Distal esophageal acid exposure improved in 48 (91%) of 53 patients tested and returned to normal in 39 patients (74%). One patient underwent reoperation 2 days after fundoplication (gastric perforation). Preoperatively, biopsy revealed BE without dysplasia in 91 patients, BE indefinite for dysplasia in 12 patients, and low-grade dysplasia in 3 patients. Fifty-four of the 90 patients with endoscopic follow-up had short-segment BE (<3cm), and 36 had long-segment BE (>3cm) preoperatively. Postoperatively, endoscopy and pathology revealed complete regression of intestinal metaplasia (absence of any sign suggestive of BE) in 30 (55%) of 54 patients with short-segment BE but in 0 of 36 of those with long-segment BE. Among patients with complete regression, 89% of those tested with pH monitoring had normal esophageal acid exposure. This was observed in 69% of those who failed to have complete regression. One patient developed adenocarcinoma within 10 months of LARS. CONCLUSIONS: In patients with BE, LARS provides excellent control of symptoms and esophageal acid exposure. Moreover, intestinal metaplasia regressed in the majority of patients who had short-segment BE and normal pH monitoring following LARS, a fact that was, heretofore, not appreciated. LARS should be recommended to patients with BE to quell symptoms and to prevent the development of cancer.

Adult↗
PubMed2003

Does gallbladder ejection fraction predict outcome after cholecystectomy for suspected chronic acalculous gallbladder dysfunction? A systematic review.

The clinical utility of cholecystokinin-cholescintigraphy with calculation of a gallbladder ejection fraction (GBEF) in patients with suspected chronic acalculous gallbladder dysfunction (CAGD) remains controversial. It was our aim to critically evaluate the literature on the utility of the GBEF to predict outcome of patients with suspected CAGD. We performed an electronic search of the MEDLINE database for articles published between 1980 and 2002 and a manual search of references from bibliographies of identified articles. Only articles in English that concerned adults were screened. Data extracted included both qualitative and quantitative data reported on the study groups, cholescintigraphic technique, interventions, treatment outcomes, and trial methodologic characteristics. Twenty-three publications met the inclusion criteria. All were considered of poor methodologic quality. All but three studies were retrospective case series, only one was randomized, and none were adequately blinded, used adequate controls, or enrolled a sufficient number of patients. Five studies used a cut-off value for an abnormal GBEF that was different than the value used by the others, one study did not provide a cut-off value, and several did not report details of the cholescintigraphic technique (namely, the rate of cholecystokinin infusion). Studies varied in their outcome measures and the criteria for success. The overall assessment of outcome in 19 studies concluded that calculation of a GBEF was useful in patients with suspected CAGD. The low methodologic quality of the studies precluded a meta-analysis approach to the data. Use of a calculated GBEF to diagnose and predict treatment outcome in suspected CAGD has not been adequately studied. Although most studies report utility of GBEF in predicting symptom outcome after cholecystectomy in patients with suspected CAGD, quality evidence is lacking, thereby precluding a definitive recommendation regarding its use. More high quality trials are needed.

Cholecystectomy↗
PubMed2003

Measurements of the level of surgical expertise using flight path analysis from da Vinci robotic surgical system.

Laparoscopic surgical procedures require precise hand and eye coordination based on a 2-dimensional representation of 3-dimensional space. Currently, no metric exists to guide the educational process while surgeons are still on the learning curve. In this paper, we propose to identify and qualify the patterns of movements recorded from the da Vinci robotic surgical system (Intuitive Surgical, Sunnyvale CA) that are most consistent with mastery and can define levels of proficiency. We have recorded velocities and positions of complex movements made by both novice and expert surgeons using da Vinci system and performed geometric and statistical analysis of the data.

Clinical Competence↗
PubMedDate not supplied

Laryngoscopy and pharyngeal pH are complementary in the diagnosis of gastroesophageal-laryngeal reflux.

Pharyngeal pH monitoring and laryngoscopy are routinely used to diagnose gastroesophageal-laryngeal reflux as a cause of respiratory symptoms. Although their use seems intuitive, their ultimate diagnostic value is yet to be defined. We studied 10 asymptomatic (control) subjects and 76 patients with respiratory symptoms. Both patients and control subjects were given a symptom questionnaire. Each underwent direct laryngoscopy using the reflux finding score (RFS) to grade laryngeal injury, esophageal manometry, and 24-hour esophagopharyngeal pH monitoring. The patients were then classified as RFS+, if the score was greater than 7, and pharyngeal reflux (PR)+, if they had more than one episode of PR detected during pH monitoring. The most common symptoms reported by patients were hoarseness (87%), cough (53%), and heartburn (50%). Control subjects had a significantly lower RFS (2.1 vs. 9.6, P < 0.01) and fewer episodes of PR (0.2 vs. 3.4, P < 0.01), than patients. None of the control subjects had more than one episode of PR during a 24-hour period. Fifty patients (66%) were RFS+ and 26 (34%) were RFS-. Thirty-two patients (42%) were PR+ and 44 (58%) were PR-. Fifteen patients had a normal RFS and no PR (group I = RFS-/PR-). Forty patients had discordance between the laryngoscopic findings and the pH monitoring (group II = RFS-/PR+ or RFS+/PR-). Twenty-one patients had both an abnormal RFS and PR (group III = RFS+/PR+). Patients in group III had significantly higher heartburn scores and distal esophageal acid exposure. Eighty-three percent of patients in group III but only 44% in group I improved their respiratory symptoms as a result of antireflux therapy. An abnormal PR or RFS differentiates patients with laryngeal symptoms from control subjects. Agreement between PR and RFS helps establish or refute the diagnosis of gastroesophageal reflux as a cause of laryngeal symptoms. Patients who are RFS+ and PR- may have laryngeal injury from another source, whereas patients who are RFS- and PR+ may not have acid entering the larynx, despite the presence of PR. Patients who are RFS+ and PR+ have more severe gastroesophageal reflux disease and their reflux causes laryngeal damage. Laryngoscopy and pharyngeal pH monitoring should be considered complementary studies in establishing the diagnosis of laryngeal injury induced by gastroesophageal reflux. ( J GASTROINTEST SURG 2002;6:189-194.)

Case-Control Studies↗