Biomedical subjects

Ronald Mårvik

Publications and source records attributed to Ronald Mårvik.

5 recordsLinked to original sources

PubMed2006

Diagnosis and treatment of gastric heterotopic pancreas.

BACKGROUND: Heterotopic pancreas (HP) in the stomach can be difficult to diagnose and there are many treatment options. The aim of this article is to review the contemporary diagnosis of and treatment options for HP in the stomach. METHODS: We undertook a retrospective review of patients with the diagnosis heterotopic pancreas registered at St. Olavs University Hospital in Trondheim from 1990 to 2002. We report on clinical findings, provide a histological review, and summarize the literature with particular emphasis on the diagnosis and treatment of HP in the stomach. RESULTS: We found 32 cases, most of them in the stomach and the small intestine. Sixteen patients were symptomatic. A histological examination showed that most of the tumors were submucosal and had the appearance of normal pancreas tissue. CONCLUSION: Gastric HP is not an uncommon diagnosis compared with many other gastric tumors and should more often be considered as a differential diagnosis. Symptom correlation is not always easy to determine, but symptom relief after treatment is well established. An endoscopic ultrasound examination may help when screening patients for extended biopsy and in deciding on which type of operation is to be performed. When treated, minimally invasive techniques should be applied.

Adult↗

PubMed2006

Are cold light sources really cold?

BACKGROUND: A fiber optic light source is the central part of endoscopic surgery. However, the light generation process causes heat transmission from a source to tip of a scope. In this study, we measured the amount of heating and pathologic effects of direct contact with the tip of scopes on the small bowel in an experimental set-up. MATERIALS AND METHODS: Temperature measurements were performed at the tip of 4 different scopes (Aesculap, Olympus, Karl Storz, and Richard Wolf), which were connected to either of 3 different xenon light sources (Olympus, Richard Wolf, Karl Storz). Temperatures at the outlet of light sources and the tip of fiber optic cables were measured as well. Tissue samples from the small bowel of a pig were obtained after exposing them to direct contact with the tip of the scopes or the fiber optic cable. RESULTS: The temperature measurements at the tip of the scopes varied between 60 degrees C and 100 degrees C (Celsius). The temperatures showed a wide variation according to the type of light source and fiber optic cable the scopes were connected to. The average temperature at the outlet of the light sources and the tip of fiber optic cables was 750 degrees C and 250 degrees C, respectively. The microscopic scores of the small bowel injury induced by exposition to the heat at the tip of the scopes were significantly high after 5 seconds of contact. Direct contact of the tip of the fiber optic cable caused total carbonization in the wall of the small bowel. CONCLUSION: Direct contact of the tip of the scope with small bowel may cause functional and cytologic injury even after short durations of exposure. Therefore, we do not recommend direct contact of scopes with the intra-abdominal organs to avoid heat injuries. In addition, this study also emphasizes the variation in heat generation at the tip of the scopes when used with a mismatching light source and fiber optic cable.

Animals↗

PubMed2005

Clinical evaluation of a new ultrasonic Doppler instrument (SonoDoppler) for the detection of blood flow during laparoscopic procedures.

Complications may be avoided by exactly clarifying the structures in the operative field during laparoscopic surgery. We aimed to study the efficiency of a new ultrasonic Doppler device, SonoDoppler, which offers an easy and efficient way of mapping the anatomy. The design of the study was prospective, open observational and carried out on a sample of 51 patients who were operated on in four hospitals. The surgeons were asked to identify a common hepatic artery, cystic artery and portal vein during a laparoscopic cholecystectomy, and corresponding structures during other laparoscopic procedures using the SonoDoppler, instrument. Total operation time (skin-to-skin) and duration of the SonoDoppler, use were measured. The main outcome measures were gain of additional safety and clinical value. A number of evaluations concerning the ergonomics, functionality and interactions with other instruments were also carried out. The SonoDoppler, instrument has the potential to help to assess and clarify the anatomy during laparoscopic procedures. Its use can be advocated not only for inexperienced surgeons, to help them map the vessels during surgery, but also for experienced surgeons during complicated cases and advanced procedures.

Journal Article↗

PubMed2004

[3-D navigation in laparoscopic surgery].

BACKGROUND: The main drawback with the laparoscopic approach is that the surgeon lacks the possibility to palpate vessels, tumours and organs during surgery. Furthermore, the laparoscope only provides a surface view of organs. There is a need for more advanced visualization that enhances the view to include information below the surface of the organs when the procedure is planned and for control and guidance during treatment. MATERIAL AND METHODS: We propose 3-D navigation technology based on preoperatively acquired MR or CT data used in combination with a laparoscopic navigation pointer. The pointer has an attached position tracker which enables the surgeon to interactively control the display of images prior to and during surgery. RESULTS: We have used this technology during treatment of four patients with adrenal tumours. Preoperative registration of images of the patients was performed within two minutes with an average accuracy of 7.1 mm. 2-D and 3-D visualizations interactively controlled by the pointer were used both for planning and for guidance of the surgical procedures. INTERPRETATION: The pointer was a useful tool in image guidance of laparoscopic surgery in the reported cases both for planning the approach in detail and for guidance. We believe abdominal 3-D image guidance using a laparoscopic navigation pointer has a large potential for improving laparoscopic surgery, especially in cases where vessels and anatomical relations might be difficult to identify using only a laparoscope. Accordingly, this new technology will increase safety and facilitate successful laparoscopic surgery.

Adrenal Gland Neoplasms↗

PubMed2004

An experimental operating room project for advanced laparoscopic surgery.

With the challenges that the health sector now faces in accordance with readjustments and demands for increased efficiency, resource utilization, and innovation, we have initiated a project to develop the future operating room for advanced laparoscopic surgery. New hospitals are being built that contain numerous operating room theaters. To share experiences and avoid repeating the same mistakes as others, we find it suitable to build an "experimental" operating room theater where we can try out and study new equipment, logistics, and communications, and operating forms and new technology that both benefit the establishment of our hospital, as well as the establishment of other hospitals and their laparoscopic operating rooms nationally and internationally. The main goals in the project are, through research and development, to reveal information and develop technology and methods to establish more efficient and prospective patient treatment that is focused on quality. The project is deeply rooted in the established research environment in Trondheim, Norway. We will develop new integrated solutions in the laparoscopic operating unit to create a possibility to rapidly implement the results in the form of practical improvements, increased quality, and renovation in patient treatment. The goal is also that this will result in the establishment of new industry nationally.

Hospital Design and Construction↗