Endoscopic Image Overlay for the Targeting of Hidden Anatomy in Laparoscopic Visceral Surgery

Limitations associated with the visual information provided to surgeons during laparoscopic surgery increases the difficulty of procedures and thus, reduces clinical indications and increases training time. This work presents a novel augmented reality visualization approach that aims to improve visual data supplied for the targeting of non visible anatomical structures in laparoscopic visceral surgery. The approach aims to facilitate the localisation of hidden structures with minimal damage to surrounding structures and with minimal training requirements. The proposed augmented reality visualization approach incorporates endoscopic images overlaid with virtual 3D models of underlying critical structures in addition to targeting and depth information pertaining to targeted structures. Image overlay was achieved through the implementation of camera calibration techniques and integration of the optically tracked endoscope into an existing image guidance system for liver surgery. The approach was validated in accuracy, clinical integration and targeting experiments. Accuracy of the overlay was found to have a mean value of 3.5 mm ± 1.9 mm and 92.7% of targets within a liver phantom were successfully located laparoscopically by non trained subjects using the approach.

Predictors of short term treatment outcome in patients with achalasia following endoscopic or surgical therapy

Pneumatic balloon dilation and surgical myotomy are the most effective treatments for achalasia. While there is controversy which method is best, the aim of the current study was to identify predictors of symptom recurrence after endoscopic or surgical therapy.

TAPP or TEP? Population-based analysis of prospective data on 4,552 patients undergoing endoscopic inguinal hernia repair

Whether total extraperitoneal inguinal hernia repair (TEP) is associated with worse outcomes than transabdominal preperitoneal inguinal hernia repair (TAPP) continues to be a matter of debate. The objective of this large cohort study is to compare outcomes between patients undergoing TEP or TAPP.

Variable ECG signs of ischemia during controlled occlusion of the left and right coronary artery in humans

Infarct size (IS) increases with vascular occlusion time, area at risk for infarction, lack of collateral supply, absence of preconditioning, and myocardial demand for O2 supply. ECG S-T segment elevation is used as a measure of severity of ischemia and a surrogate for IS. This study in 50 patients with coronary artery disease undergoing a first 120-s balloon occlusion of a stenosis sought to determine whether S-T segment elevation, corrected for the above-mentioned variables, in the left coronary artery (LCA group, n = 36) is different from that in the right coronary artery (RCA group, n = 14) territory. After consideration of all known determinants of IS, particularly mass at risk and collateral supply, the LCA territory is more sensitive than the RCA region to a 2-min period of myocardial ischemia.

Therapy of basilar artery occlusion: a systematic analysis comparing intra-arterial and intravenous thrombolysis

BACKGROUND AND PURPOSE: Basilar artery occlusion (BAO) is an infrequent form of acute stroke, which invariably leads to death or long-term disability if not recanalized. A traditional recanalization approach based on historical controls and pathophysiological consideration is local intra-arterial thrombolysis (IAT) in eligible patients. This necessitates diagnostic evaluation and treatment in stroke centers equipped with an interventional neuroradiological service on a 24-hour basis, but its superiority to the technically simple intravenous thrombolysis (IVT) remains unproven. METHODS: We analyzed systematically published case series of substantial size reporting the outcome of BAO after IAT or IVT. RESULTS: In 420 BAO patients treated with IVT (76) and IAT (344), death or dependency were equally common: 78% (59 of 76) and 76% (260 of 344), respectively (P=0.82). Recanalization was achieved more frequently with IAT (225 of 344; 65%) than with IVT (40 of 76; 53%; P=0.05), but survival rates after IVT (38 of 76; 50%) and IAT (154 of 344; 45%) were equal (P=0.48). A total of 24% of patients treated with IAT and 22% treated with IVT reached good outcomes (P=0.82). Without recanalization, the likelihood of good outcome was close to nil (2%). CONCLUSIONS: Recanalization occurs in more than half of BAO patients treated with IAT or IVT, and 45% to 55% of survivors regain functional independence. Although improved therapy forms for BAO are necessary, hospitals not equipped for IAT may set up IVT protocols. The effect of IVT is probably not much different from the effect of IAT. IVT represents probably the best treatment that can be offered to victims of acute BAO in such hospitals.

Tracheal tear and tension pneumothorax complicating bronchoscopy-guided percutaneous tracheostomy

Percutaneous dilatational tracheostomy (PDT) is a frequently conducted procedure in critically ill patients. Bronchoscopic guidance of PDT is generally recommended to minimize the risk of unintentional tracheal injury. We present a case of tracheal tear and tension pneumothorax, a rare but potentially life-threatening complication, during continuously bronchoscopy-guided PDT. Sealing the large tracheal air fistula with the cuff of an endotracheal tube helped bridge time to definitive surgical repair in our patient. Bronchoscopic guidance may minimize, but cannot completely eliminate, the risk of tracheal injury during PDT.

Practical sources of error in measuring pulmonary artery occlusion pressure: a study in participants of a special intensivist training program of The Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI)

BACKGROUND: Physiological data obtained with the pulmonary artery catheter (PAC) are susceptible to errors in measurement and interpretation. Little attention has been paid to the relevance of errors in hemodynamic measurements performed in the intensive care unit (ICU). The aim of this study was to assess the errors related to the technical aspects (zeroing and reference level) and actual measurement (curve interpretation) of the pulmonary artery occlusion pressure (PAOP). METHODS: Forty-seven participants in a special ICU training program and 22 ICU nurses were tested without pre-announcement. All participants had previously been exposed to the clinical use of the method. The first task was to set up a pressure measurement system for PAC (zeroing and reference level) and the second to measure the PAOP. RESULTS: The median difference from the reference mid-axillary zero level was - 3 cm (-8 to + 9 cm) for physicians and -1 cm (-5 to + 1 cm) for nurses. The median difference from the reference PAOP was 0 mmHg (-3 to 5 mmHg) for physicians and 1 mmHg (-1 to 15 mmHg) for nurses. When PAOP values were adjusted for the differences from the reference transducer level, the median differences from the reference PAOP values were 2 mmHg (-6 to 9 mmHg) for physicians and 2 mmHg (-6 to 16 mmHg) for nurses. CONCLUSIONS: Measurement of the PAOP is susceptible to substantial error as a result of practical mistakes. Comparison of results between ICUs or practitioners is therefore not possible.

Accuracy of Preoperative Endoscopic Ultrasound (EUS) to Distinguish Between Early and Locally Advanced Esophageal Cancer in Daily Clinical Practice

Introduction: Preoperative chemoradiotherapy is generally recommended for locally advanced esophageal cancer (clinical stage T3 or T4 or nodal positive disease) but not for early cancer (clinical stage T0 to T2, N0). EUS has been described as the most accurate method to distinguish between early and locally advanced stage in several studies. Recently however, the high accuracy of EUS (90% or higher) was questioned by some investigators. This raises the issue whether the results of studies focused on EUS accuracy may be directly translated into daily clinical practice. Aim & Methods: The aim of this retrospective analysis was to assess the accuracy of preoperative EUS to distinguish between early and locally advanced esophageal cancer in daily clinical practice outside a study setting. EUS was performed by several investigators, including trainees in one university hospital. For this purpose, EUS reports and patient files (medical and surgical) including histological reports of 300 consecutive pts with esophageal tumors were reviewed. In pts with adenocarcinoma or squamous cell cancer and surgical resection without previous radio-/chemotherapy, EUS tumor staging was compared with histological diagnosis. Results: Out of the 300 consecutive pts with esophageal tumor and EUS 102 pts had esophageal surgery after EUS-staging without any radio-/chemotherapy. In 93 pts oesophageal cancer was confirmed, whereas 9 had other tumors. The mean age was 65 years (range 27-89), sex ratio female:male was 1:3.2. To distinguish between early and late tumor stage, the accuracy was 85%. The sensitivity and specificity for early cancer was 59%, and 93%, respectively. The diagnostic accuracy for local tumor spread was 90%, 90%, 68%, 69%, 89% for pT0, pT1, pT2, pT3 and pT4 lesions, respectively. The overall accuracy for T-stage was 74%. For pN-positive staging the accuracy of EUS was 73%. Conclusion: In daily clinical practice, the accuracy of EUS in assessing esophageal tumor staging is lower than in specific studies focusing on EUS accuracy. Mainly early esophageal cancer stages were overstaged. Thus, the implementation of recommendations for diagnostic work-up of esophageal cancer patients resulting from highly specific studies should consider the appropriate clinical setting.

Percutaneous endoscopic gastrostomy in children on peritoneal dialysis

OBJECTIVE: Insertion of percutaneous endoscopic gastrostomies (PEG) in patients on chronic peritoneal dialysis (PD) has been reported to be contraindicated due to an increased risk of morbidity and mortality. However, no systematic survey on this topic has yet been published. DESIGN: Retrospective multicenter study. SETTING: 23 pediatric dialysis units associated with the working group Arbeitsgemeinschaft für Pädiatrische Nephrologie (APN). DATA SOURCE: A structured questionnaire on clinical details of PD patients who had undergone PEG insertion or open gastrostomy (OG) since 1994 was distributed to all pediatric dialysis units of the APN. RESULTS: 27 PD patients (20 males) from 12 centers in whom PEG insertion was performed after Tenckhoff catheter introduction were evaluated. Age at intervention ranged from 0.25 to 10.9 years (median 1.3 years). Most patients were malnourished, with standard deviation score (SDS) for body weight between -4.2 and -0.6 (median -2.2). Major complications were early peritonitis < 7 days after PEG in 10/27 (37%) patients, episodes of fungal peritonitis in 7/27 (26%) patients, 4 cessations of PD and change to hemodialysis, and 2 associated deaths. However, in 14 patients, no such problems were encountered and, in 4 patients, early peritonitis effectively treated with intraperitoneal antibiotics was the only major complication. Thus, in 18/27 (67%) patients, PD was successfully reinitiated shortly after PEG insertion. Among all participating centers, only two OG procedures were reported during the study period, illustrating a clear preference for the PEG over the OG procedure among members of the APN. CONCLUSION: PEG insertion following PD initiation carries a high risk for fungal peritonitis and potential PD failure; however, complication rates in this largest reported series were lower than previously described. Antibiotic and antifungal prophylaxis, withholding PD for 2 - 3 days, and gastrostomy placement by an experienced endoscopy team are suggested precautions for lowering the risk of associated complications. When gastrostomy placement does not occur prior to or at the time of initiating PD, the risks and benefits of percutaneous versus open placement must be carefully weighed.

[Rehabilitation of an abraded occlusion with Procera-ZrO2 all-ceramic crowns. A case report]

The rehabilitation of a patient with advanced tooth wear by means of Procera ZrO2 ceramic crowns is described. A healthy, 60 year old patient complained about front teeth esthetics and impaired function due to reduced tooth height. He was aware of bruxism and wished full mouth rehabilitation. The clinical examination showed that tooth wear was generalized, but most teeth could be maintained in both jaws. A staged procedure was planned, starting with a splint therapy and a provisional fixed prosthesis to reestablish correct vertical dimension of occlusion (VDO) and stable occlusal contacts. The new ZrO2 material with the Procera technique was chosen to restore all teeth in both jaws, except the mandible front teeth. In the second treatment phase, crown lengthening of the maxillary front teeth was performed and one implant placed to replace a maxillary premolar. After final tooth preparation, impression taking and bite registration the ZrO2 crown-copings were scanned, processed and completed by veneering. A flat occlusal scheme with stable front teeth guidance was established. The advantage of the presented treatment is the esthetic result in combination with a material of high mechanical and biological quality.