54 resultados para general surgery
em Helda - Digital Repository of University of Helsinki
Resumo:
Breast cancer is the most common form of potentially fatal cancer in women in the Western world. Better understanding of the breast cancer disease process together with developments in treatments have led to improved survival and reduced risk of recurrence, significantly influencing the acceptance of breast reconstructions as part of breast cancer treatment. Skin-sparing mastectomy followed by immediate breast reconstruction has proved superior to other forms of breast reconstruction in terms of aesthetic outcome. However, due to the relatively recent introduction of skin-sparing mastectomy concerns on the surgical and oncological safety of the operation persist. The aim of the present study is to evaluate the surgical and oncological safety of skin-sparing mastectomy and immediate breast reconstruction in a consecutive patient series with ensuing follow-up. Subsequent aims of the study are to examine possibilities of reducing surgical complications of the operation and to assess the feasibility of sentinel node biopsy together with immediate breast reconstruction. The study population comprises a consecutive series of patients having undergone skin-sparing mastectomy followed by immediate breast reconstruction at the Helsinki University Central Hospital between 1992 and 2006. In Study I, the hospital records of 207 patients, operated between 1992 and 2001, were analyzed for surgical complications and recurrences of breast cancer during follow-up. In Study II, 60 consecutive patients were randomized into either conventional diathermy or radiofrequency coagulation groups to examine possibilities of reducing skin-flap complications. Study III consists of 62 consecutive breast cancer patients evaluated for the feasibility of sentinel node biopsy simultaneously with immediate breast reconstruction. In Study IV, hospital records were analyzed to examine local recurrence of breast cancer in a consecutive series of 146 patients with Stage I or II disease. Post-operative complications in Study I included native skin-flap necrosis (10.1%), hematoma (10.1%), anastomose thrombosis (5.3%), infection (3.4%), hernia (2.6%) and loss of one microvascular flap (0.7%). The Stage I and II patients in Study IV had a local recurrence rate of 2.7%, an isolated regional lymph node recurrence rate of 2.1% and a systemic recurrence rate of 2.7%, during a mean follow-up time of 51 months. The Stage III patients in study I had a locoregional recurrence rate of 31.3% during follow-up. Radiofrequency coagulation in Study II did not decrease skin-flap complications when compared with conventional diathermy. An increased skin-flap complication rate in Study II was associated with smoking and the type of skin incision used. In Study III, eleven patients had tumor positive sentinel nodes, nine of which were detected intraoperatively. Skin-sparing mastectomy followed by immediate breast reconstruction is a safe procedure both surgically and oncologically, especially for early stage breast cancer. Tennis racket type incision is associated with an increased skin-flap complication rate. Sentinel node biopsy with intraoperative assessment of sentinel node metastases is feasible in patients undergoing immediate breast reconstruction.
Resumo:
The adequacy of anesthesia has been studied since the introduction of balanced general anesthesia. Commercial monitors based on electroencephalographic (EEG) signal analysis have been available for monitoring the hypnotic component of anesthesia from the beginning of the 1990s. Monitors measuring the depth of anesthesia assess the cortical function of the brain, and have gained acceptance during surgical anesthesia with most of the anesthetic agents used. However, due to frequent artifacts, they are considered unsuitable for monitoring consciousness in intensive care patients. The assessment of analgesia is one of the cornerstones of general anesthesia. Prolonged surgical stress may lead to increased morbidity and delayed postoperative recovery. However, no validated monitoring method is currently available for evaluating analgesia during general anesthesia. Awareness during anesthesia is caused by an inadequate level of hypnosis. This rare but severe complication of general anesthesia may lead to marked emotional stress and possibly posttraumatic stress disorder. In the present series of studies, the incidence of awareness and recall during outpatient anesthesia was evaluated and compared with that of in inpatient anesthesia. A total of 1500 outpatients and 2343 inpatients underwent a structured interview. Clear intraoperative recollections were rare the incidence being 0.07% in outpatients and 0.13% in inpatients. No significant differences emerged between outpatients and inpatients. However, significantly smaller doses of sevoflurane were administered to outpatients with awareness than those without recollections (p<0.05). EEG artifacts in 16 brain-dead organ donors were evaluated during organ harvest surgery in a prospective, open, nonselective study. The source of the frontotemporal biosignals in brain-dead subjects was studied, and the resistance of bispectral index (BIS) and Entropy to the signal artifacts was compared. The hypothesis was that in brain-dead subjects, most of the biosignals recorded from the forehead would consist of artifacts. The original EEG was recorded and State Entropy (SE), Response Entropy (RE), and BIS were calculated and monitored during solid organ harvest. SE differed from zero (inactive EEG) in 28%, RE in 29%, and BIS in 68% of the total recording time (p<0.0001 for all). The median values during the operation were SE 0.0, RE 0.0, and BIS 3.0. In four of the 16 organ donors, EEG was not inactive, and unphysiologically distributed, nonreactive rhythmic theta activity was present in the original EEG signal. After the results from subjects with persistent residual EEG activity were excluded, SE, RE, and BIS differed from zero in 17%, 18%, and 62% of the recorded time, respectively (p<0.0001 for all). Due to various artifacts, the highest readings in all indices were recorded without neuromuscular blockade. The main sources of artifacts were electrocauterization, electromyography (EMG), 50-Hz artifact, handling of the donor, ballistocardiography, and electrocardiography. In a prospective, randomized study of 26 patients, the ability of Surgical Stress Index (SSI) to differentiate patients with two clinically different analgesic levels during shoulder surgery was evaluated. SSI values were lower in patients with an interscalene brachial plexus block than in patients without an additional plexus block. In all patients, anesthesia was maintained with desflurane, the concentration of which was targeted to maintain SE at 50. Increased blood pressure or heart rate (HR), movement, and coughing were considered signs of intraoperative nociception and treated with alfentanil. Photoplethysmographic waveforms were collected from the contralateral arm to the operated side, and SSI was calculated offline. Two minutes after skin incision, SSI was not increased in the brachial plexus block group and was lower (38 ± 13) than in the control group (58 ± 13, p<0.005). Among the controls, one minute prior to alfentanil administration, SSI value was higher than during periods of adequate antinociception, 59 ± 11 vs. 39 ± 12 (p<0.01). The total cumulative need for alfentanil was higher in controls (2.7 ± 1.2 mg) than in the brachial plexus block group (1.6 ± 0.5 mg, p=0.008). Tetanic stimulation to the ulnar region of the hand increased SSI significantly only among patients with a brachial plexus block not covering the site of stimulation. Prognostic value of EEG-derived indices was evaluated and compared with Transcranial Doppler Ultrasonography (TCD), serum neuron-specific enolase (NSE) and S-100B after cardiac arrest. Thirty patients resuscitated from out-of-hospital arrest and treated with induced mild hypothermia for 24 h were included. Original EEG signal was recorded, and burst suppression ratio (BSR), RE, SE, and wavelet subband entropy (WSE) were calculated. Neurological outcome during the six-month period after arrest was assessed with the Glasgow-Pittsburgh Cerebral Performance Categories (CPC). Twenty patients had a CPC of 1-2, one patient had a CPC of 3, and nine patients died (CPC 5). BSR, RE, and SE differed between good (CPC 1-2) and poor (CPC 3-5) outcome groups (p=0.011, p=0.011, p=0.008, respectively) during the first 24 h after arrest. WSE was borderline higher in the good outcome group between 24 and 48 h after arrest (p=0.050). All patients with status epilepticus died, and their WSE values were lower (p=0.022). S-100B was lower in the good outcome group upon arrival at the intensive care unit (p=0.010). After hypothermia treatment, NSE and S-100B values were lower (p=0.002 for both) in the good outcome group. The pulsatile index was also lower in the good outcome group (p=0.004). In conclusion, the incidence of awareness in outpatient anesthesia did not differ from that in inpatient anesthesia. Outpatients are not at increased risk for intraoperative awareness relative to inpatients undergoing general anesthesia. SE, RE, and BIS showed non-zero values that normally indicate cortical neuronal function, but were in these subjects mostly due to artifacts after clinical brain death diagnosis. Entropy was more resistant to artifacts than BIS. During general anesthesia and surgery, SSI values were lower in patients with interscalene brachial plexus block covering the sites of nociceptive stimuli. In detecting nociceptive stimuli, SSI performed better than HR, blood pressure, or RE. BSR, RE, and SE differed between the good and poor neurological outcome groups during the first 24 h after cardiac arrest, and they may be an aid in differentiating patients with good neurological outcomes from those with poor outcomes after out-of-hospital cardiac arrest.
Resumo:
Lasten ylähengitystiekirurgia (kita-nielurisojen poisto ja tärykalvon putkitus) on länsimaissa erittäin yleistä. Leikkausten lukumäärät vaihtelevat niin kansallisesti kuin kansainvälisestikin, mutta selvää syytä näille eroille ei tiedetä. Hoitosuositusten merkitys käytäntöihin on kyseenalaistettu ja voi olla, ettei hoitosuosituksia noudateta. Leikkaukset saattavat aiheuttaa lapsipotilaille psykologisen vamman, ja lisäksi niihin sisältyy komplikaatioiden, jopa kuoleman, vaara. Jotta haittoja voidaan välttää, on tärkeää tunnistaa ne lapset, jotka hyötyvät leikkauksesta. Ongelma on paitsi lääketieteellinen, myös taloudellinen: ylähengitystiekirurgiasta aiheutuu merkittäviä kuluja. Leikkausmäärien arvioiminen on tärkeää, jotta leikkauskäytäntöjä voidaan järkeistää. Tässä väitöskirjatyössä tutkittiin ylähengitystieleikkausten määriä Suomessa ja Norjassa sekä näiden kahden maan välillä. Aiempaa tutkimusta aiheesta ei kummassakaan maassa ole tehty. Kitarisanpoiston, välikorvan putkituksen, tärykalvopiston, nielurisanpoiston ja kita- ja nielurisanpoiston leikkausmäärät saatiin kansallisista tietokannoista. Lukuja verrattiin ko. maan lasten lukumäärään, maantieteelliseen sijoittumiseen sekä lasten ikään ja sukupuoleen. Lisäksi leikkausmääriä arvioitiin suhteessa korva-, nenä- ja kurkkulääkäreiden sekä yleislääkäreiden määrään, maantieteelliseen sijoittumiseen ja lääkäreiden ikään ja sukupuoleen. Leikkausten määrissä havaittiin suurta vaihtelua niin Suomessa kuin Norjassa. Suomessa suurimmat erot leikkausmäärissä löydettiin läntisen ja itäisen miljoonapiirin välillä. Läntisessä piirissä tehtiin lähes kaksin kertaa enemmän leikkauksia kuin itäisessä piirissä. Norjassa suurimmat erot olivat pohjoisen ja itäisen piirin välillä. Pohjoisessa piirissä tehtiin kaksinkertainen määrä leikkauksia itäiseen piirrin verrattuna. Suomessa tehtiin tutkimuksen koko aikavälillä enemmän kitarisanpoistoja kuin Norjassa, mutta ko. leikkausten määrä oli maassamme selvästi laskussa. Vuonna 2002 Suomessa tehtiin 2,5 kertaa enemmän kitarisanpoistoja kuin Norjassa. (Kita)nielurisanpoistoja tehtiin kuitenkin Suomessa vähemmän kuin Norjassa. Näiden leikkausten määrät pysyivät tutkimuksen aikavälillä Suomessa samalla tasolla, kun Norjassa leikkausmäärät hieman nousivat. Suomalaisia lapsia leikattiin keskimäärin paljon nuorempina kuin norjalaisia lapsia. Tutkimuksessa ei löydetty selitystä ylähengitystieleikkausten määrän suurelle vaihtelulle Suomessa ja Norjassa tai maiden välillä. Kuitenkin Suomessa tehtyjen kitarisanpoistojen huomattavan vähenemisen myötä maiden ylähengitystieleikkausten määrät lähenivät toisiaan.
Resumo:
Cardiac surgery involving cardiopulmonary bypass (CPB) induces activation of inflammation and coagulation systems and is associated with ischemia-reperfusion injury (I/R injury)in various organs including the myocardium, lungs, and intestine. I/R injury is manifested as organ dysfunction. Thrombin, the key enzyme of coagulation , plays a cenral role also in inflammation and contributes to regulation of apoptosis as well. The general aim of this thesis was to evaluate the potential of thrombin inhibition in reducing the adverse effects of I/R injury in myocardium, lungs, and intestine associated with the use of CPB and cardiac surgery. Forty five pigs were used for the studies. Two randomized blinded studies were performed. Animals underwent 75 min of normothermic CPB, 60 min of aortic clamping, and 120 min of reperfusion period. Twenty animals received iv. recombinant hirudin, a selective and effective inbitor of thrombin, or placebo. In a similar setting, twenty animals received an iv-bolus (250 IU/kg) of antithrombin (AT) or placebo. An additional group of 5 animals received 500 IU/kg in an open label setting to test dose response. Generation of thrombin (TAT), coagulation status (ACT), and hemodynamics were measured. Intramucosal pH and pCO2 were measured from the luminal surface of ileum using tonometry simultaneusly with arterial gas analysis. In addition, myocardial, lung, and intestinal biopsies were taken to quantitate leukocyte infiltration (MPO), for histological evaluation, and detection of apoptosis (TUNEL, caspase 3). In conclusion, our data suggest that r-hirudin may be an effective inhibitor of reperfusion induced thrombin generation in addition to being a direct inhibitor of preformed thrombin. Overall, the results suggest that inhibition of thrombin, beyond what is needed for efficient anticoagulation by heparin, has beneficial effects on myocardial I/R injury and hemodynamics during cardiac surgery and CPB. We showed that infusion of the thrombin inhibitor r-hirudin during reperfusion was associated with attenuated post ischemia left ventricular dysfunction and decreased systemic vascular resistance. Consequently microvascular flow was improved during ischemia-reperfusion injury. Improved recovery of myocardium during the post-ischemic reperfusion period was associated with significantly less cardiomyocyte apoptosis and with a trend in anti-inflammatory effects. Thus, inhibition of reperfusion induced thrombin may offer beneficial effects by mechanisms other than direct anticoagulant effects. AT, in doses with a significant anticoagulant effect, did not alleviate myocardial I/R injury in terms of myocardial recovery, histological inflammatory changes or post-ischemic troponin T release. Instead, AT attenuated reperfusion induced increase in pulmonary pressure after CPB. Taken the clinical significance of postoperative pulmonary hemodynamics in patients undergoing cardiopulmonary bypass, the potential positive regulatory role of AT and clinical implications needs to be studied further. Inflammatory response in the gut wall proved to be poorly associated with perturbed mucosal perfusion and the animals with the least neutrophil tissue sequestration and I/R related histological alterations tended to have the most progressive mucosal hypoperfusion. Thus, mechanisms of low-flow reperfusion injury during CPB can differ from the mechanisms seen in total ischemia reperfusion injury.
Resumo:
Background: Congenital heart defects include a wide range of inborn malformations. Depending on the defect, the life expectancy of a newborn with cardiac anomaly varies from a few days to a normal life span. In most instances surgery, is the only treatment available. The late results of surgery have not been comprehensively investigated. Aims: Mortality, morbidity and the life situation of all Finnish patients who had been operated on for congenital heart defect during childhood were investigated. Methods: Patient and surgical data were gathered from all hospitals that had performed heart surgeries on children. Late mortality and survival data were obtained from the population registry, and the causes of deaths from Statistics Finland. Morbidity of patients operated on during 1953-1989 was assessed by the usage of medicines. The pharmacotherapy data of patients and controls were obtained from the Social Insurance Institute. The life situation of patients was surveyed by mailed questionnaire. Survival, causes of deaths and life situation of patients were compared with those of the general population. Results: A total of 7240 cardiac operations were performed on 6461 children during the first 37 years of cardiac surgery (1953-1989). The number of procedures constantly rose during this period, and the increase continued in later years. The patient material varied over time, as more defects became surgically treatable. During 1953-1989 the operative mortality (death within 30 days of surgery) was 6.9%. In the 1990s a slight rise occurred in early mortality, as increasingly complicated patients were surgically treated. During 2000-2003 practically no defects were beyond the operative range. Thus, the operative mortality of 4.4% was excellent, decreasing even further to 2.0% in 2004-2007. The overall 45-year survival of patients operated on in 1953-1989 was 78%, and the corresponding figure for the general population was 93%. Survival depended on the defect, being worst among patients with univentricular heart. Late survival was also better during the 1990s and at the beginning of the 21st century. Of the 6028 early survivors, 592 died late (>30 days) after surgery. A total of 397 deaths (67%) were related and 185 (31%) unrelated to congenital heart defect. The cause of death was unknown in 10 cases. Of those 5774 patients who survived their first operation and had complete follow-up, 16% were operated on several times. Seventeen percent of patients used medicines for cardiac symptoms (heart failure, arrhythmia, hypertension and coronary disease). Patients risk of using cardiac medicines was 2.16 (Cl 1.97-2.37) times higher than that of controls. Patients also had more genetic syndromes and mental retardation and more often used medicines for asthma and epilepsy. Adult patients who had been operated on as children had coped surprisingly well with their defects. Their level of education was similar and their employment level even higher than expected, and they were living in a steady relationship as often as the general population. Conclusions: Cardiac surgery developed rapidly, and nowadays practically all defects can be treated. The overall survival of all operated patients was 78%, 16% less than that of the general population. However, it was significantly better than the anticipated natural survival. However, many patients had health problems; 16% needed reoperations and 17% cardiac medicines to maintain their condition. Most of the patients assessed their general health as good and lived a normal life.
Resumo:
The present study addressed the epistemology of teachers’ practical knowledge. Drawing from the literature, teachers’ practical knowledge is defined as all teachers’ cognitions (e.g., beliefs, values, motives, procedural knowing, and declarative knowledge) that guide their practice of teaching. The teachers’ reasoning that lies behind their practical knowledge is addressed to gain insight into its epistemic nature. I studied six class teachers’ practical knowledge; they teach in the metropolitan region of Helsinki. Relying on the assumptions of the phenomenographic inquiry, I collected and analyzed the data. I analyzed the data in two stages where the first stage involved an abductive procedure, and the second stage an inductive procedure for interpretation, and thus developed the system of categories. In the end, a quantitative analysis nested into the qualitative findings to study the patterns of the teachers’’ reasoning. The results indicated that teachers justified their practical knowledge based on morality and efficiency of action; efficiency of action was found to be presented in two different ways: authentic efficiency and naïve efficiency. The epistemic weight of morality was embedded in what I call “moral care”. The core intention of teachers in the moral care was the commitment that they felt about the “whole character” of students. From this perspective the “dignity” and the moral character of the students should not replaced for any other “instrumental price”. “Caring pedagogy” was the epistemic value of teachers’ reasoning in the authentic efficiency. The central idea in the caring pedagogy was teachers’ intentions to improve the “intellectual properties” of “all or most” of the students using “flexible” and “diverse” pedagogies. However, “regulating pedagogy” was the epistemic condition of practice in the cases corresponding to naïve efficiency. Teachers argued that an effective practical knowledge should regulate and manage the classroom activities, but the targets of the practical knowledge were mainly other “issues “or a certain percentage of the students. In these cases, the teachers’ arguments were mainly based on the notion of “what worked” regardless of reflecting on “what did not work”. Drawing from the theoretical background and the data, teachers’ practical knowledge calls for “praxial knowledge” when they used the epistemic conditions of “caring pedagogy” and “moral care”. It however calls for “practicable” epistemic status when teachers use the epistemic condition of regulating pedagogy. As such, praxial knowledge with the dimensions of caring pedagogy and moral care represents the “normative” perspective on teachers’ practical knowledge, and thus reflects a higher epistemic status in comparison to “practicable” knowledge, which represents a “descriptive” perception toward teachers’ practical knowledge and teaching.
Resumo:
Although the principle of equal access to medically justified treatment has been promoted by official health policies in many Western health care systems, practices do not completely meet policy targets. Waiting times for elective surgery vary between patient groups and regions, and growing problems in the availability of services threaten equal access to treatment. Waiting times have come to the attention of decision-makers, and several policy initiatives have been introduced to ensure the availability of care within a reasonable time. In Finland, for example, the treatment guarantee came into force in 2005. However, no consensus exists on optimal waiting time for different patient groups. The purpose of this multi-centre randomized controlled trial was to analyse health-related quality of life, pain and physical function in total hip or knee replacement patients during the waiting time and to evaluate whether the waiting time is associated with patients health outcomes at admission. This study also assessed whether the length of waiting time is associated with social and health services utilization in patients awaiting total hip or knee replacement. In addition, patients health-related quality of life was compared with that of the general population. Consecutive patients with a need for a primary total hip or knee replacement due to osteoarthritis were placed on the waiting list between August 2002 and November 2003. Patients were randomly assigned to a short waiting time (maximum 3 months) or a non-fixed waiting time (waiting time not fixed in advance, instead the patient followed the hospitals routine practice). Patients health-related quality of life was measured upon being placed on the waiting list and again at hospital admission using the generic 15D instrument. Pain and physical function were evaluated using the self-report Harris Hip Score for hip patients and a scale modified from the Knee Society Clinical Rating System for knee patients. Utilization measures were the use of home health care, rehabilitation and social services, physician visits and inpatient care. Health and social services use was low in both waiting time groups. The most common services used while waiting were rehabilitation services and informal care, including unpaid care provided by relatives, neighbours and volunteers. Although patients suffered from clear restrictions in usual activities and physical functioning, they seemed primarily to lean on informal care and personal networks instead of professional care. While longer waiting time did not result in poorer health-related quality of life at admission and use of services during the waiting time was similar to that at the time of placement on the list, there is likely to be higher costs of waiting by people who wait longer simply because they are using services for a longer period. In economic terms, this would represent a negative impact of waiting. Only a few reports have been published of the health-related quality of life of patients awaiting total hip or knee replacement. These findings demonstrate that, in addition to physical dimensions of health, patients suffered from restrictions in psychological well-being such as depression, distress and reduced vitality. This raises the question of how to support patients who suffer from psychological distress during the waiting time and how to develop strategies to improve patients initiatives to reduce symptoms and the burden of waiting. Key words: waiting time, total hip replacement, total knee replacement, health-related quality of life, randomized controlled trial, outcome assessment, social service, utilization of health services
Resumo:
Many of the genes predisposing to highly penetrant colorectal cancer (CRC) syndromes, including hereditary non-polyposis colorectal cancer (MLH1, MSH2, MSH6, PMS2), familial adenomatous polyposis (APC), Peutz-Jeghers syndrome (LKB1), juvenile polyposis (SMAD4, BMPR1A), MYH-associated polyposis (MYH), and Cowden syndrome (PTEN) have already been discovered. Identification of these genes has allowed a more precise classification of the hereditary CRC syndromes and provided a means for predictive genetic testing and surveillance. Some of the genes are also involved in sporadic cancer forms, and therefore the investigation of the rare CRC syndromes has been a breakthrough for general cancer research. Despite the accumulating knowledge on hereditary cancer syndromes, a significant number of familial CRCs remain molecularly unexplained after genetic testing, reflecting the possibility of other predisposing genes or existence of novel syndromes. Moreover, genetic variants conferring low-penetrance risk are still largely unknown. In this study, we examined the role of some new high- and low-penetrance alleles on CRC predisposition. We identified disease causing MYH mutations in a subset (9%) of patients with APC and AXIN2 mutation negative adenomatous polyposis. Due to differences in the pattern of inheritance and clinical manifestation, screening for mutations in MYH is beneficial in view of genetic counselling and surveillance. A novel functionally deficient MYH founder mutation A459D was identified in the Finnish population, and this finding had immediate clinical implications for genetic counselling of at risk families. Many patients with hamartomatous polyposis remain without molecular diagnosis due to atypical phenotypes. We therefore sought to classify 49 patients with unexplained hamartomatous or hyperplastic/mixed polyposis by extensive molecular analyses of PTEN, LKB1, BMPR1A, SMAD4, ENG, BRAF, MYH, and BHD along with revision of polyp histology. Mutations were identified in 11/49 (22%) of the patients. In 6 cases the molecular diagnosis was re-classified guiding surveillance and decisions for prophylactic surgery. Re-evaluation of polyp histology with subsequent more accurate selection of candidate gene analyses is beneficial and can be recommended for patients with unexplained polyposis. Furthermore, germline mutations in ENG underlying juvenile polyposis were described for the first time, characterizing a possible novel genetically defined form of hereditary CRC. Association analyses on two putative low-penetrance alleles, NOD2 3020insC and MDM2 SNP309 were performed in a population-based series of 1042 Finnish CRC patients and in cancer-free controls. In contrast to previous results, NOD2 3020insC did not associate with CRC or age at disease onset in the Finnish population. These data suggest that NOD2 3020insC alone might not be sufficient for CRC predisposition. MDM2 SNP309 was as common in the CRC cohort as in the healthy controls. Interesting trends, however, were observed, which after correction for multiple testing did not reach statistical significance. SNP309 was more common in female CRC patients and a trend towards an earlier age at disease onset was observed in women with SNP309. Subsequent studies have supported this observation and SNP309 could affect gender- or hormone-related tumorigenesis. Finally, a large-scale unbiased effort was designed to characterize the complete mutatome of CRC with microsatellite instability (MSI). Using an approach combining expression microarray and genome database searches, we were able to identify putative MSI target genes. Further characterization of one of the genes suggested that it might play a role also in microsatellite stable CRC and Peutz-Jeghers syndrome pathogenesis.
Resumo:
Viral infections caused by herpesviruses are common complications after organ transplantation and they are associated with substantial morbidity and even mortality. Herpesviruses remain in a latent state in a host after primary infection and may reactivate later. CMV infection is the most important viral infection after liver transplantation. Less is known about the significance of human herpesvirus-6 (HHV-6). EBV is believed to play a major role in the development of post-transplant lymphoproliferative disorders (PTLD). The aim of this study was to investigate the CMV-, EBV- and HHV-6 DNAemia after liver transplantation by frequent monitoring of adult liver transplant patients. The presence of CMV, EBV and HHV-6 DNA were demonstrated by in situ hybridization assays and by real-time PCR methods from peripheral blood specimens. CMV and HHV-6 antigens were demonstrated by antigenemia assays and compared to the viral DNAemia. The response to antiviral therapy was also investigated. CMV-DNAemia appeared earlier than CMV pp65-antigenemia after liver transplantation. CMV infections were treated with ganciclovir. However, most of the treated patients demonstrated persistence of CMV-DNA for up to several months. Continuous CMV-DNA expression of peripheral blood leukocytes showed that the virus is not eliminated by ganciclovir and recurrences can be expected during several months after liver transplantation. HHV-6 DNAemia / antigenemia was common and occurred usually within the first three months after liver transplantation together with CMV. The HHV-6 DNA expression in peripheral blood mononuclear cells correlated well with HHV-6 antigenemia. Antiviral treatment significantly decreased the number of HHV-6 DNA positive cells, demonstrating the response to ganciclovir treatment. Clinically silent EBV reactivations with low viral loads were relatively common after liver transplantation. These EBV-DNAemias usually appeared within the first three months after liver transplantation together with betaherpesviruses (CMV, HHV-6, HHV-7). One patient developed high EBV viral loads and developed PTLD. These results indicate that frequent monitoring of EBV-DNA levels can be useful to detect liver transplant patients at risk of developing PTLD.
Resumo:
Background: Patients may need massive volume-replacement therapy after cardiac surgery because of large fluid transfer perioperatively, and the use of cardiopulmonary bypass. Hemodynamic stability is better maintained with colloids than crystalloids but colloids have more adverse effects such as coagulation disturbances and impairment of renal function than do crystalloids. The present study examined the effects of modern hydroxyethyl starch (HES) and gelatin solutions on blood coagulation and hemodynamics. The mechanism by which colloids disturb blood coagulation was investigated by thromboelastometry (TEM) after cardiac surgery and in vitro by use of experimental hemodilution. Materials and methods: Ninety patients scheduled for elective primary cardiac surgery (Studies I, II, IV, V), and twelve healthy volunteers (Study III) were included in this study. After admission to the cardiac surgical intensive care unit (ICU), patients were randomized to receive different doses of HES 130/0.4, HES 200/0.5, or 4% albumin solutions. Ringer’s acetate or albumin solutions served as controls. Coagulation was assessed by TEM, and hemodynamic measurements were based on thermodilutionally measured cardiac index (CI). Results: HES and gelatin solutions impaired whole blood coagulation similarly as measured by TEM even at a small dose of 7 mL/kg. These solutions reduced clot strength and prolonged clot formation time. These effects were more pronounced with increasing doses of colloids. Neither albumin nor Ringer’s acetate solution disturbed blood coagulation significantly. Coagulation disturbances after infusion of HES or gelatin solutions were clinically slight, and postoperative blood loss was comparable with that of Ringer’s acetate or albumin solutions. Both single and multiple doses of all the colloids increased CI postoperatively, and this effect was dose-dependent. Ringer’s acetate had no effect on CI. At a small dose (7 mL/kg), the effect of gelatin on CI was comparable with that of Ringer’s acetate and significantly less than that of HES 130/0.4 (Study V). However, when the dose was increased to 14 and 21 mL/kg, the hemodynamic effect of gelatin rose and became comparable with that of HES 130/0.4. Conclusions: After cardiac surgery, HES and gelatin solutions impaired clot strength in a dose-dependent manner. The potential mechanisms were interaction with fibrinogen and fibrin formation, resulting in decreased clot strength, and hemodilution. Although the use of HES and gelatin inhibited coagulation, postoperative bleeding on the first postoperative morning in all the study groups was similar. A single dose of HES solutions improved CI postoperatively more than did gelatin, albumin, or Ringer’s acetate. However, when administered in a repeated fashion, (cumulative dose of 14 mL/kg or more), no differences were evident between HES 130/0.4 and gelatin.
Resumo:
The risk is obvious for soft tissue complications after operative treatment of the Achilles tendon, calcaneal bone or after ankle arthroplasty. Such complications after malleolar fractures are, however, seldom seen. The reason behind these complications is that the soft tissue in this region is tight and does not allow much tension to the wound area after surgery. Furthermore the area of operation may be damaged by swelling after the injury, or can be affected by peripheral vascular disease. While complications in this area are unavoidable, they can be diminished. This study attempts to highlight the possible predisposing factors leading to complications in these operations and on the other hand, to determine the solutions to solve soft tissue problems in this region. The study consists of five papers. The first article is a reprint on the soft tissue reconstruction of 25 patients after their complicated Achilles tendon surgeries were analysed. The second study reviews a series of 126 patients after having undergone an operative treatment of calcaneal bone fractures and analyses the complications and possible reasons behind them. The third part analyses a series of corrections of 35 soft tissue complications after calcaneal fracture operations. The fourth part reviews a series of 7 patients who had undergone complicated ankle arthroplasties. The last article presents a series of post operative lateral defects of the ankle treated with a less frequently used distally based peroneus brevis muscle flap and analyses the results. What can be conducted from these studies is that in general, the results after the correction of even severe soft tissue complications in the ankle region are good. For the small defects around the Achilles tendon, the local flaps are useful, but the larger defects are best treated with a free flap. We found that a long delay from trauma to surgery and a long operating time were predisposing factors that lead to soft tissue complications after operatively treated calcaneal bone fractures. The more severe the injury, the greater the risk for wound complication. Surprisingly, the long-term results after infected calcaneal osteosyntheses were acceptable and the calcaneal bone seems to tolerate chronic infections very well if the soft tissue is reconstructed successfully. Behind the complicated ankle arthroplasties, unexpectedly high number of cases experiencing arteriosclerosis of the lower extremity was found. These complications lead to ankle fusion but can be solved with a free flap if the vascularity is intact or can be reconstructed. For this reason a vascular examination of the lower extremity arteries of the patients going to ankle arthroplasty is strongly recommended. Moreover postoperative lateral malleolar wound infections which typically create lateral ankle defects can successfully be treated with a peroneus brevis muscle flap covered with a free skin graft.
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With transplant rejection rendered a minor concern and survival rates after liver transplantation (LT) steadily improving, long-term complications are attracting more attention. Current immunosuppressive therapies, together with other factors, are accompanied by considerable long-term toxicity, which clinically manifests as renal dysfunction, high risk for cardiovascular disease, and cancer. This thesis investigates the incidence, causes, and risk factors for such renal dysfunction, cardiovascular risk, and cancer after LT. Long-term effects of LT are further addressed by surveying the quality of life and employment status of LT recipients. The consecutive patients included had undergone LT at Helsinki University Hospital from 1982 onwards. Data regarding renal function – creatinine and estimated glomerular filtration rate (GFR) – were recorded before and repeatedly after LT in 396 patients. The presence of hypertension, dyslipidemia, diabetes, impaired fasting glucose, and overweight/obesity before and 5 years after LT was determined among 77 patients transplanted for acute liver failure. The entire cohort of LT patients (540 patients), including both children and adults, was linked with the Finnish Cancer Registry, and numbers of cancers observed were compared to site-specific expected numbers based on national cancer incidence rates stratified by age, gender, and calendar time. Health-related quality of life (HRQoL), measured by the 15D instrument, and employment status were surveyed among all adult patients alive in 2007 (401 patients). The response rate was 89%. Posttransplant cardiovascular risk factor prevalence and HRQoL were compared with that in the age- and gender-matched Finnish general population. The cumulative risk for chronic kidney disease increased from 10% at 5 years to 16% at 10 years following LT. GFR up to 10 years after LT could be predicted by the GFR at 1 year. In patients transplanted for chronic liver disease, a moderate correlation of pretransplant GFR with later GFR was also evident, whereas in acute liver failure patients after LT, even severe pretransplant renal dysfunction often recovered. By 5 years after LT, 71% of acute liver failure patients were receiving antihypertensive medications, 61% were exhibiting dyslipidemia, 10% were diabetic, 32% were overweight, and 13% obese. Compared with the general population, only hypertension displayed a significantly elevated prevalence among patients – 2.7-fold – whereas patients exhibited 30% less dyslipidemia and 71% less impaired fasting glucose. The cumulative incidence of cancer was 5% at 5 years and 13% at 10. Compared with the general population, patients were subject to a 2.6-fold cancer risk, with non-melanoma skin cancer (standardized incidence ratio, SIR, 38.5) and non-Hodgkin lymphoma (SIR 13.9) being the predominant malignancies. Non-Hodgkin lymphoma was associated with male gender, young age, and the immediate posttransplant period, whereas old age and antibody induction therapy raised skin-cancer risk. HRQoL deviated clinically unimportantly from the values in the general population, but significant deficits among patients were evident in some physical domains. HRQoL did not seem to decrease with longer follow-up. Although 87% of patients reported improved working capacity, data on return to working life showed marked age-dependency: Among patients aged less than 40 at LT, 70 to 80% returned to work, among those aged 40 to 50, 55%, and among those above 50, 15% to 28%. The most common cause for unemployment was early retirement before LT. Those patients employed exhibited better HRQoL than those unemployed. In conclusion, although renal impairment, hypertension, and cancer are evidently common after LT and increase with time, patients’ quality of life remains comparable with that of the general population.
Resumo:
Mediastinitis as a complication after cardiac surgery is rare but disastrous increasing the hospital stay, hospital costs, morbidity and mortality. It occurs in 1-3 % of patients after median sternotomy. The purpose of this study was to find out the risk factors and also to investigate new ways to prevent mediastinitis. First, we assessed operating room air contamination monitoring by comparing the bacteriological technique with continuous particle counting in low level contamination achieved by ultra clean garment options in 66 coronary artery bypass grafting operations. Second, we examined surgical glove perforations and the changes in bacterial flora of surgeons' fingertips in 116 open-heart operations. Third, the effect of gentamicin-collagen sponge on preventing surgical site infections (SSI) was studied in randomized controlled study with 557 participants. Finally, incidence, outcome, and risk factors of mediastinitis were studied in over 10,000 patients. With the alternative garment and textile system (cotton group and clean air suit group), the air counts fell from 25 to 7 colony-forming units/m3 (P<0.01). The contamination of the sternal wound was reduced by 46% and that of the leg wound by >90%. In only 17% operations both gloves were found unpunctured. Frequency of glove perforations and bacteria counts of hands were found to increase with operation time. With local gentamicin prophylaxis slightly less SSIs (4.0 vs. 5.9%) and mediastinitis (1.1 vs. 1.9%) occurred. We identified 120/10713 cases of postoperative mediastinitis (1.1%). During the study period, the patient population grew significantly older, the proportion of women and patients with ASA score >3 increased significantly. In multivariate logistic regression analysis, the only significant predictor for mediastinitis was obesity. Continuous particle monitoring is a good intraoperative method to control the air contamination related to the theatre staff behavior during individual operation. When a glove puncture is detected, both gloves are to be changed. Before donning a new pair of gloves, the renewed disinfection of hands will help to keep their bacterial counts lower even towards the end of long operation. Gentamicin-collagen sponge may have beneficial effects on the prevention of SSI, but further research is needed. Mediastinitis is not diminishing. Larger populations at risk, for example proportions of overweight patients, reinforce the importance of surveillance and pose a challenge in focusing preventive measures.
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In anisometropia, the two eyes have unequal refractive power. Anisometropia is a risk factor for amblyopia. The visual deficiencies are thought to be irreversible after the first decade of life. There is, however, accumulating evidence that neural plasticity exists also in adult brains. The aim of this study was to investigate functional outcome of excimer laser refractive surgery in adult anisometropic and visually impaired patients. Additional goal was to examine changes in the primary visual cortex (V1) using multifocal functional magnetic resonance imaging (mffMRI) after laser refractive surgery. Study I comprised of 57 anisometropic patients (anisometropia of ≥3.25 diopters) and 174 isometropic myopic subjects formed the control group. A significant improvement in best-spectacle-corrected visual acuity (BSCVA) among myopic control subjects was evident 3 months postoperatively. The improvement in BSCVA was significantly slower for anisometropic patients and the improvement appeared to persist to the end of the follow-up (24 months). In study II we found that refractive surgery may be also successfully used for iathrogenic anisometropia. In Study III we evaluated mildly visually impaired adult patients after refractive surgery. There was a statistically significant improvement in BSCVA among visually impaired patients and the difference in the mean BSCVA between visually impaired patients and isometropic myopic control subjects diminished during follow-up. Study IV was a prospective follow-up trial examining the changes in the primary visual cortex after refractive surgery. Two anisometropic patients and two isometropic myopic patients were examined with a 61-region mffMRI before refractive surgery and at three, six, nine and twelve months postoperatively. In this study, a dramatic decrease in the number of active voxels in the fovea was found among anisometropic patients. The results presented in this thesis revealed that refractive surgery may be successfully used for the treatment of anisometropic adults with both congenital and iatrogenic anisometropia and for mildly visually impaired adults. The findings in conclusion strengthen our hypothesis of plastic changes in the visual cortex of adult anisometropic and mildly visually impaired patients after refractive surgery.