1. Ranking as a procedure for selecting a replacement variable in the score predicting the survival of patients treated with curative intent for colorectal liver metastasesIrena Plahuta, Matej Mencinger, Iztok Peruš, Tomislav Magdalenić, Špela Turk, Aleks Brumec, Stojan Potrč, Arpad Ivanecz, 2023, izvirni znanstveni članek Opis: Background and Objectives: The issue of a missing variable precludes the external validation of many prognostic models. For example, the Liverpool score predicts the survival of patients undergoing surgical therapy for colorectal liver metastases, but it includes the neutrophil–lymphocyte ratio, which cannot be measured retrospectively.
Materials and Methods: We aimed to find the most appropriate replacement for the neutrophil–lymphocyte ratio. Survival analysis was performed on data representing 632 liver resections for colorectal liver metastases from 2000 to 2020. Variables associated with the Liverpool score, C-reactive protein, albumins, and fibrinogen were ranked. The rankings were performed in four ways: The first two were based on the Kaplan-Meier method (log-rank statistics and the definite integral ��
between two survival curves). The next method of ranking was based on univariate and multivariate Cox regression analyses.
Results: The ranks were as follows: the radicality of liver resection (rank 1), lymph node infiltration of primary colorectal cancer (rank 2), elevated C-reactive protein (rank 3), the American Society of Anesthesiologists Classification grade (rank 4), the right-sidedness of primary colorectal cancer (rank 5), the multiplicity of colorectal liver metastases (rank 6), the size of colorectal liver metastases (rank 7), albumins (rank 8), and fibrinogen (rank 9).
Conclusions: The ranking methodologies resulted in almost the same ranking order of the variables. Elevated C-reactive protein was ranked highly and can be considered a relevant replacement for the neutrophil–lymphocyte ratio in the Liverpool score. These methods are suitable for ranking variables in similar models for medical research.
Ključne besede: colorectal cancer, liver metastases, inflammation, ranking, survival
Objavljeno v DKUM: 07.04.2025; Ogledov: 0; Prenosov: 11
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2. The learning curve of laparoscopic liver resection utilising a difficulty scoreArpad Ivanecz, Irena Plahuta, Matej Mencinger, Iztok Peruš, Tomislav Magdalenić, Špela Turk, Stojan Potrč, 2022, izvirni znanstveni članek Opis: Background: This study aimed to quantitatively evaluate the learning curve of laparoscopic liver resection (LLR) of a single surgeon.
Patients and methods: A retrospective review of a prospectively maintained database of liver resections was conducted. 171 patients undergoing pure LLRs between April 2008 and April 2021 were analysed. The Halls difficulty score (HDS) for theoretical predictions of intraoperative complications (IOC) during LLR was applied. IOC was defined as blood loss over 775 mL, unintentional damage to the surrounding structures, and conversion to an open approach. Theoretical association between HDS and the predicted probability of IOC was utilised to objectify the shape of the learning curve.
Results: The obtained learning curve has resulted from thirteen years of surgical effort of a single surgeon. It consists of an absolute and a relative part in the mathematical description of the additive function described by the logarithmic function (absolute complexity) and fifth-degree regression curve (relative complexity). The obtained learning curve determines the functional dependency of the learning outcome versus time and indicates several local extreme values (peaks and valleys) in the learning process until proficiency is achieved.
Conclusions: This learning curve indicates an ongoing learning process for LLR. The proposed mathematical model can be applied for any surgical procedure with an existing difficulty score and a known theoretically predicted association between the difficulty score and given outcome (for example, IOC).
Ključne besede: difficulty score, learning curve, laparoscopy, hepatectomy, intraoperative complications, surgical procedures
Objavljeno v DKUM: 07.04.2025; Ogledov: 0; Prenosov: 258
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3. Beljakovinski označevalci vnetja v kliničnem točkovnem sistemu tveganja, ki napoveduje preživetje pri bolnikih po resekciji jetrnih zasevkov raka debelega črevesa in dankeIrena Plahuta, 2024, doktorska disertacija Opis: Izhodišča: Jetrni zasevki raka debelega črevesa in danke so še vedno terapevtski izziv. Poleg zamejitve bolezni in njene resektabilnosti nam pri izboru bolnikov lahko pomagajo klinični točkovni sistemi tveganja. Manjkajoči dejavniki preprečijo uporabo teh sistemov ali onemogočajo njihovo presojo. Liverpoolski točkovnik vsebuje sistemski vnetni odziv, izražen kot razmerje med nevtrofilci in limfociti. Namen raziskave je bil ugotoviti, ali lahko to razmerje nadomestimo z beljakovinskimi označevalci vnetja in dosežemo prognostično veljavnost prilagojenega modela.
Materiali in metode: Retrospektivna klinična raziskava je zajela 371 bolnikov, ki so imeli v letih 2000–2020 prvo resekcijo jetrnih zasevkov raka debelega črevesa in danke. Šest dejavnikov preživetja iz Liverpoolskega točkovnika in tri kandidatne beljakovinske označevalce (C-reaktivni protein, albumin in fibrinogen) smo razvrstili z analizo preživetja po Kaplan-Meierju, integralom Is ter Coxovo uni- in multivariatno regresijsko analizo. Nato smo oblikovali končni Coxov multivariatni regresijski model in z metodo po Kaplan-Meierju izračunali preživetje.
Rezultati: C-reaktivni protein je po vseh štirih metodah razvrščanja na tretjem mestu med devetimi dejavniki preživetja, ima visoko napovedno vrednost in je stabilen v multivariatnih modelih. Povprečno celokupno preživetje bolnikov s povišano vrednostjo C-reaktivnega proteina je krajše za 21,6 meseca. V končnem modelu znaša mediano celokupno preživetje bolnikov 40 mesecev. Mediano celokupno preživetje bolnikov v skupini z nizkim tveganjem je 54 mesecev, v skupini z visokim tveganjem pa 31 mesecev.
Zaključek: C-reaktivni protein lahko nadomesti razmerje med nevtrofilci in limfociti v raziskavah potrjevanja kliničnega točkovnega sistema tveganja, ki napoveduje preživetje bolnikov po resekciji jetrnih zasevkov raka debelega črevesa in danke.
Ključne besede: Rak debelega črevesa in danke, jetrni zasevki, vnetni odziv, preživetje, razvrščanje
Objavljeno v DKUM: 17.05.2024; Ogledov: 359; Prenosov: 56
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4. Achievements in surgical treatment for colorectal liver metastases from 2000 until 2020Irena Plahuta, Tomislav Magdalenić, Špela Turk, Stojan Potrč, Arpad Ivanecz, 2022, izvirni znanstveni članek Ključne besede: colorectal cancer, liver metastases, hepatectomy, survival
Objavljeno v DKUM: 17.01.2023; Ogledov: 537; Prenosov: 58
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