Helmut Sitter

Philipps-Universität Marburg, Marburg an der Lahn, Hesse, Germany

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Publications (19)48.31 Total impact

  • Article: Quality of life after stereotactic radiotherapy for meningioma: a prospective non-randomized study.
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    ABSTRACT: Stereotactic radiotherapy (SRT) is well-established in the treatment of meningiomas offering high local control with low toxicity. However, the impact of SRT on quality of life (QoL) of patients remains largely unknown. This work aimed to prospectively evaluate QoL (longitudinal analysis) during and after SRT of meningiomas. We performed a single center, one-armed, prospective non-randomized study to assess QoL before and at the end of SRT (median fraction dose: 1.8 Gy; median cumulative dose: 54.0 Gy) and furthermore biannually until 24 months after SRT with the "medical outcome study short form 36". This questionnaire evaluates 8 health parameters summarized in "physical component scale" (PCS) and "mental component scale" (MCS). Between 2005 and 2007, 67 patients were enrolled and treated with SRT. 42/52 patients underwent previous operations and 10/52 primary SRT. Complete follow-up data were available from 44 patients. Compared to the german normal population (GNP) a general decrease in the mean values of all parameters was observed. After SRT mean values still declined and 12 months after SRT all parameters normalized towards their initial values. The cohort (previous operations) had better values for MCS (p = 0.004). The cohort (primary SRT) had worse values for PCS that increased asymptotically 6 months after SRT to values of cohort (previous operations) (p = 0.054). Gender, age and tumor related symptoms did not affect QoL according to MCS and PCS (p > 0.05). Local control was 98 %. Treatment was well tolerated and no severe side effects were observed. Patients with meningiomas have an impaired QoL compared to GNP. The QoL assessment after SRT revealed three phases: "depressive phase", "recovery phase" and "normalization phase". Patients treated with primary SRT developed a stable increase of the mean values for PCS. Gender, age, applied dose, symptomatology did not affect QoL.
    Journal of Neuro-Oncology 02/2013; · 3.21 Impact Factor
  • Article: Fractionated Stereotactic Radiotherapy of Glomus Jugulare Tumors
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    ABSTRACT: Background and Purpose:For glomus jugulare tumors, the goal of treatment is microsurgical excision. To minimize postoperative neurologic deficits, stereotactic radiosurgery (SRS) was performed as an alternative treatment option. Stereotactic fractionated radiotherapy (SRT) could be a further alternative. This study aims at the assessment of local control, side effects, and quality of life (QoL). Patients and Methods:Between 1999–2005, 17 patients were treated with SRT. 11/17 underwent previous operations. 6/17 received primary SRT. Treatment was delivered by a linear accelerator with 6-MV photons. Median cumulative dose was 57.0 Gy. Local control, radiologic regression, toxicity, and symptomatology were evaluated half-yearly by clinical examination and MRI scans. QoL was assessed by Short Form-36 (SF-36). Results:Median follow-up was 40 months. Freedom from progression and overall survival for 5 years were 100% and 93.8%. Radiologic regression was seen in 5/16 cases, 11/16 patients were stable. Median tumor shrinkage was 17.9% (p = 0.14). Severe acute toxicity (grade 3–4) or any late toxicity was never seen. Main symptoms improved in 9/16 patients, 7/16 were stable. QoL was not affected in patients receiving primary SRT. Conclusion:SRT offers an additional treatment option of high efficacy with less side effects, especially in cases of large tumors, morbidity, or recurrences after incomplete resections. Hintergrund und Ziel:Standardtherapie von Glomus-jugulare-Tumoren ist die mikrochirurgische Resektion. Zur Vermeidung postoperativer neurologischer Defizite wurde die stereotaktische Radiochirurgie (SRS) als Behandlungsalternative etabliert. Die stereotaktisch-fraktionierte Radiotherapie (SRT) könnte eine weitere Alternative darstellen. Ziel dieser Studie ist die Evaluation der lokalen Kontrolle, Nebenwirkungen und Lebensqualität. Patienten und Methodik:Zwischen 1999 und 2005 wurden 17 Patienten stereotaktisch-fraktioniert bestrahlt. 11/17 waren voroperiert, 6/17 wurden primär bestrahlt. Die Bestrahlung erfolgte mit einem Linearbeschleuniger mit 6-MV-Photonen. Die mediane Gesamtdosis betrug 57,0 Gy. Die lokale Kontrolle, radiologische Regression, Toxizität und Symptomatologie wurden halbjährlich mittels klinischer Untersuchungen und MRT-Kontrollen erfasst. Die Lebensqualität wurde mit dem Fragebogen Short Form-36 (SF-36) evaluiert. Ergebnisse:Die mediane Nachbeobachtungszeit lag bei 40 Monaten. Das 5-Jahres-Gesamtüberleben betrug 93,8%, das progressionsfreie Überleben 100%. Radiologische Regression trat in 5/16 Fällen auf, in 11/16 war der Tumor kontrolliert. Die mediane Tumorschrumpfung betrug 17,9% (p = 0,14). Schwere Akuttoxizität (CTC Grad 3–4) oder jegliche Spättoxizität wurde nicht beobachtet. In 9/16 Fällen konnten die Hauptsymptome gebessert werden, in 7/16 waren sie stabil. Die Lebensqualität primär mit SRT behandelter Patienten war nicht beeinträchtigt. Schlussfolgerung:Die SRT bietet eine zusätzliche Option von hoher Effektivität mit geringer Nebenwirkungswahrscheinlichkeit. Das gilt insbesondere für große Tumoren, für morbide Patienten und im Rezidivfall nach inkompletter Resektion.
    Strahlentherapie und Onkologie 04/2012; 183(10):557-563. · 3.56 Impact Factor
  • Article: Diagnostic accuracy of magnetic resonance imaging: a prospective evaluation of patients with suspected appendicitis (diamond).
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    ABSTRACT: To show the effect of standard magnetic resonance imaging (MRI) in patients with suspected appendicitis on negative laparotomy and perforation rate. Moreover, the economic impact on hospital resources was evaluated. In all, 52 patients (21 female; mean age 44.7 years) were prospectively included in this Institutional Review Board (IRB)-approved study. Abdominal MRI including coronal inversion recovery, axial T2-weighted, and contrast-enhanced axial T1-weighted sequences was performed. MRI results were compared to final clinical outcome determined by follow-up or histopathology. Change of treatment was evaluated according to the final clinical outcome. Economic impact was evaluated by comparing the costs of MRI to the savings due to a change in treatment after MRI. Negative laparotomy and perforation rate as well as sensitivity and specificity were derived. Negative laparotomy and perforation rate were 0% (0/52) and 8% (1/13). Sensitivity and specificity for detecting acute appendicitis were 85% (11/13) and 97% (38/39). In 40% of patients therapy changed due to the MRI. The overall effect on the use of hospital resources was a net saving of €2,335. Abdominal MRI in the evaluation of patients with suspected appendicitis and equivocal clinical findings is safe, reliable, and cost-effective. It should be considered an important alternative to computed tomography.
    Journal of Magnetic Resonance Imaging 03/2012; 35(3):617-23. · 2.70 Impact Factor
  • Article: Clinical significance of histone deacetylases 1, 2, 3, and 7: HDAC2 is an independent predictor of survival in HCC.
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    ABSTRACT: Histone deacetylases (HDAC) are responsible for the transcriptional control of genes through chromatin remodeling and control tumor suppressor genes. In several tumors, their expression has been linked to clinicopathological factors and patient survival. This study investigates HDACs 1, 2, 3, and 7 expressions in hepatocellular carcinoma (HCC) and their correlation with clinical data and patient survival. Tissue microarrays of 170 surgically resected primary HCCs and adjacent uninvolved tissue were evaluated immunohistochemically for the expression of HDACs 1, 2, 3, 7, and Ki-67 and were analyzed with respect to clinicopathological data and patient survival. HDACs 1, 2, 3, and Ki-67 were expressed significantly higher in cancer cells compared to normal tissue (HDAC1: p = 0.034, HDACs 2 and 3 and Ki-67: p < 0.001), while HDAC7 expression did not differ between HCC and non-cancerous liver tissue. In tumor tissue HDACs 1-3 expression levels showed high concordance with each other, Ki-67 and tumor grade (p < 0.001). High HDAC2 expression was associated with poor survival in low-grade and early-stage tumors (p < 0.05). The expression of the HDACs 1, 2, and 3 (but not HDAC7) isoenzymes correlates with clinicopathological factors, and HDAC2 expression has an impact on patient survival.
    Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 06/2011; 459(2):129-39. · 2.49 Impact Factor
  • Article: Quality of life after brainstem cavernoma surgery in 71 patients.
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    ABSTRACT: Symptomatic patients with a brainstem cavernoma are treated surgically with increasing frequency. Generally, the patient's benefit from this difficult surgical intervention is quantified by the assessment of neurological symptoms. To document the beneficial effect of surgery in a larger patient population by assessing the postoperative quality of life (QoL). In a series of 71 surgically treated patients, a detailed neurological status was assessed by Patzold Rating and Karnofsky Performance Status Scale. Patients rated their QoL with the Short Form 36 Health Survey. To document the effect of surgery on QoL, we devised a supplementary questionnaire. The last 24 patients completed Short Form 36 Health Survey pre- and postoperatively. Karnofsky Performance Status Scale improved in 44 of 71 surgical patients (62%), remained unchanged in 19 (27%), and deteriorated in 8 (11%) individuals. Patzold Rating showed a more detailed picture of the neurological symptoms. It correlated significantly with Karnofsky Performance Status Scale, which underscores its usefulness for patients with brainstem lesions. In the Short Form 36 Health Survey score, the Mental Component Summary improved with surgery (paired test, P = .015). In addition, 58 individuals (82%) declared a clear subjective benefit of surgery. The results of this large series support the notion that microsurgical removal of a brainstem cavernoma represents an effective therapy in experienced hands and is generally associated with good clinical outcome, both neurologically and in terms of QoL.
    Neurosurgery 04/2011; 69(3):689-95. · 2.79 Impact Factor
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    Article: Reproducibility of rasterstereography for kyphotic and lordotic angles, trunk length, and trunk inclination: a reliability study.
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    ABSTRACT: Determination of reliability with 3 investigators using a collective of healthy volunteers. To determine the reliability of rasterstereography 3-dimensional back surface analysis and reconstruction of the spine in healthy test subjects. Rasterstereography has been in clinical use since 1989 for patients with scoliosis and other spinal deformities and it significantly reduces the need for otherwise indispensable radiographs. The validity of this device has previously been examined in other studies. This study was performed to evaluate the reliability of rasterstereography for clinical application in diagnostic and follow-up examinations. Fifty-one healthy volunteers were examined rasterstereographically by 3 investigators. Each investigator made a series of 3 measurements of each participant in which 8 spine parameters including kyphotic angle ICT-ITL (max.), kyphotic angle VP-ITL, kyphotic angle VP-T12, lordotic angle ITL-ILS (max.), lordotic angle ITL-DM, lordotic angle T12-DM, trunk length VP-DM and trunk inclination were measured. Cronbach alpha was calculated. The influence of high or low body mass index on the accuracy of the technique was evaluated as well. Cronbach alpha for the intratester-reliability of the kyphotic angle ICT-ITL (max.) for the 3 investigators has values between 0.921 and 0.992. The intertester-reliability for the same parameter is 0.979 (95% CI). In this study group a meaningful association between body mass index and reliability of the device was not found. The reliability revealed very good results, both for intratester and for intertester reliability. The technique is well suited for analysis of the back in standing position. The body mass index has no influence on the reproducibility.
    Spine 06/2010; 35(14):1353-8. · 2.08 Impact Factor
  • Article: Comparison of stereotactic radiosurgery and fractionated stereotactic radiotherapy of acoustic neurinomas according to 3-D tumor volume shrinkage and quality of life.
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    ABSTRACT: Stereotactic radiosurgery (SRS) and also fractionated stereotactic radiotherapy (SRT) offer high local control (LC) rates (> 90%). This study aimed to evaluate three-dimensional (3-D) tumor volume (TV) shrinkage and to assess quality of life (QoL) after SRS/SRT. From 1999 to 2005, 35/74 patients were treated with SRS, and 39/74 with SRT. Median age was 60 years. Treatment was delivered by a linear accelerator. Median single dose was 13 Gy (SRS) or 54 Gy (SRT). Patients were followed up > or = 12 months after SRS/SRT. LC and toxicity were evaluated by clinical examinations and magnetic resonance imaging. 3-D TV shrinkage was evaluated with the planning system. QoL was assessed using the questionnaire Short Form-36. Median follow-up was 50/36 months (SRS/SRT). Actuarial 5-year freedom from progression/overall survival was 88.1%/100% (SRS), and 87.5%/87.2% (SRT). TV shrinkage was 15.1%/40.7% (SRS/SRT; p = 0.01). Single dose (< 13 Gy) was the only determinant factor for TV shrinkage after SRS (p = 0.001). Age, gender, initial TV, and previous operations did not affect TV shrinkage. Acute or late toxicity (> or = grade 3) was never seen. Concerning QoL, no significant differences were observed after SRS/SRT. Previous operations and gender did not affect QoL (p > 0.05). Compared with the German normal population, patients had worse values for all domains except for mental health. TV shrinkage was significantly higher after SRT than after SRS. Main symptoms were not affected by SRS/SRT. Retrospectively, QoL was neither affected by SRS nor by SRT.
    Strahlentherapie und Onkologie 09/2009; 185(9):567-73. · 3.56 Impact Factor
  • Article: Prospective evaluation of the value of magnetic resonance imaging in suspected acute sigmoid diverticulitis.
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    ABSTRACT: The purpose of this study was to prospectively investigate patients with suspected acute colonic diverticulitis and to provide sensitivity, specificity, and interobserver agreement in a blinded trial. Fifty-five patients (29 men; 59 +/- 13 (range, 29-76) years) who reported to the emergency room with clinically suspected acute colonic diverticulitis were prospectively included in the study. All patients underwent magnetic resonance imaging scans of their abdomen before and after contrast agent administration. Two assessors blinded to all clinical, laboratory, and radiologic results evaluated the images separately. The assessors reported colonic wall thickening, segmental narrowing of the colon, presence of diverticula, pericolic fatty infiltration, ascites, and abscesses. The assessors had to diagnose or rule out acute colonic diverticulitis. Sensitivities, specificities, positive, and negative likelihood ratios were derived. To determine interobserver agreement, a Cohen's kappa coefficient was calculated. The two assessors exhibited sensitivities of more than 94 percent, specificities of 88 percent, positive likelihood ratios of more than 7.5, and negative likelihood ratios of less than 0.07. The kappa coefficient showed a significant, strong correlation between both assessors (kappa = 0.68). Magnetic resonance imaging is investigator independent and provides high sensitivity and specificity for the diagnosis of acute colonic diverticulitis.
    Diseases of the Colon & Rectum 05/2008; 51(12):1810-5. · 3.13 Impact Factor
  • Article: Fractionated stereotactic radiotherapy of glomus jugulare tumors. Local control, toxicity, symptomatology, and quality of life.
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    ABSTRACT: For glomus jugulare tumors, the goal of treatment is microsurgical excision. To minimize postoperative neurologic deficits, stereotactic radiosurgery (SRS) was performed as an alternative treatment option. Stereotactic fractionated radiotherapy (SRT) could be a further alternative. This study aims at the assessment of local control, side effects, and quality of life (QoL). Between 1999-2005, 17 patients were treated with SRT. 11/17 underwent previous operations. 6/17 received primary SRT. Treatment was delivered by a linear accelerator with 6-MV photons. Median cumulative dose was 57.0 Gy. Local control, radiologic regression, toxicity, and symptomatology were evaluated half-yearly by clinical examination and MRI scans. QoL was assessed by Short Form-36 (SF-36). Median follow-up was 40 months. Freedom from progression and overall survival for 5 years were 100% and 93.8%. Radiologic regression was seen in 5/16 cases, 11/16 patients were stable. Median tumor shrinkage was 17.9% (p=0.14). Severe acute toxicity (grade 3-4) or any late toxicity was never seen. Main symptoms improved in 9/16 patients, 7/16 were stable. QoL was not affected in patients receiving primary SRT. SRT offers an additional treatment option of high efficacy with less side effects, especially in cases of large tumors, morbidity, or recurrences after incomplete resections.
    Strahlentherapie und Onkologie 11/2007; 183(10):557-62. · 3.56 Impact Factor
  • Article: Perioperative prophylaxis with granulocyte colony-stimulating factor (G-CSF) in high-risk colorectal cancer patients for an improved recovery: A randomized, controlled trial.
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    ABSTRACT: We aimed to improve the postoperative outcome of high-risk patients (American Society of Anesthesiologists class 3 and 4) recovering from colorectal cancer surgery by using recombinant human G-CSF (filgrastim) as perioperative prophylaxis. In a double-blinded, placebo-controlled trial, 80 patients undergoing left-sided colorectal resection were randomized to filgrastim or placebo. Filgrastim (5 mug/kg) or placebo was administered in the afternoon on day -1, 0, and +1 relative to the operation. Primary endpoints were in a hierarchic order: quality of life (QoL) over time (determined at discharge, 2 and 6 months after operation with the European Organization for Research and Treatment of Cancer questionnaire) and the McPeek recovery score, which measures death and duration of stays in the intensive care unit and hospital. Predefined secondary endpoints were global QoL, subdomains of QoL, postoperative recovery, duration of stay, 6-month overall survival, complication rates, and cellular and immunologic parameters. There were no significant differences in both primary endpoints between the treatment groups. A significant improvement (P < .05) was obtained by filgrastim prophylaxis in the QoL subdomain family life /- social functioning,; thus, more patients recovered to their preoperative state (14 vs 4 with placebo) as determined by structured interviews. Duration of hospital stay (14 vs 12 days) and noninfectious complications were decreased from 8% to 3%. High-risk patients undergoing major operation for colorectal cancer profited from filgrastim prophylaxis with regard to duration of hospital stay, noninfectious complications, social QoL, and subjective recovery from operation. These endpoints, however, were secondary, and the primary endpoints (overall QoL and the McPeek index) did not show comparable benefits. A new confirmatory trial with the successful endpoints of this trial, as well as a cost analysis, will be needed to confirm the results before a general recommendation for the prophylactic use of G-CSF in high-risk cancer patients can be given.
    Surgery 05/2007; 141(4):501-10. · 3.10 Impact Factor
  • Article: Evaluation of the McPeek postoperative outcome score in three trials.
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    ABSTRACT: Postoperative outcome of patients is determined by recovery characteristics and self-reported quality of life. The first can be assessed with the McPeek score which values three aspects of recovery: mortality, postoperative critical care and duration of hospitalization. We calculated the McPeek score of 669 patients in three trials: (1) colorectal cancer surgery, (2) antihistamine/volume loading in various operations, and (3) cholecystectomy. Beforehand, the average of intensive care unit treatment and duration of hospitalization were determined for the different operations to define McPeek score points. The score was tested on reliability, validity, and sensitivity. In addition, clinical applicability was assessed in a survey. The score was reliable with similarly distributed score points in the three trials at different institutions. Inter-rater reliability was high (97% overlap). Validity was proven by moderate high correlation to convergent criteria such as complications (trial I to III r=0.43, r=0.38, r=0.60), preoperative American Society of Anesthesiologists class (ASA) (r=0.24, r=0.28, r=0.57), and age (r=0.23, r=0.32, r=0.31). The score was different between patients with and without neoplasms (P<0.001, trial II) and between elective or emergency patients (P<0.001, trial III). In a survey, investigators reported that the score was easy to assess and more comprehensive than four other scores. The McPeek score values the postoperative outcome on a nonlinear scale. A priori, the average duration of hospitalization and critical care for a specific operation has to be defined. Our validation suggests that it is a reliable, valid, sensitive, and practical instrument for outcome analysis after anesthesia and surgery.
    Langenbeck s Archives of Surgery 08/2006; 391(4):418-27. · 1.81 Impact Factor
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    Article: Lymph node metastasis in an animal model: effect of piecemeal laser surgical resection.
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    ABSTRACT: Endoscopic laser surgical resection of advanced squamous cell carcinoma (SCC) often requires division of the tumor into several pieces. It is unknown if this approach influences the incidence of regional and distant metastases. In 143 rabbits VX2 SCC was induced. Eight days later the tumor was resected by two different methods. In the first group en bloc cold steel resection was performed. In the second group piecemeal laser resection was performed. On the 51th day the animals were sacrificed and examined for lymph node and distant metastases. After piecemeal laser resection 47.7% of the animals had lymph node metastases compared to 24.6% after en bloc resection (P = 0.01). The incidence of distant metastases did not differ for the two groups. In our model narrow margin piecemeal laser resection was associated with a higher incidence of metastases compared to wide en bloc surgical resection. The exact mechanism responsible for this increase is unclear.
    Lasers in Surgery and Medicine 07/2005; 36(5):371-6. · 2.75 Impact Factor
  • Article: Assessing the site of recurrence in patients with secondary hyperparathyroidism by a simplified Casanova autograftectomy test.
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    ABSTRACT: Patients with recurrent secondary hyperparathyroidism (rSHPT) following total parathyroidectomy and autotransplantation were prospectively studied by a modified Casanova test to discriminate between the graft-bearing arm and the neck as the site of the recurrence. The test measures intact parathyroid hormone (PTH) in blood obtained from the non-graft-bearing arm before an ischemic period and from the arm bearing the parathyroid graft during an ischemic period caused by an Esmarch bandage. The aim of this study was to evaluate the time course of PTH levels during the test and to establish an abbreviated procedure. A series of 30 patients with rSHPT who were admitted for reoperative surgery between 1994 and 2002 were studied. Systemic PTH levels were determined prior to suprasystolic exclusion of the graft-bearing arm as well as 2, 4, 6, 8, 10, 20, and 30 minutes during it and at 10 minutes afterward. Results were interpreted with a simple algorithm that suggested graft-dependent recurrence (GDR) whenever PTH levels dropped by more than 50% and neck-dominated recurrence (NDR) whenever the PTH levels dropped to less than 20%. Patients were operated on accordingly. Biochemical normalization of calcium and PTH was defined as success. Altogether, 15 patients had GDR and were cured after graft explantation. All of these patients were identified within 4 minutes of starting the test. Another 12 patients had NDR and were cured by excising overlooked or supernumerary glands. PTH levels were indeterminate in three patients (10%). Clinically, NDR is likely in all of these cases, but the test results were firmly established with 100% accuracy 8 minutes after the start of the test procedure. This abbreviated form of the Casanova test is advantageous for accurately determining the site of recurrence in the presence of rSHPT. It is less time-consuming, satisfactory in an ambulatory setting, equally effective, and less invasive than the original Casanova procedure.
    World Journal of Surgery 07/2004; 28(6):583-8. · 2.36 Impact Factor
  • Article: Clinical value of parathyroid scintigraphy with technetium-99m methoxyisobutylisonitrile: discrepancies in clinical data and a systematic metaanalysis of the literature.
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    ABSTRACT: There is a considerable discrepancy in the literature concerning the sensitivity of parathyroid scintigraphy (PS) with 99mTc-MIBI. We therefore analyzed our own data and compared them to the literature in a metaanalysis. All patients who received 99mTc -MIBI scintigraphy and subsequent surgery in our department for the detection of enlarged parathyroid glands in primary (pHPT) or secondary (sHPT) hyperparathyroidism between 1991 and 1999 were included in our retrospective analysis. The results of surgery served as the gold standard. For a true positive result, the scintigraphy had to predict the exact location of parathyroid adenoma (PA) or parathyroid hyperplasia (PH). We then compared these data to the results of a nonstatistical systematic metaanalysis of the literature. Patients (178) underwent PS between 1991 and 1999; 139 were operated on and included in this study. Of these, 109 had pHPT and 30 had sHPT. The sensitivity and specificity of the PS were found to be 45%/94% for pHPT and 39%/40% for sHPT. Fifty-two studies concerning PS were included in the metaanalysis. Sensitivities reported varied from 39% to >90%. Consideration of the different possible techniques used for PS could not explain these discrepancies. Our data show that the sensitivity of PS in clinical routine may be lower than expected from the literature. Our data are consistent with other studies and with partially unpublished clinical observations from other university hospitals. We believe that a well-designed and properly conducted prospective study is necessary to evaluate the reasons for the differences observed.
    World Journal of Surgery 01/2004; 28(1):100-7. · 2.36 Impact Factor
  • Article: From clinical evidence to everyday practice: implementing findings from a cost-effectiveness analysis for endoscopic injection therapy for upper-gastrointestinal bleeding.
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    ABSTRACT: A previous upper-gastrointestinal bleeding trial showed that patients treated with repeated fibrin glue injection for upper-gastrointestinal bleeding have significantly less rebleeding than those treated with polidocanol. To analyse the cost and effectiveness of repeated fibrin glue injection and to investigate whether these results change physicians' attitudes. A retrospective random sample of five hospitals from the previous study, collection of cost identification, and follow-up data on 320 patients (155 in the polidocanol group, 165 in the fibrin glue group). An incremental cost-effectiveness analysis and comparison of outcomes was performed using chi-squared tests and Kaplan-Meier survival analysis. A survey was carried out using a questionnaire in the five hospitals on local guidelines for management of ulcer bleeding, and its results were analysed qualitatively. The measure of effectiveness is the number of prevented rebleedings. Further variables were length of hospital stay and length of intensive care unit (ICU) stay. The cost for the prevention of one additional rebleeding by repeated fibrin glue treatment amounts to 14,316 +/- 4981 euros (incremental cost-effectiveness ratio). There were no significant differences in length of stays in ICU or in hospital. The physicians did not change their management plans for patients with upper-gastrointestinal bleeding. In a survey, it was seen that other factors, such as local guidelines, attitudes towards new treatment options, and ease of handling of drugs, are more important than a result of a single study for a behavioural change of the doctors. The study was not designed prospectively to address a pharmacoeconomic question. As relevant variables (e.g. length of ICU stay) could not be reliably ascertained retrospectively, this may lead to biased estimates of the incremental cost-effectiveness ratio.
    European Journal of Gastroenterology & Hepatology 04/2003; 15(3):295-304. · 1.76 Impact Factor
  • Article: Quality of life and patient satisfaction after reoperation for primary hyperparathyroidism: analysis of long-term results.
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    ABSTRACT: Morbidity after reoperation for persistent or recurrent primary hyperparathyroidism (pHPT) is higher than after primary surgery. According to our experience, there is a contrast between postoperative normalization of laboratory parameters and the quality of life/patient satisfaction after reoperation. Therefore the aim of the study was to analyze the outcomes of reoperations in comparison to primary surgery. We evaluated the patients' reported quality of life using the SF-36 (an accepted health status assessment tool) and complete prospectively documented perioperative and follow-up data including postoperative complications. Additionally, we searched for reasons why primary surgical intervention did not succeed. In a prospective cohort study the perioperative data of 653 consecutive patients with pHPT, including 75 reoperated patients (11.5%) who underwent parathyroidectomy between 1987 and 1999, were evaluated by uni- and multivariate analysis. At a median 78 months (6-156 months) postoperatively, all patients underwent a planned follow-up that included the SF-36, physical examination, and laboratory investigations. A total of 51 reoperated patients were available for follow-up. Postoperative alleviation of symptoms or being symptom-free was reported by 70.6%. Patients after reoperation had lower SF-36 scores in all health domains postoperatively than patients after a primary operation. Of the reoperated patients, 19.6% stated that after evaluating the development of their complaints they would not consent to reoperation again. Subgroup analysis showed that 80% of patients with postoperatively persistent pHPT, 60% of those who did not observe symptom alleviation, and 44% of those after sternotomy were in the group of dissatisfied patients. Surprisingly, none of the patients with more than one reoperation, only two of the five patients with permanent recurrent laryngeal nerve injury, and only one of the four patients with persistent hypoparathyroidism were dissatisfied overall. Parathyroidectomy resulted in normocalcemia in 90.2% of the reoperated patients, with an operative morbidity of 27.4% and no mortality. After an unsuccessful operation for pHPT, patients should be treated at an expert center to avoid persistent hypercalcemia. Reoperations necessitating sternotomy should be restricted to patients with severe symptoms and signs.
    World Journal of Surgery 09/2002; 26(8):1029-36. · 2.36 Impact Factor
  • Article: Second Step: Testing—Outcome Measurements
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    ABSTRACT: Despite worldwide enthusiasm for endoscopic surgery, this new technology is now on the top of McKinlay's “product life circle curve.” Critical questions are being asked about its benefits and burdens, but the concepts applied and the methodologies used for technology assessment are in a similar position as endoscopic surgery and need a critical evaluation. (1) There are incorrect and outdated concepts for the scientific basis of surgery (surgical theory) including the basic sciences involved; biomedicine still dominates, but assessment of outcome after operations is no longer possible without clinical epidemiology and social psychology. (2) Based on an outdated scientific theory for surgery, an outdated concept of disease is still propagated. It is denoted as mechanical and is based solely on biomedicine. Human subjects are reduced to biologic machines, and outcomes measurement excludes most dimensions of functioning and well-being. To achieve a valid result for outcome measures, a hermeneutic approach must be combined with the mechanical approach. (3) Based on an outdated model of disease, the outcomes used in endoscopic surgery rely too much on traditional measures, such as mortality rate, complication rate, hospital stay, and especially an endless list of biochemical mediators. Their alterations during the perioperative period have not yet been shown to be related to clinical or hermeneutic outcomes. A new method of assessment for clinical trials in endoscopic surgery and for other surgical problems is outlined, such as for surgical infections and for surgical oncology. It includes an index of recovery and objective health status assessed by the doctor, a quality-of-life self-report by the patient, and the true endpoint concept as a critical weighting of both types of outcome by patients and doctors.
    World Journal of Surgery 01/1999; 23(8):768-780. · 2.36 Impact Factor
  • Article: Amitogenic Alginates: Key to First Clinical Application of Microencapsulation Technology
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    ABSTRACT: Microencapsulation refers to a technique of immunoisolation by coating single cells or tissue with a semipermeable membrane. By combining microencapsulation with a specific tissue culturing method, iso-, allo-, and xenotransplantation of parathyroid tissue has been achieved without immunosuppression in a long-term animal model. Prior to its clinical use, continued analyses of the alginate, used as a coating substance, determined its mitogenic properties. Purification of the commercially available alginate was achieved using patented electrophoretic procedures, resulting in an amitogenic alginate suitable for use in humans. However, this alginate exhibited entirely different physical properties. We have recently shown that isotransplanted parathyroid tissue remains vital and functioning in vivo over long periods of time using the novel amitogenic alginate. It is essential to document, whether the alginate is able to maintain immunoisolation. We have therefore assessed its in vivo function compared to the mitogenic alginate in a transgenic animal model. Altogether 600 parathyroid glands from 300 Lewis rats (donor animals) were excised and subjected to tissue culture. Thereafter they were allotransplanted to 30 parathyroidectomized Dark-Auita rats, microencapsulated with the amitogenic or the mitogenic alginate or naked, with 10 recipient animals in each group. Total serum calcium and parathyroid hormone levels were monitored continuously at weekly intervals for 30 weeks. After 26 weeks the transplant beds were excised and subjected to histologic examination. More than 6 months after allotransplantation 9 of 10 animals that had received amitogenic transplants, compared to 7 of 10 animals in the group with mitogenic microcapsules were normocalcemic. Animals that had received naked parathyroid tissue were hypocalcemic as soon as 2 weeks after allotransplantation. Correspondingly, normocalcemic animals showed vital parathyroid tissue inside the microcapsules, which were surrounded by a significantly smaller rim of fibroblasts when amitogenic alginate had been used. In addition to confirming physiologic long-term function, we were able to document for the first time that immunoisolation can also be achieved with the novel amitogenic alginate, which is suitable for clinical use.
    World Journal of Surgery 06/1998; 22(7):659-665. · 2.36 Impact Factor
  • Article: Intraoperative uitrasonography in surgery for chronic pancreatitis
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    ABSTRACT: We report our experience with intraoperative uitrasonography in 49 patients undergoing surgery for chronic pancreatitis. Among drainage procedures, there were 14 laterolateral pancreaticojejunostomies, 15 pseudocystojejunostomies, and 2 pseudocystoduodenostomies. Under the guidance of intraoperative uitrasonography, left sided partial resection of the pancreas was performed in 7 patients, whereas a Whipple-type procedure was necessary in 6 cases. All preoperatively diagnosed pseudocysts, abscess formations, and dilated pancreatic ductal systems could be easily localized with the assistance of intraoperative ultrasound. Additionally to diagnoses already made preoperatively, intraoperative uitrasonography revealed a second, smaller pseudocyst in one patient and pancreaticolithiasis in another case. However, significant assistance and comfort to the operating surgeon was provided in all cases by intraoperative ultrasound imaging. This technique, which is cost effective and minimally invasive, proved to be extremely helpful in localizing pancreatic fluid collections and the course of the pancreatic duct. It facilitates the operation by reducing tissue traumatization and operative time. In experienced hands, intraoperative uitrasonography is a reliable method and a useful adjunct to the surgeon.
    International Journal of Gastrointestinal Cancer 04/1992; 12(3):233-237.