Operative Interdisziplinarität. Extremitäten

From the perspective of trauma and orthopedic surgery interdisciplinary reconstructive surgery of the extremities encompasses different indications ranging from IIIB/Copen fractures with major segmental loss of bone and soft tissue, to arterial vessel in-jury necessitating vascular repair and to biological, plastic reconstructions following resections of musculoskeletal tumors. The interdisciplinary treatment concept including trauma-orthopedic surgery combined with vascular, plastic and neuro- as well as microsurgery has significantly decreased amputation rates and functional deficits thereby improving quality of life and long-term oncological outcome The multisdisciplinary management of both complex trauma and malignant bone/ soft tissue sarcoma of the extremity is an integral task of the surgical trauma or tumor center. Close interdisciplinary communication and expierence are the precondition for performance of a priority-adapted therapeutic strategy, low complication rates and improvement of overall prognosis.     

Efficiency of small-volume resuscitation in restoration of disturbed skeletal muscle microcirculation after soft-tissue trauma and haemorrhagic shock

Background and aims Despite advances in primary care, trauma in conjunction with shock remains the leading cause for morbidity and mortality of young adults in western countries. Herein, we report on the efficiency of small-volume resuscitation to improve compromised perfusion of traumatised skeletal muscle tissue in shock.Methods In pentobarbital anaesthetised, mechanically ventilated rats, closed soft-tissue trauma of the right hind limb was induced, followed by induction of haemorrhagic shock [mean arterial blood pressure (MAP) 40 mmHg for 1 h]. For resuscitation, animals received saline (four-times the shed blood volume/20 min), 10% hydroxyethyl starch (HES) 200/0.5 (equal to shed blood volume/5 min) or 7.2% sodium chloride/6% hydroxyethyl starch 200/0.5 (HyperHES; 10% of shed blood volume/2 min). At 2 h of resuscitation, traumatised skeletal muscle tissue was analysed by in vivo microscopy. Non-resuscitated animals served as shock controls.Results Despite incomplete restoration of systemic blood pressure, HyperHES was superior to saline, but not to HES, with respect to amelioration of nutritive perfusion. Inflammatory cell response within the traumatised skeletal muscle tissue escaped from the anti-adhesive properties of HyperHES when applied for resuscitation from hypovolaemic shock, and did not differ from values in HES-treated and saline-treated animals.Conclusion Resuscitation with HyperHES is as effective as HES in improving capillary perfusion in traumatised skeletal muscle during haemorrhagic shock. However, because values of functional capillary density in the HyperHES-treated and HES-treated animals were still markedly below those reported in traumatised skeletal muscle of normovolaemic animals, further tools are needed to enhance efficiency in treatment of local skeletal muscle tissue injury during haemorrhagic shock.The paper was presented at the International Symposium on Significance of Musculo-Skeletal Soft Tissue on Pre-Operative Planning, Surgery and Healing, 13–14 February 2003, Berlin, Germany     

Small volume hypertonic hydroxyethyl starch reduces acute microvascular dysfunction after closed soft-tissue trauma

A major pathway of closed soft-tissue injury is failure of microvascular perfusion combined with a persistently enhanced inflammatory response. We therefore tested the hypothesis that hypertonic hydroxyethyl starch (HS/HES) effectively restores microcirculation and reduces leukocyte adherence after closed soft-tissue injury. We induced closed soft-tissue injury in the hindlimbs of 14 male isoflurane-anaesthetised rats. Seven traumatised animals received 7.5% sodium chloride-6% HS/HES and seven isovolaemic 0.9% saline (NS). Six non-injured animals did not receive any additional fluid and acted as a control group. The microcirculation of the extensor digitorum longus muscle (EDL) was quantitatively analysed two hours after trauma using intravital microscopy and laser Doppler flowmetry, i.e. erythrocyte flux. Oedema was assessed by the wet-to-dry-weight ratio of the EDL. In NS-treated animals closed soft-tissue injury resulted in massive reduction of functional capillary density (FCD) and a marked increase in microvascular permeability and leukocyte-endothelial cell interaction as compared with the control group. By contrast, HS/HES was effective in restoring the FCD to 94% of values found in the control group. In addition, leukocyte rolling decreased almost to control levels and leukocyte adherence was found to be reduced by approximately 50%. Erythrocyte flux in NS-treated animals decreased to 90 +/- 8% (mean SEM), whereas values in the HS/HES group significantly increased to 137 +/- 3% compared with the baseline flux. Oedema in the HS/HES group (1.06 +/- 0.02) was significantly decreased compared with the NS-group (1.12 +/- 0.01). HS/HES effectively restores nutritive perfusion, decreases leukocyte adherence, improves endothelial integrity and attenuates oedema, thereby restricting tissue damage evolving secondary to closed soft-tissue injury. It appears to be an effective intervention, supporting nutritional blood flow by reducing trauma-induced microvascular dysfunction.     

Primary permanent arterialization of the portal vein in liver transplantation

Permanent total arterialization of the portal vein in liver transplantation has been described as a method of providing portal inflow after insufficient thrombectomy due to chronic occlusion of the portal-vein system. A specific problem is the restriction of the arterial inflow and its long-term adaptation after transplantation. We describe here the surgical techniques and clinical course of three patients who underwent portal-vein arterialization for liver transplantation. Two patients had an uneventful course. In one patient, a flow reduction by means of coil embolization of one arterial inflow branch was performed; thereafter, the patient recuperated well. Analysing the microcirculation of an arterialized graft in comparison with liver grafts with normal non-arterialized portal-vein inflow, we observed an increase in inter-sinusoidal distance and a decrease in sinusoidal red blood cell velocity. From a technical point of view, we recommend permanent portal-vein arterialization by an iliac artery graft interposition from the subdiaphragmatic aorta. The inflow to the portal vein can easily be reduced by the banding of the arterial graft interposition.     

Immediate microcirculatory derangements in skeletal muscle and periosteum after closed tibial fracture

BACKGROUND: Severe musculoskeletal soft tissue injury sustained after a closed fracture to the extremities significantly influences bone healing and determines the patient's prognosis. The present study was aimed at quantitatively assessing immediate microcirculatory changes in skeletal muscle and periosteum after standardized closed fracture. METHODS: Standardized closed fracture of the left tibia in isoflurane-anesthetized Sprague-Dawley rats (n = 14) was induced using a modified weight-drop technique. The left extensor digitorum longus (EDL) muscle (n = 7) and tibial periosteum (n = 7) were surgically exposed for in vivo fluorescence microscopy 15 minutes after fracture. Nonfractured rats (n = 14) served as controls. EDL muscle edema was determined by the ratio of wet to dry weight (EDL water content). RESULTS: Closed tibial fracture resulted in a significant reduction of functional capillary density, red blood cell velocity, and volumetric blood flow in both EDL muscle and periosteum. Microvascular diameter, leukocyte adherence, and macromolecular leakage were markedly increased, indicating trauma-induced inflammation and endothelial disintegration. EDL muscle edema was found increased significantly after fracture. CONCLUSION: This model permits for the first time direct in vivo visualization and quantification of fracture-induced microhemodynamic changes and cellular interactions within the surrounding soft tissue. It demonstrates that even simple fractures lead to profound microcirculatory disturbances in skeletal muscle and periosteum, and also at sites remote from the diaphyseal fracture site. It provides a useful approach for the development of therapeutic strategies to counteract fracture-induced microvascular dysfunction.     

Effects of early and late intravenous norepinephrine infusion on cerebral perfusion,microcirculation, brain-tissue oxygenation,and edema formation in brain-injured rats

OBJECTIVES: Reduction of cerebral perfusion during the early phase after traumatic brain injury is followed by a later phase of normal to increased perfusion. Thus, pharmacologically elevating mean arterial blood pressure with the aim of improving cerebral perfusion may exert different time-dependent effects on cortical perfusion, microcirculation, tissue oxygenation and brain edema formation after traumatic brain injury. DESIGN: Randomized, placebo-controlled trial. SETTING: Experimental laboratory at a university hospital. SUBJECTS: A total of 37 male Sprague-Dawley rats subjected to a focal cortical contusion. INTERVENTIONS: At 4 or 24 hrs after focal traumatic brain injury, mean arterial blood pressure was increased to 120 mm Hg for 90 mins by infusing norepinephrine. In rats receiving physiologic saline, mean arterial blood pressure remained unchanged. In the first series, pericontusional cortical perfusion was measured using the laser Doppler flowmetry scanning technique before injury and before, during, and after the infusion period. In a second series, intracranial and cerebral perfusion pressure and intraparenchymal perfusion and tissue oxygen measured within the contused and pericontusional cortex were recorded continuously before, during, and after norepinephrine infusion. Changes in cortical microcirculation were investigated by orthogonal polarization spectral imaging. At the end of each experiment, hemispheric swelling and water content were determined gravimetrically. MEASUREMENTS AND MAIN RESULTS: At 4 and 24 hrs after traumatic brain injury, intravenous norepinephrine significantly increased pericontusional cortical perfusion, which was also reflected by an increase in diameters and flow velocities of pericontusional arterioles and venules. Cerebral perfusion pressure and intraparenchymal perfusion and tissue oxygen were significantly increased during norepinephrine infusion at 4 and 24 hrs. Hemispheric swelling and water content showed no difference between the groups. CONCLUSIONS: After cortical impact injury, early and late intravenous norepinephrine infusion pressure-dependently increased cerebral perfusion and tissue oxygenation without aggravating or reducing brain edema formation. Future studies are warranted to determine long-term changes of short and prolonged norepinephrine-induced increases in mean arterial blood pressure and cerebral perfusion pressure.     

Image guidance in pelvic and acetabular surgery--expectations, success and limitations

During the last decade navigation techniques in pelvic and acetabular surgery have been described. Nowadays, available techniques include CT-based navigation, 2D C-arm navigation and 3D C-arm navigation. The main indication is the navigated percutaneous SI screw fixation, but acetabular screw fixations are also reported. In this article, based upon a literature review and our own clinical experiences, the indications for and limitations of navigated techniques in pelvic and acetabular surgery are described.     

Decreased cognitive functioning in patients with advanced oral squamous cell carcinoma

Cognitive impairment causes a delay in diagnosis and treatment of the various cancer entities, resulting in reduced surgical outcomes and patient survival. However, no investigations have been carried out as to whether an association exists between cognitive functioning and tumour size in patients with oral squamous cell carcinoma (OSCC). In this study, 46 patients with OSCC were evaluated by using a screening test for dementia, consisting of a combination of the mini-mental state examination and the clock test (81% sensitivity and 90% specificity). Test scores were correlated with tumour size according to the TNM staging system, which was categorized as being either limited (T1, T2; n=24) or advanced (T3, T4; n=22). No difference in age (P=0.172), sex (P=0.330), the percentage of drinkers (P=0.090) or the percentage of smokers (P=0.484) was evident between the groups. Patients with advanced tumour size scored significantly lower (median 5.5 of 9 possible points) when compared with those having tumours of a limited size (median 9 of 9 possible points; P=0.005). The median score of patients with T3/T4 tumours suggested the need for comprehensive neuropsychological evaluations for dementia. In conclusion, this study has demonstrated the correlation of reduced cognitive functioning in patients with advanced OSCC. As a consequence, instructions for the identification of early signs and of symptoms of oral cancer are strongly recommended for relatives and nursing staff of patients with cognitive impairment. Such patients might need immediate treatment for oral cancer but might not be able to understand the significance of their symptoms and therefore present late, often too late.     

Thiel embalming technique: a valuable method for microvascular exercise and teaching of flap raising

Because of its high requirements on dexterity and microsurgical skills and the need of complete understanding of flap anatomy, microvascular free flap transfer belongs to the most demanding surgical procedures. Therefore, courses for flap raising and microvascular exercise are considered a prerequisite to prepare for clinical practise. To achieve teaching conditions as realistic as possible we used a novel cadaver embalming method enabling tissue dissection comparable to the living body. Thirty cadavers which were offered to us by the Institute of Anatomy for the purpose of running flap raising courses were embalmed in the technique described by Thiel. On each cadaver, nine free flaps were dissected according to a structured protocol by each course participant and afterwards used for microvascular exercise. The conservation of fine vascular structures and the suitability of the embalmed tissue for microvascular suturing were observed and photographically documented. The Thiel embalming technique provided flap raising procedures to be performed under realistic conditions similar to the living body. Vessels and nerves could be exposed and dissected up to a diameter of 1 mm and allowed for microvascular suturing even after weeks like fresh specimens. The Thiel embalming method is a unique technique and ideally suited to teach flap raising and microvascular suturing on human material.