Biomedical subjects

Reimer Andresen

Publications and source records attributed to Reimer Andresen.

13 recordsLinked to original sources

PubMed2006

[Optimization of conventional X-ray images for the detection of hook of hamate fractures].

Fractures of the hook of the hamate are a rare event. The fracture cannot always be detected clinically and standard radiographs do not always provide an overlap-free image of the hook of the hamate, so that fractures can easily be overlooked. The objective of the present study was to examine if the sensitivity of detecting hamulus ossis hamati fractures can further be improved by a modified conventional radiographic projection. After dissection of the hook of the hamate on 10 cadaver hands, a fracture was produced close to the base using a surgical chisel. Conventional radiographs were then performed in four different projections (dorso-palmar, lateral, carpal-tunnel and oblique view). The oblique view was obtained in a 45 degrees supination position, slight extension and radial duction, with the tube tilted from distal to proximal by 30 degrees. An axial spiral CT was used as a reference for detection of the fracture. The highest sensitivity of the conventional radiographs, with 8/10 identified fractures (80%), was achieved by the oblique view. The carpal-tunnel view with 4/10 (40%) and the dorso-palmar projection with 3/10 (30%) were much lower. All fractures were missed in the lateral projection. If all of the conventional radiographic projections are taken into account, the sensitivity is increased to 90%. All of the fractures were reliably detected in the axial CT-image. If a hamulus ossis hamati fracture is suspected clinically, in addition to the dorso-palmar and carpal-tunnel view, the special oblique view described here should be performed as a third projection plane, while the lateral view can be dispensed with. However, even if all projections are taken into account, a negative finding in the conventional radiographic imaging does not exclude a fracture with absolute certainty. In such cases, a CT or MRI should be performed to exclude a fracture.

Cadaver↗

PubMed2005

Hook of hamate fractures: critical evaluation of different therapeutic procedures.

The treatment of choice in nondisplaced hook of hamate fractures is conservative, with lower arm splinting. Displaced fractures should be treated operatively, whereby excision of the fragment or open reduction and internal fixation are described. A hamulus ossis hamati fracture was verified in 14 patients (mean age, 42 years; range, 21 to 73 years) including 11 men and three women. In six patients (42.9 percent), conservative treatment was initiated immediately after trauma with a lower arm cast for 6 weeks, and eight patients (57.1 percent) were operated on primarily. In five patients (35.7 percent), the fragment was excised, and in three patients (21.4 percent), an open reduction and internal fixation was performed using a screw. In five of six patients treated conservatively, nonunion of the fracture with persisting clinical symptoms developed. All of those patients were treated operatively, whereby three patients underwent excision and two patients underwent screw fixation, which led to elimination of the symptoms. One patient was asymptomatic despite nonunion of the fracture and rejected surgery. All of the eight patients operated on primarily were asymptomatic 3 months after surgery. Therefore, the success rate of primary surgical treatment (eight of eight) was significantly higher compared with conservative treatment(one of six). Finally, all 14 patients were asymptomatic at late postoperative follow-up. The clinical outcome of patients with hook of hamate fractures treated conservatively was disappointing. Therefore, primary surgical treatment is recommended. In our patients, excision and open reduction and internal fixation led to comparable results.

Adult↗

PubMed2005

Therapeutic alternatives in nonunion of hamate hook fractures: personal experience in 8 patients and review of literature.

Symptomatic nonunion frequently results after conservative treatment of hamate hook fractures, emphasizing the need of appropriate surgical strategies. A retrospective analysis of 8 patients with nonunions treated by fragment excision or open reduction and internal fixation (ORIF) at 3 centers was performed. The literature was reviewed for treatment options, as bone grafting and low-intensity pulsed ultrasound. Although fragment excision is advocated as the "gold standard" in nonunion, reports on functional results are controversial, and recent anatomic and biomechanical studies of the hook challenge this opinion. In our patients, complete relief of symptoms and comparable functional results were observed after ORIF or fragment excision. Bone grafting could supplement ORIF in selected cases. Low-intensity pulsed ultrasound may evolve as a conservative treatment option. Several alternatives to hook excision are available aiming at complete anatomic and functional recovery of hamate hook nonunion. Further experience is needed before general recommendations can be formulated.

Adult↗

PubMed2004

Investigation of TRAM flap oxygenation and perfusion by near-infrared reflection spectroscopy and color-coded duplex sonography.

Near-infrared reflection spectroscopy, used experimentally for investigation of tissue hemoglobin content and oxygenation in various flaps, was tested in the pedicled transverse rectus abdominis musculocutaneous (TRAM) flap, chosen as a simple clinical model because of its well-known vascular anatomy and clinical relevance. The study intended to answer the following questions: Does the near-infrared reflection spectroscopy system used in this study measure tissue hemoglobin content and oxygenation in the superficial skin layers only, as proposed by the manufacturer? Is near-infrared reflection spectroscopy able to detect differences of tissue hemoglobin content and oxygenation in distinct zones of the TRAM flap skin before, early, and late after surgery? Does tissue hemoglobin content and oxygenation correspond to blood flow in the supplying superior epigastric artery and to clinical signs of TRAM flap perfusion and viability? In 11 patients, tissue hemoglobin content and oxygenation in the lower abdomen/TRAM flap, mastectomy skin flap, and contralateral breast were measured by a new near-infrared reflection spectroscopy system preoperatively, early postoperatively, and late postoperatively. Simultaneously, systolic peak flow in the ipsilateral superior epigastric artery was obtained by color-coded duplex sonography. Routine clinical monitoring was performed throughout the early postoperative period. Tissue hemoglobin content and oxygenation in the lower abdomen, mastectomy skin flap, and contralateral breast were similar before surgery but varied considerably between different patients. There were no significant differences among preoperative, early postoperative, and late postoperative values of tissue hemoglobin content and oxygenation in the mastectomy skin flap and contralateral breast. However, near-infrared reflection spectroscopy measurements of the TRAM flap revealed significant differences between preoperative and early postoperative values of tissue hemoglobin content and oxygenation and among zones I, II, and III early after surgery. Tissue hemoglobin content in the TRAM flap skin increased and oxygenation decreased early after surgery. Near-infrared reflection spectroscopy values corresponded to clinical signs of venous congestion predominantly in zone III. Late postoperative return of hemoglobin content and oxygenation in the TRAM flap toward preoperative values can be attributed to improved venous return by reversed flow across regurgitant valves and development of collateral circulation. Finally, there was a significant increase of systolic peak flow in the ipsilateral superior epigastric artery early after surgery. This could be related to the opening of small-caliber choke arteries between the superior and deep inferior epigastric arteries following ligation of the dominant deep inferior epigastric artery and TRAM flap transfer to the chest. Systolic peak flow returned to preoperative values late after surgery. The near-infrared reflection spectroscopy system used in this study appeared to measure hemoglobin content and oxygenation in the superficial skin layers only. Near-infrared reflection spectroscopy was able to detect differences of tissue hemoglobin content and oxygenation in the TRAM flap between preoperative and postoperative measurements and between distinct zones of the TRAM flap early postoperatively. Postoperative changes in near-infrared reflection spectroscopy values corresponded to clinical observations and blood flow in the superior epigastric artery measured by color-coded duplex sonography. Further experience is needed before near-infrared reflection spectroscopy can be advocated for routine clinical flap monitoring.

Adult↗

PubMed2003

Total wrist arthroplasty in patients with rheumatoid arthritis.

PURPOSE: After very good midterm results with an uncemented total wrist arthroplasty we evaluated the long-term outcome in a retrospective study. METHODS: Forty uncemented anatomic physiologic (APH, Implant-Service Vertreibs-GmbH, Hamburg, Germany) wrist prosthesis implantations performed in 40 patients were reviewed. The mean follow-up period was 52 months (range, 24-73 mo) and the following parameters were examined: radiographs, grip strength, range of motion, and patient's satisfaction. RESULTS: After a good short-term outcome the results deteriorated with time. The following complications occurred: 2 infections, 3 implant failures, 2 prosthesis migrations, and 33 loosenings/dislocations. All patients (39 of 40) underwent revision surgery, and severe titanium wear in the soft tissues was found intraoperatively in all cases. It became clear that even in a non-weight-bearing joint such as the wrist, titanium alloy may wear and result in tissue metallosis when used as a bearing surface of the implant. As a salvage procedure the prosthesis was removed and an arthrodesis was performed in all patients. CONCLUSIONS: Because of the deterioration of the results including an unacceptable revision rate we currently do not consider the anatomic physiologic wrist prosthesis to be a suitable implant in patients with rheumatoid arthritis.

Adult↗

PubMed2003

Poor experience with a hinged endoprosthesis (WEKO) for the metacarpophalangeal joints: all 28 prostheses removed within 2 years in 8 patients having rheumatoid arthritis.

We prospectively assessed the outcome of implanting a hinged prosthesis in destroyed metacarpophalangeal (MCP) joints (Larsen stage III-V). We implanted 28 cementless, axis-coupled total endoprostheses with hinging (WEKO prosthesis, Implant-Service GmbH, Hamburg, Germany) in 8 women (mean age 62 (47-80) years) suffering from rheumatoid arthritis. The mean follow-up period was 15 (12-18) months, and the evaluation was based on objective criteria, including joint motion, ulnar deviation of the long fingers, grip strength, radiographic migration and torsion of the prostheses, as well as the patients' subjective satisfaction. 12 months postoperatively, the mean arc of flexion was 30 (22-35) degrees, and the mean extension lag was 43 (40-48) degrees. Although no ulnar deviation was seen in 2 fingers, it was < 10 degrees in 3, between 10 degrees and 20 degrees in 7 of the fingers, and more than 20 degrees in 16. None of the patients could clench their fist firmly. We found prosthesis migration in 20 and torsion in 19 fingers. 2 years postoperatively, we had to remove all of the prostheses due to functional failure.

Aged↗

PubMed2003

Tissue oxygenation and perfusion in inferior pedicle reduction mammaplasty by near-infrared reflection spectroscopy and color-coded duplex sonography.

Near-infrared reflection spectroscopy has been used in various experimental and clinical settings to investigate tissue perfusion and oxygenation noninvasively. Its application in plastic surgery has only recently been reported. The current study used near-infrared reflection spectroscopy to monitor cutaneous microcirculation in breast skin flaps after inferior pedicle reduction mammaplasty. Thirty patients underwent bilateral reduction mammaplasty by a modified Robbins technique. Near-infrared reflection spectroscopy measurements were performed preoperatively and postoperatively at several defined positions of the breast. The reflection spectroscopy system was capable of detecting absolute values of total hemoglobin in milligrams per milliliter of tissue and tissue hemoglobin oxygen saturation in percent. Color-coded duplex sonography was used to visualize nutrient vessels of the inferior dermoglandular pedicle and to measure systolic peak flow in the arteries supplying the nipple-areola complex. Reflection spectroscopy values were examined for changes during the postoperative course. Reflection spectroscopy and duplex sonography values were analyzed for differences between patients with normal and compromised skin flap perfusion and wound healing, which was assessed clinically and by ultrasound. Preoperative reflection spectroscopy values demonstrated local, regional, and interindividual variations. Postoperatively, characteristic changes of tissue hemoglobin oxygen saturation and total hemoglobin were observed in all patients during the 2-week follow-up. Reflection spectroscopy values differed significantly between breast and nipple-areola skin. Tissue hemoglobin oxygen saturation was significantly lower, and total hemoglobin significantly higher, in patients with impaired wound healing compared with patients having normal wound healing. However, systolic peak flow in arteries of the inferior dermoglandular pedicle did not reveal differences between patients with impaired or normal wound healing of the nipple-areola complex. Near-infrared reflection spectroscopy allows the detection of hemoglobin content and oxygenation in skin flaps. Changes in tissue hemoglobin oxygen saturation and total hemoglobin reflect hemodynamic changes in skin flaps during normal and pathological wound healing. Because of considerable intraindividual and interindividual variations, trend values seem to be superior to single measurements. Although in this study, near-infrared reflection spectroscopy was capable of distinguishing between normal and impaired perfusion in skin flaps in a clinical model, its future implication may be the early detection of vascular compromise in free flaps.

Adolescent↗

PubMed2003

Hemobahn stent-grafts for treatment of femoropopliteal arterial obstructions: midterm results of a prospective trial.

PURPOSE: To report a prospective study to evaluate safety, effectiveness, and midterm patency of self-expanding stent-grafts in patients with femoropopliteal occlusive disease. MATERIALS AND METHODS: Sixty-three Hemobahn stent-grafts were used in 52 patients for treatment of medium- or long-segment (>3 cm) occlusions (82.7%) and stenoses (17.3%) of the femoropopliteal artery. The mean length of vessel segments covered was 10.9 cm +/- 5.13. Follow-up with documentation of clinical symptoms, assessment of Rutherford clinical stage of peripheral vascular disease, and color-coded duplex sonography was performed at discharge, at 1, 3, 6, 12, 18, and 24 months after implantation, and yearly thereafter. Mean follow-up duration was 23.8 months +/- 6.9 (range, 8-36 mo). Follow-up data at 12 and 24 months after treatment were available for 47 of 52 (90.4%) and 31 of 52 patients (59.6%), respectively. RESULTS: Device implantation was technically successful in all 52 patients, yielding an overall technical success rate of 100%. Procedure-related complications were observed in 12 of 52 patients (23.1%) and consisted of distal embolization (n = 4, 7.7%), minor groin hematoma (n = 7, 13.5%), and arteriovenous fistula (n = 1, 1.9%), but prolonged hospitalization and further medical, interventional, or surgical measures were not required. Stent-graft placement induced an initial improvement of the mean resting ankle-brachial index from 0.54 +/- 0.12 to 0.89 +/- 0.14 (P <.01). Primary patency rates at 12 and 24 months were 78.4% +/- 5.8 and 74.1% +/- 6.2, respectively. Primary assisted patency rates were 82.4% +/- 5.3 at 12 months and 80.3% +/- 5.6 at 24 months. Secondary patency rates at 12 and 24 months were 88.3% +/- 4.5 and 83.2% +/- 5.5, respectively. There was no significant difference (log-rank test, P >.3) between primary patency rates in patients grouped according to lengths of implanted grafts (ie, length of the treated lesions). CONCLUSION: Endovascular placement of Hemobahn stent-grafts for percutaneous treatment of medium- to long-segment high-grade stenoses and occlusions of the femoropopliteal artery is a safe procedure with excellent initial success rates and promising midterm results.

Aged↗

PubMed2003

[Outpatient primary stent-PTA in a symptomatic internal artery stenosis under protection].

In a 69-year old patient, with a symptomatic ICA stenosis a stent implantation was performed under outpatient conditions. An interdisciplinary consensus was reached that the patient was suitable for outpatient therapy. In accordance with the NASCET criteria, the patient was to be classified to the high-risk group. Within 120 days before the intervention, the following clinical symptoms had occurred: 1 TIA, 2 amaurosis fugax. In the diagnostic angiography a right postbulbar ICA stenosis of 97% was verified. The stent application and subsequent PTA were performed under protection using a filter system. The transfemoral route was always fitted with an endovascular closure system. The neck vessels were followed-up by means of colour coded duplex sonography (CCDS) on days 1, 30, 180 and 360. A contrast-medium intensified MRI was performed on the 5th day post-intervention. The implantation of the stent and PTA were done without any complications. Atheromatous plaque fragments were found in the protection system. A plaque embolism was excluded clinically and in the contrast-medium intensified MRI 5 days after the intervention. After 360 days, no restenosis was found in the CCDS, the ECA was perfused. The method presented is low in complications and shows a high success rate. If patient recruitment is adequate, this intervention can be performed on an outpatient basis.

Aged↗

PubMed2003

[Selective embolisation of posttraumatic intractable epistaxis].

Idiopathic or trauma-related nose-bleeds can in rare cases be an intractable clinical picture in which normal conservative measures fail. Further therapeutic options that can be applied are surgical vascular ligature or selective endovascular occlusion. We report on a patient who developed hemodynamically relevant epistaxis due to splanchnocranial injuries after falling from his bicycle. Spiral-CT showed a fracture of the posterior nasal septum and of the inferior nasal concha. Despite anterior and posterior nasal tamponade, anemia occurred requiring transfusion and resulting in the interdisciplinary decision to perform transcatheter embolization. Via a trans femoral incision, a 5 F Vitek catheter was introduced into the maxillary artery, and a tracker system was then advanced through the catheter supraselectively and placed in the peripheral branches of the vascular system of the sphenopalatine artery. Selective DSA clearly showed the source of bleeding to be the area supplying the sphenopalatine artery. Following documentation of the localization of bleeding, a total of six (3/30 mm) complex heliacal mini-coils were inserted. After intravascular occlusion of the sphenopalatine artery, bleeding completely stopped within a few minutes. This shows that supraselective embolization is an easily conducted, effective and low-complication method for the definitive treatment of severe posttraumatic nosebleeds, even in emergency situations.

Adolescent↗

PubMed2003

[Differential diagnosis of tailgut cyst in the case of a rectal carcinoma with presacral mass].

Cystic masses of various different origins and degrees of malignancy occur in the presacral space. Apart from benign, malignant and acute inflammatory masses, the benign lesions include a group of cystic structures to which the dysgenetic cysts belong. The tailgut cyst is a relatively rare type of gastrointestinal origin from this group. We present the case of a stenosing rectal carcinoma in which a presacral mass was additionally found, which did not get smaller compared to the rectal tumour during combined preoperative radiochemotherapy, with a lymphoma being suspected. After extirpation of the tumour, histopathological processing revealed a stenosing rectal carcinoma with an adjacent dysgenetic lesion--a tailgut cyst. Although dysgenetic lesions are rare as presacral masses, this must also be taken into account as a differential diagnosis in the various imaging procedures such as endosonography, CT and MRT when a rectal carcinoma is present.

Aged↗

PubMed2003

[Eagle syndrome: diagnostic imaging and therapy].

In the case of clinical symptoms such as dysphagia, foreign-body sensation and chronic neck or facial pain close to the ear, an Eagle syndrome should be considered in the differential diagnosis. Rational diagnostics and therapy are elucidated on the basis of four case reports. Four patients presented in the outpatients clinic with chronic complaints on chewing and a foreign-body sensation in the tonsil region. Upon specific palpation below the mandibular angle, pain radiating into the ear region intensified. In all patients, local anaesthesia with lidocaine only led to a temporary remission of symptoms. Imaging diagnostics then performed initially included cranial survey radiograms according to Clementschitsch as well as in the lateral ray path and an OPTG. An axial spiral-CT was then performed using the thin-layer technique with subsequent 3-D reconstruction. Therapy consisted of elective resection with a lateral external incision from the retromandibular. From a symptomatic point of view, the cranial survey radiograms and the OPTG revealed hypertrophic styloid processes. The geometrically corrected addition of the axial CT images produced an absolute length of 51-58 mm. The 3-D reconstruction made it possible to visualise the exact spatial orientation of the styloid processes. An ossification of the stylohyoid ligament could definitely be ruled out on the basis of the imaging procedures. After resection of the megastyloid, the patients were completely free of symptoms. Spiral-CT with subsequent 3-D reconstruction is the method of choice for exact determination of the localisation and size of a megastyloid, while cranial survey radiograms according to Clementschitsch and in the lateral ray path or an OPTG can provide initial information. The therapy of choice is considered to be resection of the megastyloid, whereby an external lateral incision has proved effective.

Adult↗

PubMed2002

[Diagnostic imaging and therapy of chondroblastoma].

The chondroblastoma is a rare lytic osseous lesion, which is typically to be found in the epiphyses of the long tubular bones. We present a case report with the differential diagnostic imaging and the surgical therapy of a chondroblastoma of the proximal tibial epiphysis. A 16-year-old male presented in the traumatological accident and emergency centre with knee pain of unclear origin that had been increasing for several months. He had no memory of any acute trauma. For further clarification, a conventional radiograph in two planes, a thin-layer CT, a multiplanar MRI before and after Gd-DTPA, and a bone scan were performed. The conventional radiological diagnostics show a smoothly circumscribed, osteolytic, eccentric lesion with marginal sclerosis, which not exceeds the epiphyseal seam of the proximal tibia. The thin-layer CT reveals an eccentric osteolysis, with a typical, narrow sclerotic seam and central calcifications. In the high-resolution MRI, the T2-weighted sequences show a locally limited, epiphyseal, lobulated lesion with a heterogeneous, in part raised signal. A further signal increase can be seen in the T1-weighted sequences after administration of Gd-DTPA. Perifocally, there is an epiphyseal edema and discrete (intraarticular fluid collection) fluid in the inner knee. In the skeletal scintigraphy, there is a strong focal and diffuse increased activity from the proximal, lateral tibial epiphysis. After the diagnosis had been rendered, curettage of the defect was performed and then, after histological confirmation of the diagnosis, completing spongiosaplasty was conducted. Taking into account the localisation and the patient's age, a virtually certain diagnosis can already be rendered using conventional imaging. A supplementary MRI or CT can be helpful for final clarification, while 3-phase skeletal scintigraphy is superfluous. The therapy of choice is curettage and subsequent filling of the defect with autologous spongiosa.

Adolescent↗