Frailty Increases Morbidity and Mortality in Patients Undergoing Oncological Liver Resections: A Systematic Review and Meta-analysis.

BACKGROUND: Considered to reflect a patients' biological age, frailty is a new syndrome shown to predict surgical outcomes in elderly patients. In view of the increasing age at which patients are proposed oncological liver surgery and the morbidity associated with it, we attempted to perform a systematic review and meta-analysis to compare morbidity and mortality between frail and nonfrail patients after liver resections. METHODS: The study was registered with PROSPERO. A systematic search of PubMed and EMBASE databases was performed for all comparative studies examining surgical outcomes after liver resections between frail and nonfrail patients. RESULTS: Ten studies were included based on the selection criteria with a total of 71,102 patients, split into two groups: frail (n = 17,167) and the control group (n = 53,928). There were more elderly patients with a lower preoperative albumin level in the frail group (p = 0.02, p = 0.001). Frail patients showed higher rates of morbidity with more major complications and a higher incidence of postoperative liver failure (p < 0.001). Mortality (p < 0.001) and readmission rate (p = 0.021) also was higher in frail patients. CONCLUSIONS: Frailty seems to be a solid predictive risk factor of morbidity and mortality after liver surgery and should be considered a selection criterion for liver surgery in at-risk patients.

Conservative surgery versus colorectal resection for endometriosis with rectal involvement: a systematic review and meta-analysis of surgical and long-term outcomes.

PURPOSE: The optimal surgical approach for removal of colorectal endometrial deposits is unclear. Shaving and discoid excision of colorectal deposits allow organ preservation but risk recurrence with associated functional issues and re-operation. Formal resection risks potential higher complications but may be associated with lower recurrence rates. This meta-analysis compares peri-operative and long-term outcomes between conservative surgery (shaving and disc excision) versus formal colorectal resection. METHODS: The study was registered with PROSPERO. A systematic search was performed on PubMed and EMBASE databases. All comparative studies examining surgical outcomes in patients that underwent conservative surgery versus colorectal resection for rectal endometrial deposits were included. The two main groups (conservative versus resection) were compared in three main blocks of variables including group comparability, operative outcomes and long-term outcomes. RESULTS: Seventeen studies including 2861 patients were analysed with patients subdivided by procedure: colorectal resection (n = 1389), shaving (n = 703) and discoid excision (n = 742). When formal colorectal resection was compared to conservative surgery there was lower risk of recurrence (p = 0.002), comparable functional outcomes (minor LARS, p = 0.30, major LARS, p = 0.54), similar rates of postoperative leaks (p = 0.22), pelvic abscesses (p = 0.18) and rectovaginal fistula (p = 0.92). On subgroup analysis, shaving had the highest recurrence rate (p = 0.0007), however a lower rate of stoma formation (p < 0.00001) and rectal stenosis (p = 0.01). Discoid excision and formal resection were comparable. CONCLUSION: Colorectal resection has a significantly lower recurrence rate compared to shaving. There is no difference in complications or functional outcomes between discoid excision and formal resection and both have similar recurrence rates.

Laparoscopic versus open resection of primary colorectal cancers and synchronous liver metastasis: a systematic review and meta-analysis.

PURPOSE: Combined resection of primary colorectal cancer and associated liver metastases is increasingly common. This study compares peri-operative and oncological outcomes according to surgical approach. METHODS: The study was registered with PROSPERO. A systematic search was performed for all comparative studies describing outcomes in patients that underwent laparoscopic versus open simultaneous resection of colorectal primary tumours and liver metastases. Data was extracted and analysed using a random effects model via Rev Man 5.3 RESULTS: Twenty studies were included with a total of 2168 patients. A laparoscopic approach was performed in 620 patients and an open approach in 872. There was no difference in the groups for BMI (mean difference: 0.04, 95% CI: 0.63-0.70, p = 0.91), number of difficult liver segments (mean difference: 0.64, 95% CI:0.33-1.23, p = 0.18) or major liver resections (mean difference: 0.96, 95% CI: 0.69-1.35, p = 0.83). There were fewer liver lesions per operation in the laparoscopic group (mean difference 0.46, 95% CI: 0.13-0.79, p = 0.007). Laparoscopic surgery was associated with shorter length of stay (p < 0.00001) and less overall postoperative complications (p = 0.0002). There were similar R0 resection rates (p = 0.15) but less disease recurrence in the laparoscopic group (mean difference: 0.57, 95% CI:0.44-0.75, p < 0.0001). CONCLUSION: Synchronous laparoscopic resection of primary colorectal cancers and liver metastases is a feasible approach in selected patients and does not demonstrate inferior peri-operative or oncological outcomes.

The mesocolic apical fragment in complete mesocolic excision colectomies: Should it be analysed separately? A proof-of-concept study.

AIM: The aim of this work is to describe a protocol and assess the feasibility of harvesting and analysing the mesocolic apical fragment (MAF) for the presence of central lymph node (LN) metastasis and extra lymphatic free tumour cells in a random subgroup extracted from a cohort of complete mesocolic excision colectomies with central vascular ligation. METHOD: Forty-seven patients diagnosed with colorectal cancer were included. A 2/2 cm pyramid of tissue was cut around the central tie and sent for pathological examination. The MAF was sectioned into 16 slices. High-definition images were taken from the slices which were merged into a panoramic three-dimensional image of the MAF. The distribution of LNs in the MAF was quantified. Immunohistochemistry staining for cytokeratin 14 was used to identify isolated tumour cells and micrometastases in the extranodal tissue. RESULTS: No tumoural cells migrating through the apical zone, outside of the LNs, were identified. Margins of resection, mesocolic tissue and LNs were all negative in the subgroup of ultrastaged MAFs. The number of examined central LNs varied between 0 and 24, with positive MAF LNs being identified only in pN2 stages. The rate of positive apical LNs in our cohort was 4.2% (n = 2). CONCLUSIONS: The MAF can be easily extracted from standard specimens, allowing for accurate analysis of lymphatic and extra-nodal tumour cells on the central resection margins, in central LNs and in the apical mesocolic tissue. Future research on larger cohorts is required to establish if analysing the MAF has an impact on patient staging, prognosis and management.

Evaluation of Changes in Circulating Cell-Free DNA as an Early Predictor of Response to Chemoradiation in Rectal Cancer-A Pilot Study.

Background and Objectives: The objective of this study was to investigate quantitative changes in cell-free DNA (cfDNA) found in the bloodstream of patients with locally advanced rectal cancer who received neoadjuvant long-course chemoradiation, assuming a change in DNA fragments release during therapeutic stress. Materials and Methods: This was a prospective observational study that involved 49 patients who had three distinct pathologies requiring neoadjuvant chemoradiation: 18 patients with breast cancer, 18 patients with cervical cancer, and 13 patients with rectal cancer. Both breast cancer and cervical cancer patients were used as a control groups. Breast cancer patients were used as a control group as irradiation targeted healthy tissue after the tumor resection (R0), while cervical cancer patients were used as a control group to evaluate the effect of chemoradiation regarding cfDNA in a different setting (squamous cell carcinomas) and a different tumor burden. Rectal cancer patients were the study group, and were prospectively evaluated for a correlation between fragmentation of cfDNA and late response to chemoradiation. Blood samples were collected before the initiation of treatment and after the fifth radiation dose delivery. cfDNA was quantified in peripheral blood and compared with the patients' clinicopathological characteristics and tumor volume. Conclusion: Thirteen patients with locally advanced rectal cancer (T3/T4/N+/M0) were included in the study, and all of them had their samples analyzed. Eight were male (61.54%) and five were female (38.46%), with an average age of 70.85 years. Most of the patients had cT3 (53.85%) or cT4 (46.15%) tumors, and 92.31% had positive lymph nodes (N2-3). Of the thirteen patients, only six underwent surgery, and one of them achieved a pathological complete response (pCR). The mean size of the tumor was 122.60 mm3 [35.33-662.60 mm3]. No significant correlation was found between cfDNA, tumor volume, and tumor regression grade. cfDNA does not seem to predict response to neoadjuvant chemoradiotherapy and it is not correlated to tumor volume or tumor regression grade.

Dental Appliances for the Treatment of Obstructive Sleep Apnea in Children: A Systematic Review and Meta-Analysis.

Background and objectives: Obstructive sleep apnea (OSA) in children is a debilitating disease, difficult to treat. Dental appliances have been proposed as a valid therapy for improving functional outcomes with good compliance rates. Herein, we aimed to perform a meta-analysis comparing clinical outcomes between OSA children treated with dental appliances versus controls. Materials Methods: The study was registered with PROSPERO. A systematic search was performed for all comparative studies examining outcomes in pediatric patients who underwent treatment of OSA with oral appliances versus controls. Data was extracted and analyzed using a random effects model via Rev Man 5.3. Results: Six studies including 180 patients were analyzed split into two groups: patients treated with dental appliances (n = 123) and the controls (n = 119). Therapy with dental appliances was shown to significantly improve the apnea-hypopnea index (p = 0.009) and enlarge the superior posterior airway space (p = 0.02). Maxilla-to-mandible measurements were not significantly different between the two groups, nor was the mean SO2 (p = 0.80). Conclusions: This is the most updated meta-analysis assessing the role of dental appliances for OSA in children; it shows that such devices can improve functional outcomes by decreasing the apnea-hypopnea index.

Splenectomy Does Not Increase Early Morbidity in Patients Undergoing Total Gastrectomy: A Case-Control Study with Propensity Score Analysis.

AIM: In gastric cancer (GC), D2 lymph node dissection is, alongside negative-margins gastrectomy, of paramount importance. There is a debate between Western and Eastern scientific communities concerning the risk-benefit balance with respect to splenectomy, as Western countries are inclined to perform spleen-preserving gastrectomy due to an increased risk for postoperative complications. In Eastern countries (such as Japan) this is not the case. Our study aimed to determine whether or not spleen-sacrificing total gastrectomy for GC was associated with a higher rate of early postoperative morbidity or mortality. METHOD: We performed a retrospective case-control study in which we included patients who underwent total gastrectomy with D2 lymphadenectomy for GC (stages I-III) with curative intent, in a single high-volume tertiary oncologic centre. We divided the cases into two groups: spleenpreserving (SP) and spleen-sacrificing (SS) and evaluated the early complications rate following surgery. Afterwards, we performed propensity score matching (PSM) and analysis of the two groups. Results: We included 74 patients, 29 in the SS group and 45 in the SP group. Fifteen cases (20.2%) developed early postoperative complications and the complication rate was 53% (n=8) in the SS group and 46% (n=7) in the SP group. The overall 30-day mortality rate was 2.7%. Conclusions: Splenectomy is not associated with increased early morbidity following total gastrectomy with D2 lymphadenectomy if performed by an experienced surgeon.

Predictive and Prognostic Role of Neutrophil to Lymphocyte Ratio in Rectal Cancer: A Case Control Study with Propensity Score Analysis.

Background: Neutrophil to lymphocyte ratio (NLR) is promoted as a marker reflecting the antitumoral inflammatory response. Herein, we aim to assess whether NLR at the time of diagnosis can predict response to neoadjuvant therapy and long-term survival in a matched cohort of rectal cancer patients. Methods: This is a case control study on rectal cancer patients who underwent standard oncological treatment and had NLR sampled at each stage. ROC curve was used to establish the cut off value of NLR at diagnosis. Two groups (high and low NLR) were compared. Kaplan Meier overall and disease-free survival (DFS) analysis was done comparatively between two groups of patients: low and high NLR. Pearson and Log Rank tests were used to establish statistical significance. Propensity score matching (PSM) was performed, and all variables were compared again on the matched subgroups. Results: One hundred patients were included and 54 were compared again after PSM. NLR at diagnosis did not correlate with tumor regression grade (p=0.77). High NLR at diagnosis (NLR 2.58) was not found to be significantly associated with worse overall survival (p=0.096) or DFS (p=0.128). Similar results were achieved after PSM, except when stage III subgroups were compared, where higher NLR was associated with worse DFS (p=0.04), while results for OS were borderline (p=0.05). Conclusions: Overall, a pretherapeutic high NLR ( 2.58) was not found to predict survival or response do neoadjuvant therapy in patients with rectal cancer. However, a higher NLR may be associated with worse outcomes in advanced colorectal cancer.

Impact of Quilting Sutures on Surgical Outcomes After Mastectomy: A Systematic Review and Meta-Analysis.

BACKGROUND: Seroma after mastectomy and/or axillary lymph node dissection (ALND) is among the most common issue surgeons have to face in the early postoperative management of breast cancer. Using quilting sutures (QS) to aid in tissue approximation and decrease dead space is proposed as a simple technique to reduce seroma rate. We aimed to perform a systematic review, and analyse, in a meta-analytical model, the role of QS in improving wound outcomes and decrease volume, duration of drainage, and length of stay in hospital. METHODS: The study was registered with PROSPERO. A systematic search of the PubMed, EMBASE, and SCOPUS databases was performed for all comparative studies examining surgical outcomes in patients who underwent QS versus conventional closure (CC) after mastectomy ± ALND. RESULTS: Twenty-one studies with a total of 3473 patients (1736 in the study group and 1737 in the control group) were included based on the selection criteria. The study group showed significantly lower rates of seroma (p < 0.00001), total volume of drainage (p < 0.0001), days to drain removal (p < 0.00001), and length of stay (p < 0.00001) compared with the control group, while wound complication rates (surgical site infection, flap necrosis, hematoma, skin dimpling) were comparable between the two groups. CONCLUSIONS: QS are a reliable intraoperative technique that decrease seroma formation, volume of postoperative drainage, duration of drainage and length of hospital stay, and should be considered in mastectomies with or without ALND.

Segmental versus extended colectomy for tumours of the transverse colon: a systematic review and meta-analysis.

AIM: There is no consensus on the appropriate extent of oncological resection for tumours of the transverse colon. Concerns regarding tumour factors such as pattern of lymph node spread and technical factors such as anastomotic perfusion lead to a variety of procedures being performed. METHODS: A comprehensive search for published studies examining outcomes following segmental versus extended colectomy for transverse colon tumours was performed adhering to PRISMA (Preferred Reporting Items in Systematic Reviews and Meta-analyses) guidelines. Random effects methods were used to combine data. RESULTS: Seven comparative series examining outcomes in 3395 patients were identified. Segmental colectomy results in shorter operating times (mean difference 15.80 min, 95% CI -20.98 to -10.62, P < 0.001) and less ileus (OR 0.52, 95% CI 0.33-0.81, P = 0.004). There was no difference in length of hospital stay (mean difference 1.53 days, 95% CI -3.79 to 0.73, P = 0.18). Extended colectomy results in a lower rate of anastomotic leak (OR 0.62, 95% CI 0.40-0.97, P = 0.04). There are fewer nodes retrieved in segmental colectomy (mean difference 7.60 nodes, 95% CI -9.60 to -5.61, P < 0.001) but no difference in disease recurrence (OR 0.88, 95% CI 0.59-1.34, P = 0.56) or overall survival (OR 0.98, 95% CI 0.68-1.4, P = 0.9). CONCLUSIONS: Available data are limited due to a lack of randomized controlled trials. However, based on current evidence, segmental resection for transverse colon tumours is associated with less ileus but lower lymph node yields and higher anastomotic leak rates. Length of stay is similar. Oncological outcomes are equivalent.

New Chimeric Groin Flap: Experimental Model in Rats.

AIM: Increased emphasis is on using tissue substitutes and stem cells to improve flap applicability and survival rates. To accomplish this, the first step is to have a versatile experimental flap, easy to harvest and use as a template. We sought to develop a reliable experimental chimeric groin flap with free mobility and reliable bloods supply that can be twisted, relocated, and integrated easily with other materials. MATERIALS AND METHODS: Ten male Wistar rats were included. The flap consists of a 2.5-cm skin paddle centered on the medial branch of the inferior epigastric artery and a 4.5/2-cm fat pad supplied by the lateral branch of the inferior epigastric artery. After being raised, flaps were resutured in their anatomical position. Flaps were followed up for 15 days. At the end of the study, the viability of flaps was analyzed by ultrahigh-frequency ultrasound, nontargeted contrast study, and histology assessment. RESULTS: All flaps survived without significant complications. Nontargeted microbubbles spread evenly in both the superficial and deep flap. Ultrasound assessment at day 15 showed no significant areas of necrosis or edema. Histology examination of 3 random flaps confirmed vessel patency and flap viability. CONCLUSION: We propose a simple, easy to harvest and reliable experimental flap which offers a main advantage of all-around mobility through its chimeric design. It is a suitable model for bioengineering studies as it can be used as a template for integration of tissue substitutes or stem cells, between its 2 components.

Role of Ultrahigh Frequency Ultrasound in Evaluating Experimental Flaps.

BACKGROUND: Experimental flap follow-up needs faster, safer, and less invasive techniques that can be easily correlated to clinical procedures. For this reason, we aimed to test the role of ultrahigh frequency ultrasound in follow-up of flap viability. Further on, we aimed to analyze if the chimeric groin flap can be mobilized in a sandwiched position without affecting its vascular supply by twisting its pedicle. METHODS: A total of 12 male Wistar rats, split into three groups, were used. Group A (n = 4) had the chimeric groin flap repositioned in a sandwich position on the anterior abdominal wall and underwent ultrahigh frequency ultrasound follow-up at days 10 and 14. Group B (n = 4) also had the flaps sandwiched, however, at day 14 the vascularity of flaps was proven by infusion of nontargeted ultrasound contrast agents, after which flaps were sent for histological analysis. Group C (C1 n = 2, C2 n = 2) was the control group. In C1 the chimeric groin flap was harvested and sent for histology on day 0, acting as a histological benchmark of flap viability, and in C2 the chimeric groin flap was re-sutured in its anatomical position and after 14 days, flaps were harvested and sent for histological analysis, acting as a direct control for Group B. RESULTS: Ultrasound showed constant vascular flow in both adipose and skin flaps in the sandwiched position. Microbubble study showed diffuse perfusion within flaps. Ultrasound measurements of flow velocity, flap volume, and percentage of vascularity showed a decrease in flap volume and increase in vascularity over 14 days. Histology showed similar viability in both groups. CONCLUSION: Ultrahigh frequency ultrasound may be a valuable tool for postoperative flap assessment, while the chimeric flap can be moved freely in a sandwich position making it suitable for adding tissue substitutes within its components.

Postoperative Outcomes and Patient's Satisfaction after Hybrid TIPP with UHS and TEP Repair for Inguinal Hernias: A Single-Centre Retrospective Comparative Study.

Background: Transabdominal Preperitoneal (TAPP) and Totally Extraperitoneal (TEP) inguinal hernia repairs are largely acclaimed for their lower risk of chronic postoperative pain and acceptable recurrence rates. However, hybrid/combined open procedures are still a reliable option among surgeons. Our aim is to compare the outcomes and patients satisfaction of hybrid TIPP (hTIPP) procedure using the Ultrapro Hernia System with laparoscopic pre-peritoneal mesh repair approaches (TEP) to assess its safety and effectiveness. Patients and Methods: The study design is a single center, retrospective comparative study on 90 patients who had hTIPP and TEP inguinal hernia repair in the NAAS General Hospital, over a four-year period (2013-2017). Results: Unplanned postoperative hospital admission was comparable both groups, the figures were 3 patients for hTIPP and 3 patients for TEP. There was no statistically significant difference in the immediate, early and late postoperative pain and complications in both groups. The recurrence rate was nil in hTIPP group compared to one recurrent case in TEP. There is no statistical difference in the five outcomes of the PROM questionnaire and satisfaction rate between hTIPP and TEP. Conclusions: There is no significant difference between hTIPP and TEP in terms of postoperative outcomes and patient satisfaction. hTIPP approach is a safe and feasible alternative to TEP.

Quality assessment of surgery for colorectal cancer: Where do we stand?

Quality assurance in surgery has been one of the most important topics of debate among colorectal surgeons in the past decade. It has produced new surgical standards that led in part to the impressive oncological outcomes we see in many units today. Total mesorectal excision, complete mesocolic excision (CME), and the Japanese D3 lymphadenectomy are now benchmark techniques embraced by many surgeons and widely recommended by surgical societies. However, there are still ongoing discrepancies in outcomes largely based on surgeon performance. This is one of the main reasons why many countries have shifted colorectal cancer surgery only to high volume centers. Defining markers of surgical quality is thus a perquisite to ensure that standards and oncological outcomes are met at an institutional level. With the evolution of CME surgery, various quality markers have been described, mostly based on measurements on the surgical specimen and lymph node yield, while others have proposed radiological markers (i.e. arterial stumps) measured on postoperative scans as part of the routine cancer follow-up. There is no ideal marker; however, taken together and assembled into a new score or set of criteria may become a future point of reference for reporting outcomes of colorectal cancer surgery in research studies and defining subspecialization requirements both at an individual and hospital level.

Assessment of feasibility and safety of cyanoacrylate glue versus absorbable tacks for inguinal hernia mesh fixation. A prospective comparative study.

Introduction: Mesh fixation is one of the most important steps in laparoscopic inguinal hernia repair. Tacks are often used and provide reliable fixation but they increase the risk of bleeding and chronic pain. To decrease chronic pain, absorbable tacks have been more recently developed. Another method is fixation via glue, which is the most minimally invasive approach, but it may theoretically lead to higher rates of fixation failure. Aim: To analyse the intraoperative mesh fixation success rate and postoperative outcomes between cyanoacrylate and absorbable tacks in laparoscopic transabdominal preperitoneal (TAPP) inguinal hernia repair. Material and methods: Adult patients who underwent TAPP hernia repair were included prospectively. Patients were split into two groups: the study group (LB) in which the mesh was fixed with cyanoacrylate glue and the control group (AT) in which absorbable tacks were used. Main outcomes were fixation success rate, early postoperative pain, chronic pain, patient reported outcomes and recurrence rate. Results: The mesh fixation success rate when using LB was 96.70% (n = 88), while in the AT group, the mesh fixation success rate was 100% (n = 120). Patients in the AT group had significantly higher pain scores than patient in the LB group (p < 0.001, 95% CI). There was no significant difference in chronic pain, patient reported outcomes or recurrences between the two groups. Conclusions: Cyanoacrylate glue is a safe option for mesh fixation in transabdominal preperitoneal laparoscopic inguinal hernia repair with improved early postoperative pain and similar chronic pain, patient reported outcomes and recurrence when compared to absorbable tack fixation.

Age, blood tests and comorbidities and AIMS65 risk scores outperform Glasgow-Blatchford and pre-endoscopic Rockall score in patients with upper gastrointestinal bleeding.

BACKGROUND: Upper gastrointestinal (GI) bleeding is a life-threatening condition with high mortality rates. AIM: To compare the performance of pre-endoscopic risk scores in predicting the following primary outcomes: In-hospital mortality, intervention (endoscopic or surgical) and length of admission (≥ 7 d). METHODS: We performed a retrospective analysis of 363 patients presenting with upper GI bleeding from December 2020 to January 2021. We calculated and compared the area under the receiver operating characteristics curves (AUROCs) of Glasgow-Blatchford score (GBS), pre-endoscopic Rockall score (PERS), albumin, international normalized ratio, altered mental status, systolic blood pressure, age older than 65 (AIMS65) and age, blood tests and comorbidities (ABC), including their optimal cut-off in variceal and non-variceal upper GI bleeding cohorts. We subsequently analyzed through a logistic binary regression model, if addition of lactate increased the score performance. RESULTS: All scores had discriminative ability in predicting in-hospital mortality irrespective of study group. AIMS65 score had the best performance in the variceal bleeding group (AUROC = 0.772; P < 0.001), and ABC score (AUROC = 0.775; P < 0.001) in the non-variceal bleeding group. However, ABC score, at a cut-off value of 5.5, was the best predictor (AUROC = 0.770, P = 0.001) of in-hospital mortality in both populations. PERS score was a good predictor for endoscopic treatment (AUC = 0.604; P = 0.046) in the variceal population, while GBS score, (AUROC = 0.722; P = 0.024), outperformed the other scores in predicting surgical intervention. Addition of lactate to AIMS65 score, increases by 5-fold the probability of in-hospital mortality (P < 0.05) and by 12-fold if added to GBS score (P < 0.003). No score proved to be a good predictor for length of admission. CONCLUSION: ABC score is the most accurate in predicting in-hospital mortality in both mixed and non-variceal bleeding population. PERS and GBS should be used to determine need for endoscopic and surgical intervention, respectively. Lactate can be used as an additional tool to risk scores for predicting in-hospital mortality.

Experimental Models for Controlled Burn Injuries in Rats: A Systematic Analysis of Original Methods and Burn Devices.

Despite a wide variety of models found in literature, choosing the right one can be difficult as many of them are lacking precise methodology. This study aims to analyze and compare original burn models in terms of burn device and technique, parameters, and wound depth assessment. A systematic search was performed according to PRISMA guidelines on studies describing original experimental burn models in rats. The adapted PICO formula and ARRIVE checklist were followed for inclusion and assessment of quality of studies. Characteristics of animals, burn technique, burn parameters, and method of histological confirmation of burn depth were recorded. Twenty-seven studies were included in the final analysis. Most studies used direct contact with skin for burn infliction (n = 20). The rat's dorsum was the most common site (n = 18). Ten studies used manually controlled burn devices, while 10 designed automatic burn devices with control over temperature (n = 10), exposure time (n = 5), and pressure (n = 5). Most studies (n = 7) used a single biopsy taken from the center of the wound to confirm burn depth immediately after burn infliction. From the wide variety of burn models in current literature, our study provides an overview of the most relevant experimental burn models in rats aiding researchers to understand what needs to be addressed when designing their burn protocol. Models cannot be compared as burn parameters variate significantly. Assessment of burn depth should be done in a standardized, sequential fashion in future burn studies to increase reproducibility.