[Measures for allogeneic blood conservation in surgery]

The aim of all efforts to reduce the need of allogeneic blood transfusions is to avoid associated risks. There should particularly be a favourable effect according to the rate of transfusion-transmitted virus infections and immunological side-effects. The acceptance of an individually adjusted lowest haematocrit level and the minimisation of intra-operative blood loss by the application of optimal surgical techniques are among the most essential strategies to reduce or even avoid allogeneic blood transfusions. In addition the following interventions are generally accepted: Preoperative autologous blood donation, where appropriate supported by erythropoietin Preoperative haemodilution, where appropriate supported by erythropoietin Intra- and postoperative blood salvage Topical or systemic pharmacologic interventions to accelerate haemostasis Controlled hypotension Efficacy and indication of the different measures always depend on the individual circumstances of the specific patient. Therefore one should develop an individual approach for every case. In this context the most important subjects are an optimal coordination and if required an appropriate combination of the discussed methods. Algorithms which preoperatively allow approximate calculation of expected transfusion need may be a meaningful tool to facilitate blood conservation planning. However, at the same time one must consider that all strategies to reduce allogeneic transfusion needs are also associated with particular risks. Therefore one has to weigh carefully the pros and cons prior to their application, including the possible alternative of allogeneic transfusion in one's decision making process.

Correlation of bone defect dimensions with healing outcome one year after apical surgery

This clinical study prospectively evaluated the healing outcome 1 year after apical surgery in relation to bony crypt dimensions measured intraoperatively. The study cohort included 183 teeth in an equal number of patients. For statistical analysis, results were dichotomized (healed versus non-healed cases). The overall success rate was 83% (healed cases). Healing outcome was not significantly related to the level and height of the facial bone plate. In contrast, a significant difference was found for the mean size of the bony crypt when healed cases (395 mm(3)) were compared with non-healed cases (554 mm(3)). In addition, healed cases had a significantly shorter mean distance (4.30 mm) from the facial bone surface to the root canal (horizontal access) compared with non-healed cases (5.13 mm). With logistic regression, however, the only parameter found to be significantly related to healing outcome was the length of the access window to the bony crypt.

Clinical and radiographic assessment of various predictors for healing outcome 1 year after periapical surgery

This clinical study prospectively evaluated the influence of various predictors on healing outcome 1 year after periapical surgery. The study cohort included 194 teeth in an equal number of patients. Three teeth were lost for the follow-up (1.5% drop-out rate). Clinical and radiographic measures were used to determine the healing outcome. For statistical analysis, results were dichotomized (healed versus nonhealed). The overall success rate was 83.8% (healed cases). The only individual predictors to prove significant for the outcome were pain at initial examination (p=0.030) and other clinical signs or symptoms at initial examination (p=0.042), meaning that such teeth had lower healing rates 1 year after periapical surgery compared with teeth without such signs or symptoms. Logistic regression revealed that pain at initial examination (odds ratio=2.59, confidence interval=1.2-5.6, p=0.04) was the only predictor reaching significance. Several predictors almost reached statistical significance: lesion size (p=0.06), retrofilling material (p=0.06), and postoperative healing course (p=0.06).

Pain and swelling after periapical surgery related to oral hygiene and smoking

OBJECTIVES: To evaluate pain and swelling during the first week after periapical surgery and its relation to patient age, gender, oral hygiene, and smoking. STUDY DESIGN: One hundred two patients (31 men and 71 women) with a mean age of 40.2 years underwent periapical surgery. Age, gender, and oral hygiene and cigarette smoking before and during the postoperative course were noted. Pain and swelling scores were recorded on a descriptive 4-point scale at 2, 6, and 12 hours after surgery, and each day thereafter for 1 week. The data were statistically evaluated for significant differences. RESULTS: The highest intensity of pain occurred during the first 48 hours, and swelling peaked on the second postoperative day. Patient age and gender had no significant effect on postoperative symptoms (P > .05). Patients with poor oral hygiene before surgery presented greater pain and swelling during the first postsurgical hours, and smokers before surgery also suffered more pain. The number of cigarettes smoked in the postoperative period and oral hygiene after surgery had no effect on pain or inflammation (P > .05). CONCLUSIONS: Periapical surgery caused little pain and moderate swelling during the first 2 days after the intervention; these findings were more distinct in patients with poor oral hygiene before surgery and in smokers.

Benefits of cardiac surgery in octogenarians--a postoperative quality of life assessment

OBJECTIVE: Assessment of postoperative quality of life in patients over 80 years after cardiac surgery including coronary artery bypass grafting (CABG), aortic valve replacement (AVR) and combined procedures. METHODS: Quality of life of n=136 patients over 80 years at operation (82.3+/-2.1 years), undergoing isolated CABG in 61 patients (45%), isolated AVR in 34 patients (25%) and a combination of CABG and AVR in 41 patients (30%) between January 1999 and December 2003 was reviewed. Preoperatively 66.2% presented in NYHA-class III/IV or CCS-class III/IV. Mean ejection fraction (EF) was 59.5%+/-14.0 (range 25-90%). Quality of life assessment was performed via a Seattle Angina Questionnaire. Follow-up was 100% complete for a total of 890 days (69-1853 days). RESULTS: Five-year survival was 70% for the CABG group, 75% for the AVR group and 65% for the CABG/AVR group. Quality of life was remarkable in all of the three groups after surgery. Overall 97 patients (81%) were not or little disabled in their daily activity. One hundred and twelve patients (93%) were free or considerably less symptomatic. Seventy-eight patients or 65% reported to be very satisfied with their current quality of life and 112 patients (93%) felt very reassured to have continuous full access to medical treatment despite of their advanced age. CONCLUSIONS: A remarkable quality of life and important improvement in the functional status after cardiac surgery in patients over 80 paired with a satisfactory medium-term survival justify early intervention for heart disease in this age group. Therefore, referral practice for patients over 80 years for heart surgery should be handled liberally.

[Surgery for Parkinson's disease]

Surgery for Parkinson's Disease (PD) is being increasingly used. The main reason for this renewal in surgical treatment for PD is the "deep brain stimulation" (DBS) that replaced the previously used stereotactic lesions in most centers. DBS allows a focal specific electrical stimulation of basal ganglia target instead of an irreversible lesion. Mainly bilateral DBS of the nucleus subthalamicus is now an established surgical treatment for PD. But DBS of the Globus pallidus internus and of the thalamus should still be considered in selected patients. DBS is an efficient treatment for motor complication of PD that can no longer be controlled by drug treatment. Dyskinesia, bradykinesia, tremor and rigor can be improved by DBS and the medication can be reduced. It is still unclear, however, how the improvement in motor symptoms affects quality of life in the long term. Furthermore, patients with severe cognitive and psychiatric symptoms as well as patients with severe axial symptoms should not be operated since these symptoms may worsen after surgery.

rFVIIa in the treatment of persistent hemorrhage in pediatric patients on ECMO following surgery for congenital heart disease

BACKGROUND: Patients who require extracorporeal membrane oxygenation (ECMO) postsurgery for congenital heart disease (CHD) frequently experience severe bleeding episodes. Whereas recombinant-activated factor VII (rFVIIa) has proven efficacy in counteracting intractable hemorrhage in various scenarios, its use in patients on ECMO is limited by the increased risk for thrombotic events. METHODS: Between December 2004 and January 2006, ECMO was used in 10 pediatric patients following cardiac surgery, of whom seven were treated with rFVIIa because of intractable hemorrhage. Their medical records were reviewed with respect to variations in chest tube output and transfusion requirements, occlusion of or thrombus formation in the ECMO circuit and the occurrence of thromboembolic events. Outcome and rate of ECMO circuit occlusion were compared with historic controls. RESULTS: Three patients died, and four survived (none of the deaths was attributable to thrombus formation or bleeding). All patients were treated with aprotinin prior to and during rFVIIa therapy. Two patients developed an occlusion of the oxygenator, one after receiving co-medication with a FXIII concentrate, another after RBC transfusion in the ECMO system. In two patients, thrombus formation was observed in the ECMO system on inspection after discontinuation. Thromboembolic events were not observed. CONCLUSIONS: Recombinant-activated factor VII in a median dosage of 90 microg.kg(-1) was used in seven pediatric patients on ECMO. Rates of ECMO system occlusions and mortality did not differ from historic controls. Neither the reduction of chest tube output nor the blood product transfusion requirements did reach statistical significance.

[Does cataract surgery increase the risk of exudative age-related macular degeneration? Results from a large retrospective case-control study]

BACKGROUND: Many epidemiological studies indicate a positive correlation between cataract surgery and the subsequent progression of age-related macular degeneration (AMD). Such a correlation would have far-reaching consequences. However, in epidemiological studies it is difficult to determine the significance of a single risk factor, such as cataract surgery. PATIENTS AND METHODS: We performed a retrospective case-control study of patients with new onset exudative age-related macular degeneration to determine if cataract surgery was a predisposing factor. A total of 1496 eyes were included in the study: 984 cases with new onset of exudative AMD and 512 control eyes with early signs of age-related maculopathy. Lens status (phakic or pseudophakic) was determined for each eye. RESULTS: There was no significant difference in lens status between study and control group (227/984 [23.1 %] vs. 112/512 [21.8 %] pseudophakic, p = 0.6487; OR = 1.071; 95 % CI = 0.8284-1.384). In cases with bilateral pseudophakia (n = 64) no statistically significant difference of the interval between cataract surgery in either eye and the onset of exudative AMD in the study eye was found (225.9 +/- 170.4 vs. 209.9 +/- 158.2 weeks, p = 0.27). CONCLUSIONS: Our results provide evidence that cataract surgery is not a major risk factor for the development of exudative AMD.

Impact of a self-developed planning and self-constructed navigation system on skull base surgery: 10 years experience

CONCLUSION: Our self-developed planning and navigation system has proven its capacity for accurate surgery on the anterior and lateral skull base. With the incorporation of augmented reality, image-guided surgery will evolve into 'information-guided surgery'. OBJECTIVE: Microscopic or endoscopic skull base surgery is technically demanding and its outcome has a great impact on a patient's quality of life. The goal of the project was aimed at developing and evaluating enabling navigation surgery tools for simulation, planning, training, education, and performance. This clinically applied technological research was complemented by a series of patients (n=406) who were treated by anterior and lateral skull base procedures between 1997 and 2006. MATERIALS AND METHODS: Optical tracking technology was used for positional sensing of instruments. A newly designed dynamic reference base with specific registration techniques using fine needle pointer or ultrasound enables the surgeon to work with a target error of < 1 mm. An automatic registration assessment method, which provides the user with a color-coded fused representation of CT and MR images, indicates to the surgeon the location and extent of registration (in)accuracy. Integration of a small tracker camera mounted directly on the microscope permits an advantageous ergonomic way of working in the operating room. Additionally, guidance information (augmented reality) from multimodal datasets (CT, MRI, angiography) can be overlaid directly onto the surgical microscope view. The virtual simulator as a training tool in endonasal and otological skull base surgery provides an understanding of the anatomy as well as preoperative practice using real patient data. RESULTS: Using our navigation system, no major complications occurred in spite of the fact that the series included difficult skull base procedures. An improved quality in the surgical outcome was identified compared with our control group without navigation and compared with the literature. The surgical time consumption was reduced and more minimally invasive approaches were possible. According to the participants' questionnaires, the educational effect of the virtual simulator in our residency program received a high ranking.

A new system for computer-aided preoperative planning and intraoperative navigation during corrective jaw surgery

A new system for computer-aided corrective surgery of the jaws has been developed and introduced clinically. It combines three-dimensional (3-D) surgical planning with conventional dental occlusion planning. The developed software allows simulating the surgical correction on virtual 3-D models of the facial skeleton generated from computed tomography (CT) scans. Surgery planning and simulation include dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and segment repositioning. By coupling the software with a tracking system and with the help of a special registration procedure, we are able to acquire dental occlusion plans from plaster model mounts. Upon completion of the surgical plan, the setup is used to manufacture positioning splints for intraoperative guidance. The system provides further intraoperative assistance with the help of a display showing jaw positions and 3-D positioning guides updated in real time during the surgical procedure. The proposed approach offers the advantages of 3-D visualization and tracking technology without sacrificing long-proven cast-based techniques for dental occlusion evaluation. The system has been applied on one patient. Throughout this procedure, we have experienced improved assessment of pathology, increased precision, and augmented control.

Electroencephalographic changes after pediatric cardiac surgery with cardiopulmonary bypass: is slow wave activity unfavorable?

Pediatric cardiac surgery with cardiopulmonary bypass (CPB) is frequently associated with neurologic deficits. We describe the postoperative EEG changes, assess their possible causes, and evaluate their relevance to neurologic outcome. Thirty-one children and five neonates with congenital heart disease were included. EEG recording started after intubation and continued until 22-96 h after CPB. In addition to conventional analysis, spectral analysis was performed for occipital and frontal electrodes, and differences between pre- and postoperative delta power (delta-deltaP) were calculated. Maximum values of occipital delta-deltaP that occurred within 48 h after CPB were correlated with clinical variables and with perioperative markers of oxidative stress and inflammation. Occipital delta-deltaP correlated with frontal delta-deltaP, and maximum delta-deltaP correlated with conventional rating. Distinct rise of deltaP was detected in 18 of 21 children without any acute or long-term neurologic deficits but only in five of 10 children with temporary or permanent neurologic deficits. Furthermore, maximally registered delta-deltaP was inversely associated with duration of CPB and postoperative ventilation. Maximal delta-deltaP was also inversely associated with the loss of plasma ascorbate (as an index of oxidative stress) and plasma levels of IL-6 and IL-8. Slow wave activity frequently occurs within 48 h after CPB. However, our data do not support the notion that EEG slowing is associated with adverse neurologic outcome. This is supported by the fact that EEG slowing was associated with less oxido-inflammatory stress.