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Informācijas meklēšanas pamati elektroniskajos resursos

(Rīgas Stradiņa universitāte, 2025) Znotiņa, Inga; Vītola, Beāte; Rīgas Stradiņa universitāte

Grāmata sniedz ieskatu pamatlietās, kas jāņem vērā, meklējot informāciju elektroniskajos resursos. Galvenie apskatītie jautājumi – informācijas veidi, navigācija informācijas plūsmā, informācijas meklēšanas process – atslēgvārdu noteikšana un vajadzīgās informācijas izgūšana, MeSH meklēšana, informācijas ētiska izmantošana. Grāmata ir paredzēta studentiem un pētniekiem, kuri uzsāk studiju vai pētniecības procesu un kuriem nav pietiekamu zināšanu, kā efektīvāk meklēt informāciju elektroniskajos resursos.

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Endovascular Transvenous Femoropopliteal Bypass and its Effectiveness Compared to Open Bypass in the Treatment of Long Segment Superficial Femoral Artery Occlusion. Summary of the Doctoral Thesis

(Rīga Stradiņš University, 2025) Rumba, Roberts; Krieviņš, Dainis; Gardovskis, Jānis

Lower extremity peripheral artery disease (PAD) is among the most common manifestations of atherosclerosis. Due to aging of population, this pathology is only expected to rise in prevalence. It causes significant reduction of quality of life and, in case of critical limb ischemia, poses serious threat to limb and patient’s life. Superficial femoral artery (SFA) is often severely affected by atherosclerosis, making it the focus of extensive research and innovation in vascular technology. Short and simple lesions can be managed effectively by standard endovascular modalities, whereas long and complex SFA pathologies historically were treated by open femoropopliteal bypass. However, patients with severe SFA disease are usually in advanced age, often frail, highly comorbid and thus have increased risk for open surgery. For the past two decades, vascular surgeons and invasive radiologists have debated and studied the question of which revascularisation method is superior in case of long and complex SFA lesions. Advocates of endovascular technique state lower periprocedural morbidity and mortality, shorter length of hospital stay and less wound complications. Proponents of open surgery claim higher long-term patency, less secondary interventions and lower rates of amputation. In an effort to combine the benefits of both approaches, endovascular transvenous femoropopliteal (ETFP) bypass was introduced. In this endovascular procedure, bypass from proximal SFA to above-the-knee popliteal artery is created through the deep venous system. This novel technique was investigated thoroughly in different aspects. The study was conducted in Pauls Stradiņš Clinical University Hospital between 2015 and 2020. It comprised of 52 patients (54 procedures) in study group and two control groups – 83 patients in prosthetic and 48 patients in venous bypass group. Patients with Rutherford 3–5, ankle-brachial-index (ABI) < 0.7, long (> 10 cm) TASC C and D lesions and at least one patent crural vessel were included in study group. Only patients for whom both open and endovascular treatment was feasible were included in this study. All procedures were performed by a designated team of vascular surgeons and interventional radiologists. Control groups were formed of patients with long SFA lesions who were not eligible for ETFP bypass procedure and who agreed to take part in this follow-up patency study. Following all procedures and open surgeries, control visits were performed with 6-month intervals for a total duration of 3 years. During visits, clinical assessment, plethysmography (study group) and Duplex ultrasound (DUS) was performed to assess graft patency, inflow and outflow vessels, and venous system in patients with transvenous grafts. Transvenous bypass group received dual antiplatelet treatment throughout the 3-year follow-up. Patients in control groups received either standard aspirin monotherapy, dual antiplatelet therapy, or anticoagulants if indicated by coronary artery disease or arrhythmia, respectively. The dissertation is organised as a collection of four peer-reviewed publications. First of all, we analysed and published long term venous results, which consisted of clinical and physiology assessment. Secondly, we published data regarding ETFP bypass patency. This allows us to compare it to other endovascular treatment methods. Following that, we compared the results of ETFP bypass to open surgery, both with saphenous vein and prosthetic bypass. In parallel, we conducted a study analysing DUS and ABI in the follow-up surveillance of patients after ETFP bypass. To the best of my knowledge, there are no publications reporting venous system physiology data in the context of ETFP bypass. Our results indicate that ETFP bypass does not significantly alter venous clinical symptoms and function within 3-year follow-up period. Venous system is capable of adaptation to a large stent-graft without reducing functional performance. Although we noted and early increase in venous symptoms, these changes were transient and returned to baseline by 6-months. Risk of symptomatic deep vein thrombosis following ETFP bypass is low. However, significant number of patients developed asymptomatic non-occlusive thrombi on stent-graft. Therefore, we recommend adding a low-dose anticoagulant to postprocedural medical regimen for one year. We were among the few centres in the world to publish patency data of this innovative technique. In our centre, primary patency was acceptable at 12-months (72.2 %) but reduced to 43.8 % at 3 years. Secondary patency was 92.6 % at 12 months and remained high during the study period (73.9 % at 3 years). This indicates the need for stringent surveillance and secondary interventions to maintain optimal patency of this novel device. Comparison with open femoropopliteal bypass gave us valuable practical insight. Our results demonstrate superiority of venous bypass over ETFP and prosthetic open bypass. ETFP bypass is an option with comparable primary-assisted and secondary patency to venous bypass, but will require reinterventions to provide favourable results. Whenever adequate saphenous vein is available and surgery can be tolerated, it should be the first-line option for above-the-knee open revascularisation. Prosthetic bypass should only be used if no other options are available. Diagnostic modalities used for follow-up were DUS and ABI measurements. Our study results indicate that both of these tools in combination provide the best opportunity to diagnose device-related and vascular problems. Timely diagnosis and intervention are necessary to improve our results. In summary, ETFP bypass is the method of choice for patients with infection and inadequate vein for bypass, as well as for severely adipose patients. In addition, dense scar tissue are present following previous irradiation and open surgery, thus ETFP bypass should be considered in these situations as well.

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Endovascular Transvenous Femoropopliteal Bypass and its Effectiveness Compared to Open Bypass in the Treatment of Long Segment Superficial Femoral Artery Occlusion. Doctoral Thesis

(Rīga Stradiņš University, 2025) Rumba, Roberts; Krieviņš, Dainis; Gardovskis, Jānis

Lower extremity peripheral artery disease (PAD) is among the most common manifestations of atherosclerosis. Due to aging of population, this pathology is only expected to rise in prevalence. It causes significant reduction of quality of life and, in case of critical limb ischemia, poses serious threat to limb and patient’s life. Superficial femoral artery (SFA) is often severely affected by atherosclerosis, making it the focus of extensive research and innovation in vascular technology. Short and simple lesions can be managed effectively by standard endovascular modalities, whereas long and complex SFA pathologies historically were treated by open femoropopliteal bypass. However, patients with severe SFA disease are usually in advanced age, often frail, highly comorbid and thus have increased risk for open surgery. For the past two decades, vascular surgeons and invasive radiologists have debated and studied the question of which revascularisation method is superior in case of long and complex SFA lesions. Advocates of endovascular technique state lower periprocedural morbidity and mortality, shorter length of hospital stay and less wound complications. Proponents of open surgery claim higher long-term patency, less secondary interventions and lower rates of amputation. In an effort to combine the benefits of both approaches, endovascular transvenous femoropopliteal (ETFP) bypass was introduced. In this endovascular procedure, bypass from proximal SFA to above-the-knee popliteal artery is created through the deep venous system. This novel technique was investigated thoroughly in different aspects. The study was conducted in Pauls Stradiņš Clinical University Hospital between 2015 and 2020. It comprised of 52 patients (54 procedures) in study group and two control groups – 83 patients in prosthetic and 48 patients in venous bypass group. Patients with Rutherford 3–5, ankle-brachial-index (ABI) < 0.7, long (> 10 cm) TASC C and D lesions and at least one patent crural vessel were included in study group. Only patients for whom both open and endovascular treatment was feasible were included in this study. All procedures were performed by a designated team of vascular surgeons and interventional radiologists. Control groups were formed of patients with long SFA lesions who were not eligible for ETFP bypass procedure and who agreed to take part in this follow-up patency study. Following all procedures and open surgeries, control visits were performed with 6-month intervals for a total duration of 3 years. During visits, clinical assessment, plethysmography (study group) and Duplex ultrasound (DUS) was performed to assess graft patency, inflow and outflow vessels, and venous system in patients with transvenous grafts. Transvenous bypass group received dual antiplatelet treatment throughout the 3-year follow-up. Patients in control groups received either standard aspirin monotherapy, dual antiplatelet therapy, or anticoagulants if indicated by coronary artery disease or arrhythmia, respectively. The dissertation is organised as a collection of four peer-reviewed publications. First of all, we analysed and published long term venous results, which consisted of clinical and physiology assessment. Secondly, we published data regarding ETFP bypass patency. This allows us to compare it to other endovascular treatment methods. Following that, we compared the results of ETFP bypass to open surgery, both with saphenous vein and prosthetic bypass. In parallel, we conducted a study analysing DUS and ABI in the follow-up surveillance of patients after ETFP bypass. To the best of my knowledge, there are no publications reporting venous system physiology data in the context of ETFP bypass. Our results indicate that ETFP bypass does not significantly alter venous clinical symptoms and function within 3-year follow-up period. Venous system is capable of adaptation to a large stent-graft without reducing functional performance. Although we noted and early increase in venous symptoms, these changes were transient and returned to baseline by 6-months. Risk of symptomatic deep vein thrombosis following ETFP bypass is low. However, significant number of patients developed asymptomatic non-occlusive thrombi on stent-graft. Therefore, we recommend adding a low-dose anticoagulant to postprocedural medical regimen for one year. We were among the few centres in the world to publish patency data of this innovative technique. In our centre, primary patency was acceptable at 12-months (72.2 %) but reduced to 43.8 % at 3 years. Secondary patency was 92.6 % at 12 months and remained high during the study period (73.9 % at 3 years). This indicates the need for stringent surveillance and secondary interventions to maintain optimal patency of this novel device. Comparison with open femoropopliteal bypass gave us valuable practical insight. Our results demonstrate superiority of venous bypass over ETFP and prosthetic open bypass. ETFP bypass is an option with comparable primary-assisted and secondary patency to venous bypass, but will require reinterventions to provide favourable results. Whenever adequate saphenous vein is available and surgery can be tolerated, it should be the first-line option for above-the-knee open revascularisation. Prosthetic bypass should only be used if no other options are available. Diagnostic modalities used for follow-up were DUS and ABI measurements. Our study results indicate that both of these tools in combination provide the best opportunity to diagnose device-related and vascular problems. Timely diagnosis and intervention are necessary to improve our results. In summary, ETFP bypass is the method of choice for patients with infection and inadequate vein for bypass, as well as for severely adipose patients. In addition, dense scar tissue are present following previous irradiation and open surgery, thus ETFP bypass should be considered in these situations as well.

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Endovaskulāra transvenoza femoropopliteāla šuntēšana un tās efektivitāte salīdzinājumā ar vaļēju šuntēšanu gara segmenta virspusējās ciskas artērijas oklūzijas ārstēšanā. Promocijas darba kopsavilkums

(Rīgas Stradiņa universitāte, 2025) Rumba, Roberts; Krieviņš, Dainis; Gardovskis, Jānis

Perifēro artēriju slimība (PAS) ir viena no biežākajām aterosklerozes izpausmēm. Sabiedrībai novecojot, ir sagaidāms PAS gadījumu skaita pieaugums gan Latvijā, gan visā pasaulē. PAS rada izteiktu dzīves kvalitātes pasliktināšanos, turklāt var novest pie kritiskas kāju išēmijas, kura apdraud gan ekstremitātes dzīvotspēju, gan pacienta dzīvību. Virspusējā ciskas artērija (VCA) ir asinsvads, kurš visbiežāk tiek skarts kāju artēriju slimības gadījumā. Līdz ar to liela daļa asinsvadu ķirurģijas pētījumu un inovāciju tiek veltītas tam, kā efektīvāk, drošāk un mazinvazīvāk revaskularizēt VCA. Īsas un salīdzinoši vienkāršas stenozes vai oklūzijas jau ilgstoši var efektīvi risināt ar standarta endovaskulārās ārstēšanas iespējām. Savukārt garas un komplicētas hroniskas VCA oklūzijas lielākoties tiek ārstētas ar vaļēju femoropopliteālu šuntēšanu. Tomēr arvien biežāk pacienti ar šādiem VCA slēgumiem ir gados vecāki, ar sliktu vispārējo veselības stāvokli un multiplām blakusslimībām. Šādās situācijās pacientam ir paaugstināts komplikāciju un nevēlamu notikumu risks, veicot vaļēju šuntēšanas operāciju. Pēdējās divās desmitgadēs asinsvadu ķirurgi un invazīvie radiologi intensīvi diskutējuši un pētījuši to, kura revaskularizācijas metode un kuros gadījumos ir pārāka, ārstējot garus un sarežģītus VCA slēgumus. Endovaskulārās ārstēšanas piekritēji norāda uz zemāku komplikāciju, īpaši brūču komplikāciju, risku, kā arī zemāku mirstību perioperatīvajā periodā, kā arī īsāku hospitalizācijas laiku. Savukārt vaļējas šuntēšanas atbalstītāji vērš uzmanību uz ķirurģijas pārākumu ilgtermiņa šunta caurlaidības ziņā, kā arī mazāku nepieciešamību pēc sekundārām intervencēm un zemāku amputāciju risku. Mēģinot apvienot abu minēto metožu priekšrocības, tika radīta endovaskulāra transvenoza femoropopliteāla (ETFP) šuntēšana. Šīs procedūras laikā tiek izveidots šunts no VCA proksimālās daļas līdz caurlaidīgai paceles artērijai virs ceļa locītavas, šuntu implantējot caur dziļo vēnu sistēmu. Paula Stradiņa klīniskās universitātes slimnīcas Asinsvadu ķirurģijas centrs kā viens no pirmajiem pasaulē veica šīs procedūras, un sekojoši tika analizēti dažādi ar procedūru saistītie aspekti. Pētījums tika veikts Paula Stradiņa klīniskajā universitātes slimnīcā laika posmā no 2015. līdz 2020. gadam. Tajā tika iekļauti 52 pacienti (veiktas 54 procedūras) pētāmajā grupā, kā arī tika izveidotas 2 kontroles grupas – 83 pacienti ar sintētiskās protēzes un 48 pacienti ar autovenozu femoropopliteālu šuntu. Pētāmajā grupā tika iekļauti pacienti ar Rutherforda 3.–5. klīnisko klasi, potītes-augšdelma indeksu (PAI) < 0,7, garām (> 10 cm) VCA oklūzijām un vismaz vienu caurlaidīgu apakšstilba artēriju. Tikai pacienti, kuri bija piemēroti gan endovaskulārai, gan vaļējai šuntēšanai, tika iekļauti pētāmajā grupā. Kontroles grupās tika iekļauti pacienti ar garu VCA oklūziju pēc vaļējas šuntēšanas, kuri neatbilda iekļaušanas kritērijiem endovaskulārajā grupā un kuri piekrita dalībai šuntu caurlaidības novērojuma pētījumā. Pēc revaskularizācijas visiem pacientiem tika veiktas kontroles vizītes ar sešu mēnešu intervālu un kopējo novērojuma ilgumu trīs gadi. Kontroles vizītēs tika veikta klīniskā stāvokļa izvērtēšana, pletismogrāfijas mērījumi (pētāmā grupā) un Duplex ultraskaņas (DUS) izmeklējumi, lai izvērtētu šuntu caurlaidību, ieplūdes un noplūdes asinsvadu stāvokli, venozo sistēmu pacientiem ar transvenoziem šuntiem. Pacienti ETFP grupā saņēma duālu antiagregantu terapiju. Pacienti kontroles grupās pamatā saņēma aspirīna monoterapiju, duālu antiagregantu terapiju (koronāro artēriju slimības gadījumā) vai antikoagulantu (sirds ritma traucējumu gadījumā). Šī disertācija ir strukturēta kā četru recenzētu un starptautiski citētu publikāciju kopa. Vispirms mēs analizējām un publicējām mūsu rezultātus par venozās sistēmas parametru ilgtermiņa izvērtējumu. Tas sastāvēja no klīnisko pazīmju un fizioloģisko parametru analīzes. Otrkārt, tika apkopoti un publicēti ETFP šuntu caurlaidības rādītāji. Tas mums dod iespēju salīdzināt šo endovaskulāro metodi ar citām līdz šim lietotām mazinvazīvās ārstēšanas iespējām. Sekojoši mēs veicām salīdzinājumu starp ETFP šuntēšanu un vaļēju ķirurģisku šuntēšanu gan ar autovēnu, gan sintētisko protēzi. Paralēli šim tika apkopoti dati par ETFP šuntu dinamisku novērošanu pēcoperācijas periodā, izmantojot DUS un PAI mērījumus. Šī ir pirmā publikācija pasaulē par venozās sistēmas fizioloģijas izmaiņām pēc ETFP šuntēšanas. Mēs esam līdz šim vienīgie, kuri izmantoja pletismogrāfiju kā izmeklēšanas metodi un kuriem ir šādi dati. Mūsu rezultāti liecina, ka ETFP šuntēšana nerada būtisku negatīvu ietekmi uz venozās sistēmas funkciju un neizraisa vēnu slimībām raksturīgos simptomus un pazīmes trīs gadu laikā pēc procedūras. Venozā sistēma funkcionāli ir spējīga adaptēties liela kalibra stentprotēzes ievietošanai tajā. Mēs novērojām īslaicīgu vēnu slimības simptomu parādīšanos galvenokārt tūskas veidā, tomēr šīs izmaiņas bija pārejošas un lielākoties izzuda 6 mēnešu laikā. Simptomātiskas dziļo vēnu trombozes risks ETFP šuntēšanas pacientiem ir neliels. Tomēr daļai šādi ārstēto pacientu mēs konstatējām neokluzīvu trombotisku materiālu uz stentprotēzes venozās virsmas. Šī iemesla dēļ mēs rekomendējam vienu gadu pēc ETFP šuntēšanas terapijā pievienot antikoagulantus, lai mazinātu trombotisko komplikāciju risku un nodrošinātu šunta caurlaidību ilgtermiņā. Mēs kā viens no pirmajiem centriem pasaulē publicējām šuntu caurlaidības rādītājus ETFP procedūrām. Primārā caurlaidība gada laikā sasniedza 72,2 %, tomēr pēc trim gadiem šis rādītājs bija samazinājies līdz 43,8 %. Sekundārā caurlaidība gada laikā sasniedza 92,6 % un saglabājās relatīvi augsta līdz pat novērošanas perioda beigām (73,9 % pēc 3 gadiem). Šie rezultāti norāda uz pēcoperācijas novērojumu un sekundāru procedūru nepieciešamību, lai nodrošinātu optimālus rezultātus. Salīdzinot šuntu caurlaidības rādītājus starp vaļēju un ETFP šuntēšanu, ir skaidrs, ka labas kvalitātes vēna ir pārāka par ETFP un sintētisko protēzi garu, sarežģītu VCA oklūziju ārstēšanā. ETFP šuntēšana ir alternatīva ar pieņemamu sekundāro caurlaidību, tomēr šī metode prasa daudz vairāk atkārtotu procedūru, lai nodrošinātu vēnai pielīdzināmus rezultātus. Ja šuntēšanai ir pieejama vēna, tai būtu jābūt pirmās izvēles materiālam virs ceļa locītavas šuntēšanas veikšanai. Savukārt šuntēšanu ar sintētisko protēzi vajadzētu lietot tikai gadījumos, kad nav citu efektīvāku ārstēšanas iespēju. Rezultāti liecina, ka labākos novērošanas rezultātus var sasniegt, kombinējot DUS un PBI mērījumus. Šādā veidā var diagnosticēt restenozes. Tās laikus ārstējot, potenciāli iespējams uzlabot ETFP šuntu caurlaidību. Apkopojot rezultātus, mēs secinām, ka ETFP šuntēšana ir izvēles metode situācijās, kad pacientam ir infekcija un nav šuntēšanai derīgas vēnas, kā arī adipoziem pacientiem, pacientiem pēc apstarošanas un iepriekšējas ķirurģiskas iejaukšanās, kas rada rētaudus un apgrūtina vaļējas operācijas izdarīšanu.

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The Impact of Smokeless Tobacco, Nicotine Pouches, and Electronic Cigarettes on Oral Health. Summary of the Doctoral Thesis

(Rīga Stradiņš University, 2025) Miļuna-Meldere, Sintija; Kroiča, Juta; Rostoka, Dagnija

In recent years, new tobacco and nicotine-containing products have emerged that offer colourful designs and a variety of flavours. These products are becoming increasingly popular, not only with traditional tobacco users, but also with new smokers. One of these new nicotine products are nicotine pouches, which resemble smokeless tobacco in appearance and use. Although the sale of smokeless tobacco is prohibited in Latvia, it is widely used, especially among athletes. Nicotine pouches, or smokeless tobacco sachets, are placed under the upper or lower lip and allow the absorption of tobacco, nicotine and other substances through the oral mucosa. As these products do not produce smoke, they are easy to use without disturbing others. Meanwhile, electronic cigarettes are attracting not only current tobacco users, ostensibly to help them to quit smoking, but also individuals who have never used tobacco products before. Unfortunately, disposable electronic cigarettes are widely used by children, leading not only to serious addiction problems but also to health problems requiring hospitalisation. At present, the public and the authorities are under the impression, largely created by these manufacturers, that these new tobacco and nicotine products are a much better alternative to cigarettes and therefore their sale should not be banned. Moreover, such claims are supported by research funded by or associated with these manufacturers. As these products have only recently entered the market, studies on their effects on oral and general health are urgently needed. The aim of this study is to determine the effects of smokeless tobacco products, nicotine pouches and electronic smoking devices on oral microbiota, salivary inflammatory biomarkers and overall oral health. Five scientific articles have been published based on the results of the research and the Thesis will be defended as a series of publications. The research design includes four sections. The first section includes a survey of respondents about general health, oral health habits, diet, lifestyle and use of tobacco and nicotine products. Respondents were selected based on inclusion criteria, followed by oral examinations and the collection of saliva and biofilm samples. The second section includes a histopathological and visual examination of clinical changes in the oral cavity. In the third section, inflammatory biomarkers (IL-1, IL-6, IL-8, TNF-alpha) and LRG-1 in saliva samples are examined. In the fourth section periodontal pathogens and other microorganisms (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Fusobacterium periodonticum, Porphyromonas endodontalis, Rothia mucilaginosa) in saliva, subgingival and supragingival biofilm samples are investigated. The results show that users of smokeless tobacco and nicotine pouches report dry mouth and tingling of the mucous membranes. Users of electronic cigarettes and pouches are prone to bleeding gums, increased plaque build-up, gum recession, altered taste and bad breath. In addition, in areas where pouches are placed, mucosal changes can be seen, clinically characterised as white keratoses of varying roughness and shape. Histological examination of these mucosal samples shows parakeratosis with marked acanthotic mucosal thickening, intraepithelial and connective tissue oedema and a chronic inflammatory infiltrate with lymphocytes and macrophages. Such changes can be defined as mild dysplasia, which is a precancerous condition. In addition, smokeless tobacco and nicotine pouch users who were clinically diagnosed with oral mucosal changes had elevated levels of IL-6 in saliva. Periodontal pathogenic microorganisms are found in the saliva and periodontal pockets of users of electronic cigarettes, smokeless tobacco and nicotine pouches, suggesting that the use of these products may lead to periodontitis. The study data suggest that these products negatively impact oral health and are a serious risk factor for the development of periodontitis and mucosal disease. Furthermore, as these products have only recently entered the market, the long-term effects on oral health are not yet known.

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