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-β 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.

An international consensus for mitigation of the detrimental effects of the COVID-19 pandemic on laparoscopic training

Aim

Achieve an international consensus on how to recover lost training opportunities. The results of this study will help inform future EAES guidelines about the recovery of surgical training before and after the pandemic.

Background

A global survey conducted by our team demonstrated significant disruption in surgical training during the COVID-19 pandemic. This was wide-spread and affected all healthcare systems (whether insurance based or funded by public funds) in all participating countries. Thematic analysis revealed the factors perceived by trainees as barriers to training and gave birth to four-point framework of recovery. These are recommendations that can be easily achieved in any country, with minimal resources. Their implementation, however, relies heavily on the active participation and leadership by trainers. Based on the results of the global trainee survey, the authors would like to conduct a Delphi-style survey, addressed to trainers on this occasion, to establish a pragmatic step-by-step approach to improve training during and after the pandemic.

Methods

This will be a mixed qualitative and quantitative study. Semi-structured interviews will be performed with laparoscopic trainers. These will be transcribed and thematic analysis will be applied. A questionnaire will then be proposed; this will be based on both the results of the semi structured interviews and of the global trainee survey. The questionnaire will then be validated by the steering committee of this group (achieve consensus of >80%). After validation, the questionnaire will be disseminated to trainers across the globe. Participants will be asked to consent to participate in further cycles of the Delphi process until more than 80% agreement is achieved.

Results

This study will result in a pragmatic framework for continuation of surgical training during and after the pandemic (with special focus on minimally invasive surgery training).

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.

Stem cell therapy applied for digestive anastomosis: Current state and future perspectives

BACKGROUND

Digestive tract resections are usually followed by an anastomosis. Anastomotic leakage, normally due to failed healing, is the most feared complication in digestive surgery because it is associated with high morbidity and mortality. Despite technical and technological advances and focused research, its rates have remained almost unchanged the last decades. In the last two decades, stem cells (SCs) have been shown to enhance healing in animal and human studies; hence, SCs have emerged since 2008 as an alternative to improve anastomoses outcomes.

AIM

To summarise the published knowledge of SC utilisation as a preventative tool for hollow digestive viscera anastomotic or suture leaks.

METHODS

PubMed, Science Direct, Scopus and Cochrane searches were performed using the key words “anastomosis”, “colorectal/colonic anastomoses”, “anastomotic leak”, “stem cells”, “progenitor cells”, “cellular therapy” and “cell therapy” in order to identify relevant articles published in English and Spanish during the years of 2000 to 2021. Studies employing SCs, performing digestive anastomoses in hollow viscera or digestive perforation sutures and monitoring healing were finally included. Reference lists from the selected articles were reviewed to identify additional pertinent articles.

Given the great variability in the study designs, anastomotic models, interventions (SCs, doses and vehicles) and outcome measures, performing a reliable meta-analysis was considered impossible, so we present the studies, their results and limitations.

RESULTS

Eighteen preclinical studies and three review papers were identified; no clinical studies have been published and there are no registered clinical trials. Experimental studies, mainly in rat and porcine models and occasionally in very adverse conditions such as ischaemia or colitis, have been demonstrated SCs as safe and have shown some encouraging morphological, functional and even clinical results. Mesenchymal SCs are mostly employed, and delivery routes are mainly local injections and cell sheets followed by biosutures (sutures coated by SCs) or purely topical. As potential weaknesses, animal models need to be improved to make them more comparable and equivalent to clinical practice, and the SC isolation processes need to be standardised. There is notable heterogeneity in the studies, making them difficult to compare. Further investigations are needed to establish the indications, the administration system, potential adjuvants, the final efficacy and to confirm safety and exclude definitively oncological concerns.

CONCLUSION

The future role of SC therapy to induce healing processes in digestive anastomoses/sutures still needs to be determined and seems to be currently far from clinical use.

EP.FRI.451 Laparotomy rates and factors influencing treatment modality for diverticulitis during the COVID-19 lockdown

Background

Infection control measures during the COVID-19 crisis modified diverticulitis treatment. Here we present the treatment applied in three large UK centres compared to the same timeframe in 2019. 

Methods

This was a multicentre, comparative study, whereby diverticulitis cases from March 23^rdto May 11^th2019 acted as historical controls for cases during lockdown. Severity at presentation (SD), comorbidities, treatment modality, Length of Stay (LOS), complications and COVID-19 status (CS) were recorded. Chi-squared, ANOVA, Mann-Whitney test and linear regression were used for analyses. 

Results

59 patients presented with diverticulitis in 2020 compared to 130 in 2019 (M:F 27/32, 56/74 and 64vs.62 y.o.). Laparotomy was performed in 6/59 and 12/130 respectively. Comparing 2019 to 2020, there was no statistical difference for severity (p = 0.643), treatment modality (0.946), comorbidities (0.313), LOS (0.602). Linear regression demonstrated statistically significant association between treatment employed (p < 0.001) and SD, while there was no association with age, comorbidities or CS. LOS was associated with severity only (p < 0.001), whilst CS, treatment, age and comorbidities yielded no statistical difference. 

Conclusion

Diverticulitis cases during 2020 lockdown reduced noticeably (59vs.130). There was no difference in severity, treatment, comorbidities or LOS between 2019 and 2020. Laparotomy was performed in 6/59 and 12/130 respectively. Decision about treatment and LOS in 2020 was associated with severity of disease only. There was no association with COVID status. These findings should be interpreted with caution due to small COVID positive numbers and not including ambulatory units, however, they are consistent with findings from our sister Spanish group.    

Implementation barriers for Enhanced Recovery After Surgery (ERAS) in rectal cancer surgery: a comparative analysis of compliance with colon cancer surgeries

We aim to analyze differences in compliance between colon and rectal cancer surgeries under Enhanced Recovery After Surgery (ERAS) for colorectal procedures, and to detect implementation barriers for rectal cancer surgeries. Patients who underwent elective rectal cancer surgeries under ERAS were case-matched based on gender, age, and P-POSSUM with an equal number of patients who underwent colonic surgeries. Achievements of ≥ 70% of ERAS items were considered an acceptable level of compliance. A multivariate analysis was carried out to identify independent risk factors for lower compliance. A total of 434 patients were included over a 5-year period. After matching, there were 111 patients in each group. Overall compliance was significantly lower in the rectal surgery group (73% vs 82%, p = 0.001). A good compliance rate differed from 55% in rectal vs 77.5% in colonic procedures (p = 0.000). We identified three independent risk factors for lower compliance rates: open surgical approach, the use of epidural catheter, and the presence of postoperative ileus. Our data showed that rectal cancer surgeries are more exigent to success on ERAS interventions when compared to colonic resections. There is a need to introduce specific modifications on the protocols for colorectal surgeries when applied to these particular procedures.

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.

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.

Short-term outcomes and benefits of ERAS program in elderly patients undergoing colorectal surgery: a case-matched study compared to conventional care

PURPOSE

The aim of the study was to evaluate the benefits of implementing Enhanced Recovery After Surgery (ERAS) protocols in elderly patients undergoing elective colorectal surgery.

METHODS

A retrospective non-randomized cohort study was conducted from September 2012 to December 2016. We included patients ≥ 70 years undergoing elective colorectal surgery. Outcome measures, compliance with interventions, and postoperative complications of patients treated under ERAS were case-matched (based on gender, age, type of surgery, and the presence/absence of a temporal stoma) to a retrospective group of patients ≥ 70 years treated under conventional care.

RESULTS

A total of 312 patients (156 ERAS vs. 156 non-ERAS) were included in the study. The ERAS group had a significant reduction of grade III/IV Dindo-Clavien's postoperative complications when compared with conventional care. ERAS had a positive effect in reducing anastomotic leakage (14.7% non-ERAS vs. 9%) and postoperative mortality (11.5% non-ERAS vs. 1.9% ERAS; p = 0.001). A reduction of 2 days in length of hospital stay was achieved after implementing ERAS (8 (6.75) vs. 6 (5.25); p < 0.0001), while readmission rates remained unaffected. The average of global compliance (GC) with all ERAS interventions was 42%. GC was significantly lower in patients with permanent/temporary stomas and in patients in whom an open approach was performed.

CONCLUSION

In our experience, ERAS should be implemented without reservations in elderly patients expecting the same goals and benefits as with other age groups. Barriers in achieving a high compliance rate are common and will require a great effort in patient's education, an intensive perioperative care, and sometimes a change in the surgeons' practice.

Cell therapy with autologous mesenchymal stromal cells in post-traumatic syringomyelia

BACKGROUND AIMS

Recently, clinical studies show that cell therapy with mesenchymal stromal cells (MSCs) improves the sequelae chronically established in paraplegic patients, being necessary to know which of them can obtain better benefit.

METHODS

We present here a phase 2 clinical trial that includes six paraplegic patients with post-traumatic syringomyelia who received 300 million MSCs inside the syrinx and who were followed up for 6 months. Clinical scales, urodynamic, neurophysiological, magnetic resonance (MR) and studies of ano-rectal manometry were performed to assess possible improvements.

RESULTS

In all the cases, MR at the end of the study showed a clear reduction of the syrinx, and, at this time, signs of improvement in the urodynamic studies were found. Moreover, four patients improved in ano-rectal manometry. Four patients improved in neurophysiological studies, with signs of improvement in evoked potentials in three patients. In the American Spinal Injury Association (ASIA) assessment, only two patients improved in sensitivity, but clinical improvement in neurogenic bowel dysfunction was observed in four patients and three patients described improvement in bladder dysfunction. Spasms reduced in two of the five patients who had them previous to cell therapy, and spasticity was improved in the other two patients. Three patients had neuropathic pain before treatment, and it was reduced or disappeared completely during the study. Only two adverse events ocurred, without relation to the cell therapy.

CONCLUSIONS

Cell therapy can be considered as a new alternative to the treatment of post-traumatic syringomyelia, achieving reduction of syrinx and clinical improvements in individual patients.

Enhanced recovery care after colorectal surgery in elderly patients. Compliance and outcomes of a multicenter study from the Spanish working group on ERAS

PURPOSE

ERAS (enhanced recovery after surgery) programs have proven to reduce morbidity and hospital stay in colorectal surgery. However, the feasibility of these programs in elderly patients has been questioned. The aim of this study is to assess the implementation and outcomes of an ERAS program for colorectal cancer in elderly patients.

METHODS

This is a multicenter observational study of a cohort of elderly patients undergoing colorectal surgery within an ERAS program. A total of 188 consecutive patients over 70 years who underwent elective colorectal surgery within an ERAS program at three institutions during a 2-year period were included. The compliance with the ERAS protocol interventions was measure. Complications were evaluated according to Clavien-Dindo classification. Data on length of stay and readmission rates were analyzed.

RESULTS

Early intake and early mobilization were the most successfully carried out interventions. There was a global compliance rate of 56 % of patients for whom compliance was achieved with all measured interventions. The median hospital length of stay was 6 days. Almost 60 % of patients had no complications, 24 % had minor complications while 13 % had major complications; of them, 8 % patients were reoperated. The readmission rate was 6.4 %.

CONCLUSIONS

ERAS after colorectal surgery in elderly patients presents as safe and feasible based on good reported outcomes of compliance rates, complications, readmissions, and needs for reoperation.

First-in-Human Case Study: Pregnancy in Women With Crohn's Perianal Fistula Treated With Adipose-Derived Stem Cells: A Safety Study

The aim of this study was to determine whether treatment with adipose-derived stem cells (ASCs) had any influence on fertility, course of pregnancy, newborn weight, or physical condition of newborns. We performed a retrospective study of patients with a desire to become pregnant after having received intralesional injection of autologous ASCs for the treatment of perianal or rectovaginal fistula associated with Crohn's disease. We collected data on the resulting pregnancies, deliveries, and newborns of these patients. ASCs were expanded in vitro and characterized according to the international guidelines for cell surface markers (clusters of differentiation) and differentiated to adipocytes, chondrocytes, and osteocytes prior to implantation (except first implant in 2002). We analyzed five young women with Crohn's disease treated with ASCs: one for rectovaginal and perianal fistula, two for rectovaginal fistula only, and two for perianal fistula only. All patients received 2 doses of 20 million and 40 million cells at an interval of 3-4 months. Another patient received 2 doses of 6.6 million and 20 million ASCs with 9 months between each dose. Fertility and pregnancy outcomes were not affected by cell therapy treatment. No signs of treatment-related malformations were observed in the neonates by their respective pediatricians. In the patients studied, cell therapy with ASCs did not affect the course of pregnancy or newborn development.

SIGNIFICANCE

Local treatment with mesenchymal stem cells derived from adipose tissue seems not to affect the ability to conceive, the course of pregnancy, pregnancy outcomes, or newborns' health in female patients. This is the first publication about pregnancy outcome in women with perianal fistula and Crohn's disease treated with stem cell therapy, and could be of interest for doctors working in cell therapy. This is a very important question for patients, and there was no answer for them until now.

Recurrent anal fistulae: Limited surgery supported by stem cells

AIM: To study the results of stem-cell therapy under a Compassionate-use Program for patients with recurrent anal fistulae.

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 very complex anal fistulae. Candidates had previously undergone multiple surgical interventions that had failed to resolve the fistulae, and presented symptomatic recurrence. The intervention consisted of limited surgery (with closure of the internal opening), followed by local implant of stem cells in the fistula-tract wall. Autologous expanded adipose-derived stem cells were the main cell type selected for implant. The first evaluation was performed on the 8^th postoperative week; outcome was classified as response or partial response. Evaluation one year after the intervention confirmed if complete healing of the fistula was achieved.

RESULTS: Ten patients (8 male) with highly recurrent and complex fistulae were treated (mean age: 49 years, range: 28-76 years). Seven cases were non-Crohn’s fistulae, and three were Crohn’s-associated fistulae. Previous surgical attempts ranged from 3 to 12. Two patients presented with preoperative incontinence (Wexner scores of 12 and 13 points). After the intervention, six patients showed clinical response on the 8^th postoperative week, with a complete cessation of suppuration from the fistula. Three patients presented a partial response, with an evident decrease in suppuration. A year later, six patients (60%) remained healed, with complete reepithelization of the external opening. Postoperative Wexner Scores were 0 in six cases. The two patients with previous incontinence improved their scores from 12 to 8 points and from 13 to 5 points. No adverse reactions or complications related to stem-cell therapy were reported during the study period.

CONCLUSION: Stem cells are safe and useful for treating anal fistulae. Healing can be achieved in severe cases, sparing fecal incontinence risk, and improving previous scoring.

Oncogenic transformation induced by cell-free nucleic acids circulating in plasma (genometastasis) remains after the surgical resection of the primary tumor: a pilot study

BACKGROUND

The oncogenic transformation by cell-free nucleic acids circulating in plasma has been named as genometastasis. The feasibility of this phenomenon has been demonstrated and now it is necessary to value the impact of this phenomenon and to determine what conditions could promote or inhibit it. The goal of this study was to examine the transforming ability of plasma from colorectal cancer patients in a long-term follow-up after the surgical excision of the primary tumor, and to try correlate it with the clinical picture of patients.

MATERIALS AND METHODS

Blood samples were taken from eight patients with K-ras-mutated colorectal tumors, who were under surgical primary tumor resection at least 2 years before. Plasma was isolated by two centrifugations and added to cultures of NIH-3T3 cells and human adipose-derived stem cells (hASCs). In two cases, plasma was separated from cells by a membrane with 0.4-μm pores. The presence of mutated and non-mutated human K-ras sequences was tested by real-time PCR in cultured cells. After 30 days, cells were subcutaneously injected into athymic nude mice in order to test their ability to generate tumors.

RESULTS

In four of the eight patients analyzed after surgery, tumor DNA was detected in plasma. Plasmas from three of them were able to oncogenically transform NIH-3T3 cells in culture and, when those cells were injected in mice, carcinomas were generated. After a 2-year follow-up, metastases were found in two of the three patients whose plasmas were able to transform cells, and in two of the four in whom plasma tumor DNA was not detected. Thus, after a mean follow-up of 29.5 months, only four of 13 patients (30.8%) were alive and disease-free.

CONCLUSION

Primary tumor resection does not assure a complete clean of blood of circulating oncogenes, in spite of a disease-free clinical picture. Moreover, in some cases plasma kept their oncogenic capabilities. The value of these findings as prognosis factor remains unclear and needs further investigations.

Long-term follow-up of patients undergoing adipose-derived adult stem cell administration to treat complex perianal fistulas

PURPOSE

In patients with perianal fistulas, administration of adult stem cells (ASCs) derived from liposuction samples has proved a promising technique in a preceding phase II trial. We aimed to extend follow-up of these patients with this retrospective study.

METHOD

Patients who had received at least one dose of treatment (ASCs plus fibrin glue or fibrin glue alone) were included. Adverse events notified since the end of the phase II study were recorded. Clinical and magnetic resonance imaging (MRI) criteria were used to determine whether recurrence of the healed fistula had occurred.

RESULTS

Data were available for 21 out of 24 patients treated with ASCs plus fibrin glue and 13 out of 25 patients treated with fibrin glue in the phase II study. Follow-up lasted a mean of 38.0 and 42.6 months, respectively. Two adverse events unrelated to the original treatment were reported, one in each group. There were no reports of anal incontinence associated with the procedure. Of the 12 patients treated with ASCs plus fibrin glue who were included in the retrospective follow-up in the complete closure group, only 7 remained free of recurrence. MRI was done in 31 patients. No relationship was detected between MRI results and the clinical fistula status, independent of the treatment received.

CONCLUSIONS

Long-term follow-up reaffirmed the very good safety profile of the treatment. Nevertheless, a low proportion of the stem cell-treated patients with closure after the procedure remained free of recurrence after more than 3 years of follow-up.