Using apprenticeship communication flow as an ergonomic design input for future OR systems

Removing the gallbladder is a relatively simple laparoscopic operation. Tissue trauma, caused by laparoscopic cholecystectomy, is usually minimal. Misidentifying the cystic duct and artery and the common hepatic duct represents the most severe complication. However, the Critical View of Safety (CVS) technique reduces the risk of trauma, by accomplishing a safe 360° identification of the cystic duct origin at the gallbladder neck [5]. This technique is employed and trained at the Erasmus Medical Centre (EMC), Rotterdam, The Netherlands.

?This study presents the potential value of a training device which residents can use during practice. This training device must cover both user friendliness and information supply. The current information supply was studied subjectively; the CVS protocol and the users' experience were studied both objectively and subjectively. The results of these studies show that the present information supply is not satisfactory, that there is a CVS protocol which can be easily used in a training device, and that most actions defining the cystic duct during operation revert on users' experience. Therefore, it is desirable to design a new training device according to the experience of the target group and the protocols, and taking into account an optimal human‐product interaction.     

Infectious Complication in Relation to the Prophylactic Mesh Position: The PRIMA Trial Revisited

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Abdominal wall bulging after thoracic surgery, an underdiagnosed wound complication

Background

Complications after thoracic surgery have well been established, pain being the most prominent. Intercostal nerves are mixed type nerves combining motor and sensory functions. This notion is not consistent with the incidence of PTPS compared to the incidence of muscle paresis or paralysis. We would hypothesize that abdominal wall paresis or paralysis is underdiagnosed.

Methods

In our hospital, three patients developed abdominal wall paralysis after thoracic surgery and consequent nerve damage. Their cases are discussed, and a review of the literature was conducted concerning (intercostal) nerve damage on a cellular level, the anatomy of the intercostal nerve, prevention of intercostal nerve damage and surgical techniques.

Results

A cellular cascade known as Wallerian degeneration and regeneration determine whether a damaged nerve can function again. The recovery of the nerve is highly dependent on the correct function of activated Schwann cells and macrophages and is related to the amount of damage that has taken place. The anatomy of the intercostal nerve makes it susceptible to injury. Retractor placement during open thoracic surgery has shown to effect compression injury and induced mechanical deformation and damage. Given the known factors of pathophysiology and anatomy, a number of preventive measures have been tested to reduce intercostal nerve damage. Several techniques have been proposed, but the most used technique, the video-assisted thoracic surgery, has been the most effective in reducing nerve damage.

Conclusion

Abdominal wall paralysis is an underdiagnosed complication after thoracic surgery. The amount of stress on the intercostal nerves could be reduced with less invasive techniques such as the VATS technique.     

Introduction of the "Rotterdam mandibular distractor" and a biomechanical skull analysis of mandibular midline distraction

The Rotterdam mandibular distractor (RMD) is a slim, rigid, boneborne distractor for use in midline distraction of the mandible. We did a biomechanical study to compare the RMD with the Trans Mandibular Distractor-flex (TMD-flex). This included an anatomical biomechanical study that was conducted on 9 dentate human cadaveric heads using both the RMD and the TMD-flex. In the vertical plane less tipping was measured in the RMD group than in the TMD-flex group. Significantly less skeletal tipping was found in the horizontal plane in the RMD group (P=0.021). There was minimal difference in the intercondylar distance between the groups. As the amount of lateral displacement of the condyle was similar in both groups and there was less rotational movement in the RMD group, the TMD-flex would be expected to increase stress on the temporomandibular joint. As a result of the increased parallel widening in the vertical plane, more basal bone is being created and less relapse is expected using the RMD. The study design involves an in vitro anatomical model and conclusions must be drawn with care. At present clinical studies are under way and results will follow.     

Ergonomic evaluation of three new principles for mono‐incision in laparoscopic surgery

Several instruments exist for performing a simple laparoscopic procedure through one trocar‐incision. However, all of these instruments have well‐known image‐related disadvantages. In order to solve these problems three principles have been developed for which a new device was designed. The functionality of this device was evaluated with regard to four parameters: duration of task completion, number of errors, image‐stability and preference by users.

Although the differences between the three principles were small, the tests clearly showed that the problems surgeons experienced before have been significantly diminished by the new device. Time measurements showed a preference for principles 1 and 2 (1: manual zoom camera in combination with a standard grasping device; 2: laparoscope with an angle of 45° in combination with a standard grasping device), the surgeons expressing preference for principle 2. Furthermore, the new trocar system is the first device for mono‐incision in which two standard instruments (currently available on the market) are used simultaneously without enlarging the incision. Finally, each surgeon can work with the new device using the principle he/she is preferring.     

The gastrocolic trunk of Henle in pancreatic surgery: an anatomo-clinical study

From 37 peroperative and cadaver anatomical investigations, it was concluded that, in contrast to the information in common texts on anatomy and surgery, a venous gastrocolic trunk was observed in only 46% of subjects; a true bipod gastrocolic trunk of Henle was a rare (8%) phenomenon. In this respect, a variate venous anatomy at the inferior border of the neck of the pancreas, as observed in this study, must be taken into account during pancreatic surgery and radiological procedures in the pancreas. Received: December 27,1999 / Accepted: April 26, 2000     

Incisional Hernia: Early Complication of Abdominal Surgery

It has been suggested that early development of the incisional hernia is caused by perioperative factors, such as surgical technique and wound infection. Late development may implicate other factors, such as connective tissue disorders. Our objective was to establish whether incisional hernia develops early after abdominal surgery (i.e., during the first postoperative month). Patients who underwent a midline laparotomy between 1995 and 2001 and had had a computed tomography (CT) scan of the abdomen during the first postoperative month were identified retrospectively. The distance between the two rectus abdominis muscles was measured on these CT scans, after which several parameters were calculated to predict incisional hernia development. Hernia development was established clinically through chart review or, if the chart review was inconclusive, by an outpatient clinic visit. The average and maximum distances between the left and right rectus abdominis muscles were significantly larger in patients with subsequent incisional hernia development than in those without an incisional hernia (P < 0.0001). Altogether, 92% (23/25) of incisional hernia patients had a maximum distance of more than 25 mm compared to only 18% (5/28) of patients without an incisional hernia (P < 0.0001). Incisional hernia occurrence can thus be predicted by measuring the distance between the rectus abdominis muscles on a postoperative CT scan. Although an incisional hernia develops within weeks of surgery, its clinical manifestation may take years. Our results indicate perioperative factors as the main cause of incisional hernias. Therefore, incisional hernia prevention should focus on perioperative factors.     

The cervico-ocular reflex is increased in whiplash injury patients

Whiplash-associated disorders (WAD) are a major problem in the Western world, which put a formidable financial burden on modern society and which evoke an emerging debate on the true nature of their origin. To date there is no generally accepted test that allows us to diagnose WAD objectively. Because whiplash injury causes dysfunction of proprioception in the neck, we investigated the characteristics of the cervico-ocular reflex (COR) of presumptive WAD patients. These patients and age-matched healthy controls were rotated at different stimulus peak velocities in the dark while their head was fixed in space. The gain values of the COR were significantly increased in the patient population at a wide range of stimulus peak velocities with maximum difference at the lower frequencies (p = 0.037, ANOVA). Hence, although larger numbers of patients should be measured, the COR gain appears to be a parameter that may permit an objective diagnosis of WAD.