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result(s) for
"Lopez-Cano, Manuel"
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A virtual simulation study of the effects of laparotomy incision location and wound stiffness on abdominal wall mechanics
2025
Incisional hernia (IH) is a common complication of laparotomy surgical procedures, influenced by factors such as incision location and surgical wound (SW) tissue strength, and the intra-abdominal pressure (IAP) levels the patient is subject to. In this study we use finite element simulations to investigate how these factors affect the abdominal wall (AW) deformation and the stress distribution on the tissues. Comprehensive geometric models of the AW were generated for five laparotomy incisions, namely midline, paramedian, pararectus, transverse supraumbilical, and subcostal oblique. Finite element simulations for IAP values between 4 and 20 kPa and with the SW tissue strength ranging from very soft to very stiff were conducted using the code Aster open-source software. Simulations revealed that as a general rule laparotomy incisions significantly impact AW mechanics when the SW tissue is soft. In particular, AW mechanics is more sensitive to SW strength in vertical incisions (midline, paramedian, pararectus). The resulting change of the SW dimensions with increasing IAP was also investigated. Softening the SW tissue led to substantial volume increases of the vertical incisions for a given IAP level. In addition, we analyzed stress levels in the SW tissue as well as in the surrounding muscles. A very soft SW may induce the appearance of regions with very high stress levels in the surrounding muscle tissue, heightening their rupture risk. This effect was especially noticeable for the midline incision. On the overall, we found that when the SW tissue is too tender transverse supraumbilical and subcostal incisions present the lowest risk of tissue ruptures whereas the midline incision is the most vulnerable one and the paramedian and pararectus incisions stand midway. In summary, the results of the present simulation provide full support for the clinical guidelines’ recommendation to avoid midline incisions in abdominal surgeries whenever possible.
Journal Article
Balancing mesh-related complications and benefits in primary ventral and incisional hernia surgery. A meta-analysis and trial sequential analysis
by
López-Cano, Manuel
,
Pereira, José Antonio
,
Armengol-Carrasco, Manuel
in
Abdomen
,
Biology and Life Sciences
,
Clinical trials
2018
Primary ventral hernia (PVH) and incisional hernia (IH) repair using a mesh appears to reduce hernia recurrence. However, are the benefits of mesh offset in part by mesh-related complications? The aim of this study was to compare placement of a mesh versus simple suture for recurrence and postoperative complications in the repair of PVH or IH.
Five databases were searched for randomized controlled trials (RCTs). The study population was patients with a PVH or IH undergoing hernia repair. Intervention was placement of a nonabsorbable synthetic mesh, regardless of mesh location, surgical technique, hernia characteristics or surgical setting compared to primary suture. Primary outcome was the incidence of hernia recurrence. Secondary outcomes were wound infection, hematoma, seroma, postsurgical pain, duration of operation, and quality of life. A random-effects meta-analysis with trial sequential analysis (TSA) was used.
10 RCTs with a total of 1270 patients were included. A significant reduction of the incidence of PVH or IH recurrence using a mesh for repair (risk ratio [RR] 0.39, 95% CI 0.27-0.55; P < 0.00001; I2 = 20%) was observed. TSA for recurrence, the accrued information size (1270) was 312% of the estimated required information size (RIS). Subgroup analysis for PVH and IH confirms reduction of recurrence after using a mesh in both groups. Overall postoperative complications did not show statistically significant differences between the mesh and surgical suture groups (RR 1.31, 95% CI 0.94-1.84; P = 0.12; I2 = 27%) but the accrued information size was only 22.4% of RIS and by subgroups complications were only related with IH repair.
Evidence for the efficacy of repair of PVH or IH using a nonabsorbable synthetic mesh in terms of recurrence was found to be robust. Evidence for complications remains inconclusive.
Journal Article
A virtual simulation approach to assess the effect of trocar-site placement and scar characteristics on the abdominal wall biomechanics
by
López-Cano, Manuel
,
López, Josep M.
,
Puigjaner, Dolors
in
639/166/985
,
692/700/565/545/1391
,
Abdomen
2024
Analyses of registries and medical imaging suggest that laparoscopic surgery may be penalized with a high incidence of trocar-site hernias (TSH). In addition to trocar diameter, the location of the surgical wound (SW) may affect TSH incidence. The intra-abdominal pressure (IAP) exerted on the abdominal wall (AW) might also influence the appearance of TSH. In the present study, we used finite element (FE) simulations to predict the influence of trocar location and SW characteristics (stiffness) on the mechanical behavior of the AW subject to an IAP. Two models of laparoscopy patterns on the AW, with trocars in the 5–12 mm range, were generated. FE simulations for IAP values within the 4 kPa–20 kPa range were carried out using the Code Aster open-source software. Different stiffness levels of the SW tissue were considered. We found that midline-located surgical wounds barely deformed, even though they moved outwards along with the regular LA tissue. Laterally located SWs hardly changed their location but they experienced significant variations in their volume and shape. The amount of deformation of lateral SWs was found to strongly depend on their stiffness. Trocar incisions placed in a LA with non-diastatic dimensions do not compromise its mechanical integrity. The more lateral the trocars are placed, the greater is their deformation, regardless of their size. Thus, to prevent TSH it might be advisable to close lateral trocars with a suture, or even use a prosthetic reinforcement depending on the patient's risk factors (e.g., obesity).
Journal Article
Quality Assessment and Risk of Bias of Systematic Reviews of Prophylactic Mesh for Parastomal Hernia Prevention Using AMSTAR and ROBIS Tools
by
López-Cano, Manuel
,
Kroese, Leonard
,
Helgstrand, Frederik
in
Abdominal Surgery
,
Bias
,
Cardiac Surgery
2019
Background
Systematic reviews play a crucial role in clinical decision making and resource allocation and are expected to be unbiased and consistent. The aim of this study is a review of systematic reviews on the use of prophylactic mesh to prevent parastomal hernia (PH) formation using ROBIS and AMSTAR tools to assess the risk of bias and methodological quality.
Methods
We included systematic reviews with or without meta-analysis of which the objective was to assess the use of a prophylactic mesh to prevent PH. A systematic search of the literature in five databases from inception until December 2017 was conducted. For each systematic review, methodologic quality and risk of bias were assessed using the AMSTAR and ROBIS tools, respectively. We estimated the inter-rater reliability for individual domains and for the overall methodological quality and risk of bias using Fleiss’
k
.
Results
We identified 14 systematic reviews that met the inclusion criteria. Using the AMSTAR scale with a cutoff value, six reviews showed high methodologic quality and eight were of low quality. Using the ROBIS tool, the overall risk of bias was low in 50% of the reviews analyzed. In the remaining studies, the risk of bias was unclear.
Conclusions
The global evidence in favor of the use of a prophylactic mesh for preventing PH is not uniform regarding quality and risk of bias. Surgeons cannot be equally confident in the results of all systematic reviews published on this topic.
Journal Article
Virtual simulation of the biomechanics of the abdominal wall with different stoma locations
2022
An ostomy is a surgical procedure by which an artificial opening in the abdominal wall, known as a stoma, is created. We assess the effects of stoma location on the abdominal wall mechanics. We perform three-dimensional finite element simulations on an anatomy model which was generated on the basis of medical images. Our simulation methodology is entirely based on open source software. We consider seventeen different locations for the stoma incision (trephine) and we simulate the mechanical response of the abdominal wall when an intraabdominal pressure as high as 20 kPa is applied. We focus on factors related to the risk of parastomal hernia development such as the deformation experienced by the abdominal wall, the stress levels supported by its tissues and the corresponding level of trephine enlargement. No significant dependence was found between stoma location and the levels of abdominal wall deformations or stress supported by tissues, except for the case with a stoma located on the linea alba. Trephine perimeter and area respectively increased by as much as
44
%
and
85
%
. The level of trephine deformation depends on stoma location with considerably higher trephine enlargements found in stomas laterally located with respect to the rectus abdominis muscle.
Journal Article
A Meta-analysis of Prophylaxis of Surgical Site Infections with Topical Application of Povidone Iodine Before Primary Closure
by
López-Cano, Manuel
,
Balibrea, José
,
Curell, Anna
in
Abdominal Surgery
,
Cardiac Surgery
,
Clinical trials
2019
Background
Povidone iodine (PVI) is a widely used antiseptic solution among surgeons. A meta-analysis based on randomized controlled trials (RCTs) was conducted to establish whether application of PVI before wound closure could reduce surgical site infection (SSI) rates.
Methods
Systematic review of MEDLINE/PubMed, Scopus, CINAHL, and Web of Science databases from inception to September 2017, with no language restrictions. Only RCTs were retrieved. The primary outcome was the SSI rate. Meta-analysis was complemented with trial sequential analysis (TSA).
Results
A total of 7601 patients collected from 16 RCTs were analyzed. A reduction in overall SSI rate was found (RR 0.64, 95% CI 0.48–0.85,
P
= 0.002,
I
2
= 65%), which was attributed to patients undergoing elective operations (
n
= 2358) and mixed elective/urgent operations (
n
= 2019). When RCTs of uncertain quality (
n
= 9) were excluded, the use of PVI before wound closure (
n
= 4322 patients) was not associated with a significant reduction of SSI (RR 0.81, 95% CI 0.55–1.20,
P
= 0.29,
I
2
= 51%) and was only significant in clean wounds (RR 0.25, 95% CI 0.09–0.70,
P
= 0.008,
I
2
= 0%). For the primary outcome, the TSA calculation using a relative risk reduction of 19% and an 11% proportion of control event rate (CER) with 51% of
I
2
, the accrued information size (
n
= 4322) was 32.8% of the estimated optimal information size (
n
= 13,148).
Conclusions
There is no conclusive evidence for a strong recommendation of topical PVI before wound closure to prevent SSI.
Journal Article
Protocol of an interdisciplinary consensus project aiming to develop an AGREE II extension for guidelines in surgery
by
López-Cano, Manuel
,
Francis, Nader K
,
Flórez, Iván D
in
Clinical medicine
,
Clinical practice guidelines
,
Collaboration
2020
IntroductionAppraisal of Guidelines for Research and Evaluation (AGREE II) is an instrument that informs development, reporting and assessment of clinical practice guidelines. Previous research has demonstrated the need for improvement in methodological and reporting quality of clinical practice guidelines specifically in surgery. We aimed to develop an AGREE II extension document for application in surgical guidelines.Methods and analysisWe have performed a structured literature review and assessment of guidelines in surgery using the AGREE II instrument. In exploratory analyses, we have identified factors associated with guideline quality. We have performed reliability and factor analyses to inform the development of an extension document. We will summarise this information and present it to a Delphi panel of stakeholders. We will perform iterative Delphi rounds and we will summarise the final results to develop the extension instrument in a dedicated consensus conference.Ethics and disseminationFunding bodies will not be involved in the development of the instrument. Research ethics committee and Health Research Authority approval was waived, since this is a professional staff study only and no duty of care lies with the National Health Service to any of the participants. Conflicts of interest, if any, will be addressed by reassigning functions or replacing participants with relevant conflicts. The results will be disseminated through publication in peer reviewed journals, the funders’ websites, social media and direct contact with guideline development organisations and peer-reviewed journals that publish guidelines.
Journal Article
AGREE‐S: AGREE II extension for surgical interventions – United European Gastroenterology and European Association for Endoscopic Surgery methodological guide
by
Montendori, Alessandro
,
Florez, Ivan D
,
Brouwers, Melissa
in
AGREE II
,
AGREE‐S
,
Clinical medicine
2022
Background The Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument has been developed to inform the methodology, reporting and appraisal of clinical practice guidelines. Evidence suggests that the quality of surgical guidelines can be improved, and the structure and content of AGREE II can be modified to help enhance the quality of guidelines of surgical interventions. Objective To develop an extension of AGREE II specifically designed for guidelines of surgical interventions. Methods In the tripartite Guideline Assessment Project (GAP) funded by United European Gastroenterology and the European Association for Endoscopic Surgery, (i) we assessed the quality of surgical guidelines and we identified factors associated with higher quality (GAP I); (ii) we applied correlation analysis, factor analysis and the item response theory to inform an adaption of AGREE II for the purposes of surgical guidelines (GAP II); and (iii) we developed an AGREE II extension for surgical interventions, informed by the results of GAP I, GAP II, and a Delphi process of stakeholders, including representation from interventional and surgical disciplines; the Guideline International Network (GIN); the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group; the Enhancing the QUAlity and Transparency Of health Research (EQUATOR) initiative; and representation of surgical journal editors and patient/public. Results We developed AGREE‐S, an AGREE II extension for surgical interventions, which comprises 24 items organized in 6 domains; Scope and purpose, Stakeholders, Evidence synthesis, Development of recommendations, Editorial independence, and Implementation and update. The panel of stakeholders proposed 3 additional items: development of a guideline protocol, consideration of practice variability and surgical/interventional expertise in different settings, and specification of infrastructures required to implement the recommendations. Three of the existing items were amended, 7 items were rearranged among the domains, and one item was removed. The domain Rigour of Development was divided into domains on Evidence Synthesis and Development of Recommendations. The new domain Development of Recommendations incorporates items from the original AGREE II domain Clarity of Presentation. Conclusion AGREE‐S is an evidence‐based and stakeholder‐informed extension of the AGREE II instrument, that can be used as a guide for the development and adaption of guidelines on surgical interventions.
Journal Article
Biological scaffolds in reparative surgery for abdominal wall hernias
by
López-Cano, Manuel
,
Armengol-Carrasco, Manuel
in
Abdomen
,
Abdominal wall
,
Abdominal Wall - surgery
2012
Biological materials derived from human or animal sources are degraded gradually, inducing neovascularization and colonization by host cells that progressively cause a site-specific remodeling process until reconstruction of a new and mature autologous fascia is complete. In this respect, it is difficult to understand why the authors1 decided to use a biological patch in 50% of their patients who had a clean chronic incisional hernia amenable to conventional repair with well-proven synthetic materials. Because evidence...
Journal Article
AGREE-S: AGREE II extension for surgical interventions: appraisal instrument
by
Dayem, Yasser Sami Abdel
,
Florez, Ivan D
,
Brouwers, Melissa
in
Clinical medicine
,
Clinical practice guidelines
,
Consortia
2022
BackgroundThe Appraisal of Guidelines Research and Evaluation (AGREE) II instrument was developed to evaluate the quality of clinical practice guidelines. Evidence suggests that development, reporting, and appraisal of guidelines on surgical interventions may be better informed by modification of the instrument. ObjectiveWe aimed to develop an AGREE II extension specifically designed for appraisal of guidelines of surgical interventions. MethodsIn a three-part project funded by the United European Gastroenterology and the European Association for Endoscopic Surgery, (i) we identified factors that were associated with higher quality of surgical guidelines, (ii) we statistically calibrated the AGREE II instrument in the context of surgical guidelines using correlation, reliability, and factor analysis, and (iii) we undertook a Delphi consensus process of stakeholders to inform the development of an AGREE II extension instrument for surgical interventions. ResultsSeveral features were prioritized by stakeholders as of particular importance for guidelines of surgical interventions, including development of a guideline protocol, consideration of practice variability and surgical expertise in different settings, and specification of infrastructures required to implement the recommendations. The AGREE-S—AGREE II extension instrument for surgical interventions has 25 items, compared to the 23 items of the original AGREE II instrument, organized into the following 6 domains: Scope and purpose, Stakeholders, Evidence synthesis, Development of recommendations, Editorial independence, and Implementation and update. As the original instrument, it concludes with an overall appraisal of the quality of the guideline and a judgement on whether the guideline is recommended for use. Several items were amended and rearranged among domains, and an item was deleted. The Rigor of Development domain of the original AGREE II was divided into Evidence Synthesis and Development of Recommendations. Items of the AGREE II domain Clarity of Presentation were incorporated in the new domain Development of Recommendations. Three new items were introduced, addressing the development of a guideline protocol, support by a guideline methodologist, and consideration of surgical experience/expertise. ConclusionThe AGREE-S appraisal instrument has been developed to be used for assessment of the methodological and reporting quality of guidelines on surgical interventions.
Journal Article