Undetectable circulating tumor DNA confirms the inability of pseudomyxoma peritonei to systemic dissemination.

The study of circulating tumor DNA (ctDNA) plays a pivotal role in advancing precision oncology, providing valuable information for individualized patient care and contributing to the ongoing effort to improve cancer diagnosis, treatment, and management. However, its applicability in pseudomyxoma peritonei (PMP) remains unexplored. In this multicenter retrospective study involving 21 PMP patients, we investigated ctDNA presence in peripheral blood using three distinct methodologies. Despite mucinous tumor tissues exhibiting KRAS and GNAS mutations, ctDNA for these mutations was undetectable in blood samples. In this pilot study, circulating tumor DNA was not detected in blood when the tumor harbored mutations of known significance. In the future, a study with a larger sample size is needed to confirm these findings and to determine whether ctDNA could identify patients at risk for early recurrence and/or systemic metastases.

Therapeutic effect of adipose-derived mesenchymal stem cells in a porcine model of abdominal sepsis.

BACKGROUND: The term sepsis refers to a complex and heterogeneous syndrome. Although great progress has been made in improving the diagnosis and treatment of this condition, it continues to have a huge impact on morbidity and mortality worldwide. Mesenchymal stem cells are a population of multipotent cells that have immunomodulatory properties, anti-apoptotic effects, and antimicrobial activity. We studied these capacities in a porcine model of peritoneal sepsis. METHODS: We infused human adipose-derived mesenchymal stem cells (ADSCs) into a porcine model of peritoneal sepsis. Twenty piglets were treated with antibiotics alone (control group) or antibiotics plus peritoneal infusion of ADSCs at a concentration of 2 × 106 cells/kg or 4 × 106 cells/kg (low- and high-dose experimental groups, respectively). The animals were evaluated at different time points to determine their clinical status, biochemical and hematologic parameters, presence of inflammatory cytokines and chemokines in blood and peritoneal fluid, and finally by histologic analysis of the organs of the peritoneal cavity. RESULTS: One day after sepsis induction, all animals presented peritonitis with bacterial infection as well as elevated C-reactive protein, haptoglobin, IL-1Ra, IL-6, and IL-1b. Xenogeneic ADSC infusion did not elicit an immune response, and peritoneal administration of the treatment was safe and feasible. One day after infusion, the two experimental groups showed a superior physical condition (e.g., mobility, feeding) and a significant increase of IL-10 and TGF-ß in blood and a decrease of IL-1Ra, IL-1b, and IL-6. After 7 days, all animals treated with ADSCs had better results concerning blood biomarkers, and histopathological analysis revealed a lower degree of inflammatory cell infiltration of the organs of the peritoneal cavity. CONCLUSIONS: Intraperitoneal administration of ADSCs as an adjuvant therapy for sepsis improves the outcome and diminishes the effects of peritonitis and associated organ damage by regulating the immune system and reducing intra-abdominal adhesions in a clinically relevant porcine model of abdominal sepsis.

PRESS survey: PREvention of surgical site infection-a global pan-specialty survey of practice protocol.

Background: Surgical site infections (SSI) complicate up to 40% of surgical procedures, leading to increased patient morbidity and mortality. Previous research identified disparities in SSI prevention guidelines and clinical practices across different institutions. The study aims to identify variations in SSI prevention practices within and between specialties and financial systems and provide a representation of existing SSI preventative measures to help improve the standardization of SSI prevention practices. Methods: This collaborative cross-sectional survey will be aimed at pan-surgical specialties internationally. The study has been designed and will be reported in line with the CROSS and CHERRIES standards. An international study steering committee will design and internally validate the survey in multiple consensus-based rounds. This will be based on SSI prevention measures outlined in the CDC (2017), WHO (2018), NICE (2019), Wounds UK (2020) and the International Surgical Wound Complications Advisory Panel (ISWCAP) guidelines. The questionnaire will include demographics, SSI surveillance, preoperative, peri-operative and postoperative SSI prevention. Data will be collected on participants' surgical specialty, operative grade, of practice and financial healthcare system of practice. The online survey will be designed and disseminated using QualtricsXM Platform™ through national and international surgical colleges and societies, in addition to social media and snowballing. Data collection will be open for 3 months with reminders, and raking will be used to ascertain the sample. Responses will be analyzed, and the chi-square test used to evaluate the impact of SSI prevention variables on responses. Discussion: Current SSI prevention practice in UK Vascular surgery varies considerably, with little consensus on many measures. Given the inconsistency in guidelines on how to prevent SSIs, there is a need for standardization. This survey will investigate the disparity in SSI preventative measures between different surgical fields and countries.

Surgical management of complex perianal fistula revisited in a systematic review: a critical view of available scientific evidence.

BACKGROUND: Treating complex perianal fistulas in Crohn's disease patients remains a challenge. Classical surgical treatments for Crohn's disease fistulas have been extrapolated from cryptoglandular fistulas treatment, which have different etiology, and this might interfere with its effectiveness, in addition, they increase fecal incontinence risk. Recently, new surgical techniques with support from biological approaches, like stem cells, have been developed to preserve the function of the sphincter. We have performed a systematic literature review to compare the results of these different techniques in the treatment of Crohn's or Cryptoglandular fistula. METHODS: PubMed, EMBASE, Database of Abstracts of Reviews of Effectiveness, Cochrane Central Register of Controlled Trials were searched systematically for relevant articles. We included randomized controlled trials and observational studies that referred to humans, were written in English, included adults 18+ years old, and were published during the 10-year period from 2/01/2010 to 2/29/2020. Evidence level was assigned as designated by the Scottish Intercollegiate Guidelines Network. RESULTS: Of the 577 citations screened, a total of 79 were ultimately included in our review. In Crohn's disease patients, classical techniques such as primarily seton, Ligation of Intersphincteric Fistula Tracks, or lay open, healing rates were approximately 50-60%, while in cryptoglandular fistula were around, 70-80% for setons or flaps. In Crohn's disease patients, new surgical techniques using derivatives of adipose tissue reported healing rates exceeding 70%, stem cells-treated patients achieved higher combined remission versus controls (56.3% vs 38.6%, p = 0.010), mesenchymal cells reported a healing rate of 80% at week 12. In patients with cryptoglandular fistulas, a healing rate of 70% using derivatives of adipose tissue or platelets was achieved, and a healing rate of 80% was achieved using laser technology. Fecal incontinence was improved after the use of autologous platelet growth factors and Nitinol Clips. CONCLUSION: New surgical techniques showed better healing rates in Crohn's disease patients than classical techniques, which have better results in cryptoglandular fistula than in Crohn's disease. Healing rates for complex cryptoglandular fistulas were similar between the classic and new techniques, being the new techniques less invasive; the incontinence rate improved with the current techniques.

Toxicity study in a pig model of intraperitoneal collagenase as an "enzymatic scalpel" directed to break stroma in order to generate a new perspective for peritoneal carcinomatosis approach: an experimental research.

BACKGROUND: This study aimed to measure the toxicity resulting from collagenase administration to the peritoneal cavity in a pig model as a preliminary step to break down the stroma surrounding tumors. METHODS: Eight pigs were treated with 2 different collagenase concentrations previously tested in rats by our group. Time and temperature were controlled using a peritoneal lavage system (PRS System, Combat Medical Ltd.) identical to that used in human surgeries through hyperthermic intraperitoneal chemotherapy (HIPEC); 2 additional pigs were treated with peritoneal lavage only. Samples of blood and peritoneal fluid were collected pre-treatment, immediately after treatment, and 24 h postoperatively. In addition, histological studies and blood collagenase levels were measured. RESULTS: No complications were observed during the surgeries. Intraoperative images evidenced the release of peritoneal tissue during collagenase treatment. After surgery, the animals showed no signs of pain. Diet and mobility were normal at 4 h postoperatively, and there were no significant differences in hematologic or biochemical parameters. Quantification of MMP1 and MMP2 in all samples as measured by absorbance showed no differences in blood collagenase levels between pre-treatment, post-treatment, and 24 h postoperatively. None of the animals treated with collagenase showed peritoneal adhesions during the second surgery. Histologically, peritoneal organs and serous structures did not show any microscopic alterations associated with collagenase treatment in any group. CONCLUSION: Lavage of the peritoneal cavity with doses of up to 100,000 collagen digestion units/animal for 30 min is safe and removes connective tissue from the peritoneal cavity.

The SARS-CoV-2 first wave impact in the acute inflammatory surgical pathologies.

Anecdotal evidence suggests that community infection control measures during the COVID-19 outbreak have modified the number and natural history of acute surgical inflammatory processes (ASIP-appendicitis, cholecystitis, diverticulitis and perianal abscesses) admissions. This study aims to evaluate the impact of the COVID-19 pandemic on the presentation and treatment ASIP and quantify the effect of COVID-19 infection on the outcomes of ASIP patients. This was a multicentre, comparative study, whereby ASIP cases from 2019, 2020 and 2021 (March 14th to May 2nd) were analyzed. Data regarding patient and disease characteristics as well as outcomes, were collected from sixteen centres in Madrid, and one in Seville (Spain). The number of patients treated for ASIP in 2019 was 822 compared to 521 in 2020 and 835 in 2021. This 1/3rd reduction occurs mainly in patients with mild cases, while the number of severe cases was similar. Surgical standards suffered a step back during the first wave: Lower laparoscopic approach and longer length of stay. We also found a more conservative approach to the patients this year, non-justified by clinical circumstances. Luckily these standards improved again in 2021. The positive COVID-19 status itself did not have a direct impact on mortality. Strikingly, none of the 33 surgically treated COVID positive patients during both years died postoperatively. This is an interesting finding which, if confirmed through future research with a larger sample size of COVID-19 positive patients, can expedite the recovery phase of acute surgical services.

Intraperitoneal collagenase as a novel therapeutic approach in an experimental model of colorectal peritoneal carcinomatosis.

The usefulness of local collagenase in therapeutic approaches to solid tumors has been tested recently. In this study, we evaluate the safety and efficacy of intraperitoneal collagenase associated or not to mitomycin for treatment of colorectal peritoneal metastases in an experimental rat model. Using a fixed-dose procedure, we found that a dose of collagenase of 37 IU/mL administered for 15 min with a hyperthermia pump at 37.5 °C, both in isolation or associated to sequential treatment with intraperitoneal mitomycin, led to a macroscopic decrease in tumor volume as evaluated by the modified peritoneal cancer index (mPCI). Concerning the safety of the procedure, the animals showed no physiological or behavioral disorders during 8 weeks of follow-up. Local treatment for peritoneal metastases of colorectal origin with intraperitoneal collagenase has proved safe and effective in an experimental murine model. Therefore, the stroma-first approach by enzymatic breakdown of collagen from the tumor's extracellular matrix provides a new therapeutic target for colorectal peritoneal metastases.

Mesenchymal stem cells in perianal Crohn's disease.

The use of mesenchymal stem cells has resulted in a breakthrough for the treatment of complex perianal fistulas in Crohn's disease. This novel treatment is associated with a minimally invasive surgical technique that can be well defined. However, our previous experience has taught us that neglecting any of the critical steps in the operation can result in frequent treatment failure. We have put together a comprehensive guide, a stepwise algorithm, for our minimally invasive approach to identify common pitfalls and reduce treatment failures. Using data we have collected over the past 15 years from drug development, execution of clinical trials, and enacting an advanced educational training program, we spelt out each stage of the minimally invasive surgical intervention for stem cell delivery for perianal Crohn's disease. In this article, we provide 21 tips for a correct approach during the five major phases of the surgical procedure. To optimize the efficacy of mesenchymal stem cells for perianal Crohn's disease, a standardized minimally invasive technique including a reliable and reproducible series of key steps should be utilized.

A First Step to a Biomarker of Curative Surgery in Colorectal Cancer by Liquid Biopsy of Methylated Septin 9 Gene.

OBJECTIVES: To confirm that patients affected by colorectal cancer have the V2 region of Septin 9 (SEPT9) gene hypermethylated in the circulating free DNA from a peripheral blood sample before surgery and to determine if this hypermethylated DNA disappears from the patients after complete resection of the tumour. METHODS: Plasma from 10 patients with colorectal cancer was collected preoperative and three months after surgery. The analysis of the methylation status of the promoter region of the SEPT9 gene was performed using a 7500 Fast Real-Time PCR System. RESULTS: Hypermethylation of SEPT9 gene was detected in 8 out of 10 preoperative samples (one negative result was probed to be a Lynch syndrome) and in 4 out of 10 postoperative samples matching with the cases of recurrence or persistence of disease. This means that, in this sample, the preoperative sensitivity and specificity of the test were 88.9% and 100%, respectively, and there is 100% correlation between the positive results of the SEPT9 test and a recurrence/persistence of the disease in patients after surgical resection. CONCLUSIONS: Our study shows that circulating hypermethylated SEPT9 is a specific colorectal cancer biomarker. This hypermethylated SEPT9 DNA disappears around three months after surgery and that circulating hypermethylated SEPT9 may be the first noninvasive marker for postsurgical diagnosis; this conclusion must be confirmed with a more significant number of patients.

Stem Cell Therapy: A Compassionate Use Program in Perianal Fistula.

AIM: To report our experience in a compassionate use program for complex perianal fistula. METHODS: Under controlled circumstances and approved by European and Spanish laws, a compassionate use program allows the use of stem cell therapy for patients with nonhealing diseases, mostly complex fistula-in-ano, who do not meet criteria to be included in a clinical trial. Candidates had previously undergone multiple surgical interventions that had failed. The intervention consisted of surgery (with closure of the internal opening or a surgical flap performance), followed by stem cell injection. Three types of cells were used for implant: stromal vascular fraction, autologous expanded adipose-derived, or allogenic adipose-derived stem cells. Healing was evaluated at 6th month follow-up. Outcome was classified as partial response or healing. Relapse was evaluated 1 year later. Maximum follow-up period was 48 months. RESULTS: 45 patients (24 male) were included; the mean age was 45 years, which ranged from 24 to 69 years. Since some of them received repeated doses, 52 cases were considered (42 fistula-in-ano, 7 rectovaginal fistulas, 1 urethrorectal fistula, 1 sacral fistula, and 1 hidradenitis suppurativa). Regarding fistula-in-ano, there were 18 Crohn's-associated and 24 cryptoglandular. 49 cases (94.2%) showed partial response starting 6.5 weeks of follow-up. 24 cases (46.2%) healed in a mean time of 5.5 months. A year later, all patients cured remained healed. No adverse effects related to stem cell therapy were reported. CONCLUSION: Stem cells are safe and useful for treating anal fistulae. Healing can be achieved in severe cases.

Objective demonstration of improvement of neurogenic bowel dysfunction in a case of spinal cord injury following stem cell therapy.

Constipation in spinal cord injury patients is a frequent complication that leads to a reduction of quality of life, extensive psychological and economic strain on patients and healthcare systems. We report a 58-year-old man with an incomplete SCI secondary to L1 vertebral fracture, presented gait disorder with neurogenic bowel and bladder dysfunction. He received 300 million autologous mesenchymal stromal cells (MSC) in the subarachnoid space by lumbar puncture. After the third administration of MSC the patient had an important improvement in almost every functional scale of spinal cord injury, especially in the Krogh's Neurogenic Bowel Dysfunction scale. Our present observation supports recent clinical findings about the benefit of autologous stem cell therapy for the improvement of bowel dysfunction in patients suffering spinal cord injury.

A Step-By-Step Surgical Protocol for the Treatment of Perianal Fistula with Adipose-Derived Mesenchymal Stem Cells.

Anal fistula is a challenging condition both for surgeons and patients. Recurrent fistula, Crohn's disease, or autoimmune disorders add further complexity to this situation. Numerous clinical trials have now demonstrated that cell-based therapy appears to be a good complement to fistulous surgery. As in any new treatment, especially that involving living cells, appropriate application is paramount to achieve optimal outcomes. As stem cell-based treatments are gaining a strong foothold in fistula management worldwide, we herein aim to share our mesenchymal stem cell surgical protocol. With the goal of optimizing results of this emerging therapy, we have improved and refined our protocol over the past 17 years of working with stem cells in clinical trials. The protocol consists of nine reproducible steps for mesenchymal stem cell application inside the fistulous tract, and has proven to be safe and effective in several studies, including international phase III clinical trials.

Histopathological factors predicting response to neoadjuvant therapy in gastric carcinoma.

BACKGROUND: Neoadjuvant therapy (NAT) is a useful therapeutic option. However, some patients respond poorly to it and can even show tumor progression. It is important to define factors that can predict response to NAT. MATERIALS AND METHODS: This is a retrospective cohort study to define histopathological factors predicting response to NAT in gastric tubular carcinoma. This study has enrolled 80 patients receiving chemotherapy for locally advanced gastric carcinoma. RESULTS: 44.5% of the patients were men; mean age was 64.49 years. Only 5.7% of the patients showed a complete response to therapy, 10% had grade 1, 21.4% grade 2, and 62.9% grade 3 regression. On follow-up, 43.8% of the patients showed recurrence of disease (57.1% distant metastasis) and 33.8% eventually died of it. We found a statistically significant association between response and prognosis. We found a statistically significant association between regression and perineural, vascular, and lymph vessel invasion. Logistic regression model showed that only lymph vessel invasion had independent influence. Lymph vessel invasion not only indicated lack of response to therapy, but also higher incidence of lymph node involvement in the gastrectomy specimen. DISCUSSION: Our study indicates that the presence of vascular or perineural invasion in the endoscopic biopsies and high histopathological grade predict poor response to therapy. This seems peculiar, for undifferentiated tumors are supposed to have better response to therapy. CONCLUSION: Our study indicates that undifferentiated tumors respond worse to therapy. Furthermore, studies are necessary to define lack of response, to help avoid neoadjuvant therapy in unfavorable cases.

Combined abdomino-sacral laparoscopically assisted approach for retrorectal mass resection in a patient with Currarino's Syndrome - video vignette.

A correct preoperative strategy is crucial when surgery is needed for retrorectal tumours (RRT).[1] Surgical approaches may be purely anterior-abdominal, posterior-sacrococcygeal or combined depending on the tumour's size and location.[2] We present the case of an 18-year-old female with Currarino Syndrome who underwent surgery by a combined abdominal laparoscopic-posterior Kraske approach for the resection of a large RRT. This article is protected by copyright. All rights reserved.

Potential of mesenchymal stem cell in stabilization of abdominal aortic aneurysm sac.

BACKGROUND: In their origin, abdominal aortic aneurysms (AAAs) are related to an inflammatory reaction within the aortic wall, which can lead to weakness and degeneration of this structure. One of the most widely accepted treatment modalities for AAAs is the placement of stent grafts. Nevertheless, in some patients blood re-enters the aneurysm sac, creating so-called leaks, which constitute a renewed risk of rupture and death.This study explores the possibility of filling aneurysm sacs treated by endovascular aneurysm repair with adipose tissue-derived mesenchymal stem cells (ASCs) in a porcine model. METHODS: We developed a porcine model using 22 animals by creating an artificial AAA made with a Dacron patch. AAAs were then treated with a coated stent that isolated the aneurysm sac, after which we introduced allogeneic ASC into the sac. Animals were followed-up for up to 3 mo. The experiment consisted of the aforementioned surgical procedure performed first, followed by computed tomography and echo-Doppler imaging during the follow-up, and finally, after sacrificing the animals, histologic analysis of tissue samples from the site of cell implantation by a blinded observer and the detection of implanted cells by immunofluorescence detection of the Y chromosome. RESULTS: Our findings demonstrate the survival of ASCs over the 3 mo after implantation and histologic changes associated with this treatment. Treated animals had less acute and chronic inflammation throughout the study period, and we observed increasing fibrosis of the aneurysm sac, no accumulation of calcium, and a regeneration of elastic fibers in the artery. CONCLUSIONS: The combination of endovascular aneurysm repair and cell therapy on AAAs has promising results for the stabilization of the sac, resulting in the generation of living tissue that can secure the stent graft and even showing some signs of wall regeneration. The therapeutic value of such cell-based therapy will require further investigation.

Anaesthetic effects in the ferret of alfaxalone alone and in combination with medetomidine or tramadol: a pilot study.

Alfaxalone is a neurosteroid with anaesthetic effects and it has been used successfully in several animal species. However, there are no data, to our knowledge, about its efficacy and safety in ferrets (Mustela putorius furo). We evaluated a variety of anaesthetic regimens in ferrets, namely, alfaxalone at 20, 10 and 5 mg/kg (n = 1, 10 and 9, respectively; intravenously); medetomidine at 20 µg/kg (n = 3; intramuscularly); medetomidine (20 µg/kg, intramuscularly) plus alfaxalone (2.5 mg/kg, intravenously; n = 7); and tramadol (5 mg/kg, intramuscularly) plus alfaxalone (5 mg/kg, intravenously; n = 2). Two animals treated with alfaxalone at 10 mg/kg and 20 mg/kg, respectively, died. At 5 mg/kg alfaxalone produced anaesthesia with a similar onset but a shorter duration of anaesthesia and analgesia than alfaxalone at 10 mg/kg. The medetomidine-alfaxalone combination produced anaesthesia and analgesia of a longer duration than alfaxalone administered alone at 5 mg/kg (P < 0.0001 and P < 0.001, respectively). Under this anaesthetic regimen, there was a progressive decrease in pulse rate during the first 30 min before the pulse rate stabilized. Respiratory parameters were maintained at acceptable levels. When tramadol was administered, all the animals exhibited a strong excitation reaction and in no case was the toe-pinch reflex clearly abolished. Thus, alfaxalone plus medetomidine provided safe and effective anaesthesia in ferrets. Alfaxalone, alone or in combination with tramadol, did not produce satisfactory results for use as an anaesthetic for this species.