Bovine pericardium patch wrapping intestinal anastomosis improves healing process and prevents leakage in a pig model.

Failure of intestinal anastomosis is a major complication following abdominal surgery. Biological materials have been introduced as reinforcement of abdominal wall hernia in contaminated setting. An innovative application of biological patch is its use as reinforcement of gastrointestinal anastomosis. The aim of study was to verify whether the bovine pericardium patch improves the healing of anastomosis, when in vivo wrapping the suture line of pig intestinal anastomosis, avoiding leakage in the event of deliberately incomplete suture. Forty-three pigs were randomly divided: Group 1 (control, n = 14): hand-sewn ileo-ileal and colo-colic anastomosis; Group 2 (n = 14): standard anastomosis wrapped by pericardium bovine patch; Group 3 (n = 1) and 4 (n = 14): one suture was deliberately incomplete and also wrapped by patch in the last one. Intraoperative evaluation, histological, biochemical, tensiometric and electrophysiological studies of intestinal specimens were performed at 48 h, 7 and 90 days after. In groups 2 and 4, no leak, stenosis, abscess, peritonitis, mesh displacement or shrinkage were found and adhesion rate decreased compared to control. Biochemical studies showed mitochondrial function improvement in colic wrapped anastomosis. Tensiometric evaluations suggested that the patch preserves the colic contractility similar to the controls. Electrophysiological results demonstrated that the patch also improves the mucosal function restoring almost normal transport properties. Use of pericardium bovine patch as reinforcement of intestinal anastomosis is safe and effective, significantly improving the healing process. Data of prevention of acute peritonitis and leakage in cases of iatrogenic perforation of anastomoses, covered with patch, is unpublished

Targeting the bicarbonate transporter SLC4A4 overcomes immunosuppression and immunotherapy resistance in pancreatic cancer

Solid tumors are generally characterized by an acidic tumor microenvironment (TME) that favors cancer progression, therapy resistance, and immune evasion. By single-cell RNA-sequencing analysis in PDAC patients, we reveal hereby Solute Carrier Family 4 Member 4 (SLC4A4) as the most abundant bicarbonate transporter, predominantly expressed by epithelial ductal cells. Functionally, SLC4A4 inhibition in PDAC cancer cells mitigates the acidosis of the TME due to bicarbonate accumulation in the extracellular space and decrease in lactate production by cancer cells as the result of reduced glycolysis. In PDAC-bearing mice, genetic or pharmacological SLC4A4 targeting improves T cell-mediated immune response and breaches macrophage-mediated immunosuppression, thus inhibiting tumor growth and metastases. In addition, Slc4a4 targeting in combination with immune-checkpoint blockade is able to overcome immunotherapy resistance and prolong survival. Overall, our data propose SLC4A4 as a therapeutic target to unleash an anti-tumor immune response in PDAC

Intraoperative results.

<p>h: hours; pod: post-operative day; *colo-colic anastomosis; **both anastomosis.</p

(A–D) Mitochondrial respiration.

<p>Mitochondrial respiratory activities, from endogenous substrates (A), succinate (B) and ascorbate (C), and mitochondrial respiratory control ratios from endogenous respiration (D) in ileo-ileal (gray bars) and colo-colic (white bars) anastomosis. In each coupled bars values from Group 1 (left) and Group 2 (right) are compared.</p

(A–C) Intraoperative image and histological findings of intestinal anastomosis wrapped by pericardium bovine patch.

<p>Ileo-ileal anastomosis wrapped by a 50×20 mm one layer pericardium bovine patch (A); at day 7 (B) the patch is enveloped by an heavy lympho-isthyocitic infiltrate without essudation on the serosal surface (Group 2) and after 48 h (C) the necrotic tissue is well contained into the intestinal wall by the patch (Group 4), with minimal leukocyte infiltration of the serosal surface (Haematoxylin-Eosin 200X original magnification).</p

(A–D) Analysis of the others mitochondrial activities and reactive oxygen species.

<p>Mitochondrial activities of citrate synthase (A), NADH-ubiquinone oxidoreductase (B), cytochrome c oxidase (C) and hydrogen peroxide production (D) in ileo-ileal (gray bars) and colo-colic (white bars) anastomosis. In each coupled bars values from Group 1 (left) and Group 2 (right) are compared.</p

Mean Adhesion Score.

<p>h: hours; pod: post-operative day. Mean score ± SEM. *Adhesion rate I: 0 =  no adhesion; 1 =  adhesions with one structure; 2 =  adhesions with two structures; 3 =  adhesions with three or more structures. **Adhesion rate II: 0 =  no adhesions; 1 =  light adhesions; 2 =  fixed adhesions; 3 =  solid adhesions, only removable with damage.</p

(A–D) Electrophysiological measurements.

<p>Short circuit current (I_SC) and tissue resistance (R_T) in ileal and colic specimens. Bars represent mean ± SEM in C (before surgery, N = 15), A-ES (after surgery without patch, early stage, N = 15), P-ES (after surgery with patch, early stage, N = 15), A-LS (after surgery without patch, late stage, N = 10), P-LS (after surgery with patch, late stage, N = 10) in ileal and colic specimens, respectively. Significance was determined by Student's t test for unpaired data of follow-up stage <i>vs</i> control (*p≤0.05; **p≤ 0.002; ***p≤0.0001) and for anastomoses with patch <i>vs</i> anastomoses without patch control (#: p≤0.05).</p

Microscopic Findings and Mean Histological Score.

<p>h: hours; pod: post-operative day; mean score ± SEM. *Score 0-4: 0 =  absent; 1 =  minimal; 2 =  moderate; 3 =  distinctive; 4 =  severe.</p

Bovine Pericardium Patch Wrapping Intestinal Anastomosis Improves Healing Process and Prevents Leakage in a Pig Model

Failure of intestinal anastomosis is a major complication following abdominal surgery. Biological materials have been introduced as reinforcement of abdominal wall hernia in contaminated setting. An innovative application of biological patch is its use as reinforcement of gastrointestinal anastomosis. The aim of study was to verify whether the bovine pericardium patch improves the healing of anastomosis, when in vivo wrapping the suture line of pig intestinal anastomosis, avoiding leakage in the event of deliberately incomplete suture. Forty-three pigs were randomly divided: Group 1 (control, n = 14): hand-sewn ileo-ileal and colo-colic anastomosis; Group 2 (n = 14): standard anastomosis wrapped by pericardium bovine patch; Group 3 (n = 1) and 4 (n = 14): one suture was deliberately incomplete and also wrapped by patch in the last one. Intraoperative evaluation, histological, biochemical, tensiometric and electrophysiological studies of intestinal specimens were performed at 48 h, 7 and 90 days after. In groups 2 and 4, no leak, stenosis, abscess, peritonitis, mesh displacement or shrinkage were found and adhesion rate decreased compared to control. Biochemical studies showed mitochondrial function improvement in colic wrapped anastomosis. Tensiometric evaluations suggested that the patch preserves the colic contractility similar to the controls. Electrophysiological results demonstrated that the patch also improves the mucosal function restoring almost normal transport properties. Use of pericardium bovine patch as reinforcement of intestinal anastomosis is safe and effective, significantly improving the healing process. Data of prevention of acute peritonitis and leakage in cases of iatrogenic perforation of anastomoses, covered with patch, is unpublished