Tailored therapy for different presentations of chronic pain after stapled hemorrhoidopexy

Isolation and Characterization of Stem Cells from the Anal Canal Transition Zone in Pigs

BACKGROUND

Utilization of autologous stem cells has been proposed for the treatment of anal incontinence despite a lack of understanding of their mechanism of action and of the physiological healing process of anal sphincters after injury.

AIMS

We aim to develop a technique allowing isolation and further study of local mesenchymal stem cells, directly from anal canal transition zone in pig.

METHODS

Anal canal was resected "en bloc" from two young pigs and further microdissected. The anal canal transition zone was washed and digested with 0.1% type I collagenase for 45 min at 37 °C. The isolated cells were plated on dishes in mesenchymal stem cell medium and trypsinized when confluent. Cells were further used for flow cytometry analysis and differentiation assays.

RESULTS

The anal canal transition zone localization was confirmed with H&E staining. Following culture, cells exhibited a typical "fibroblast-like" morphology typical of stem cells. Isolated cells were positive for CD90 and CD44 but negative for CD14, CD34, CD45, CD105, CD106, and SLA-DR. Following incubation with specific differentiation medium, isolated cells differentiated into adipocytes, osteoblasts, and chondrocytes, confirming in vitro multipotency.

CONCLUSIONS

Herein, we report for the first time the presence of mesenchymal stem cells in the anal canal transition zone in pigs and the feasibility of their isolation. This preliminary study opens the path to the isolation of human anal canal transition zone mesenchymal stem cells that might be used to study sphincters healing and to treat anal incontinence.

Belgian consensus guideline on the management of hemorrhoidal disease

Introduction

Hemorrhoidal disease is a common problem that arises when hemorrhoidal structures become engorged and/or prolapse through the anal canal. Both conservative and invasive treatment options are diverse and guidance to their implementation is lacking.

Methods

A Delphi consensus process was used to review current literature and draft relevant statements. These were reconciliated until sufficient agreement was reached. The grade of evidence was determined. These guidelines were based on the published literature up to June 2020.

Results

Hemorrhoids are normal structures within the anorectal region. When they become engorged or slide down the anal canal, symptoms can arise. Every treatment for symptomatic hemorrhoids should be tailored to patient profile and expectations. For low-grade hemorrhoids, conservative treatment should consist of fiber supplements and can include a short course of venotropics. Instrumental treatment can be added case by case : infrared coagulation or rubber band ligation when prolapse is more prominent. For prolapsing hemorrhoids, surgery can be indicated for refractory cases. Conventional hemorrhoidectomy is the most efficacious intervention for all grades of hemorrhoids and is the only choice for non-reducible prolapsing hemorrhoids.

Conclusions

The current guidelines for the management of hemorrhoidal disease include recommendations for the clinical evaluation of hemorrhoidal disorders, and their conservative, instrumental and surgical management.

HYR-PB21-LA, a potential extended-release bupivacaine formulation, produces long-lasting local anesthesia in rats and guinea pigs

BACKGROUND

Effective postoperative pain management plays a key role in enhancing recovery of patients after surgery. Bupivacaine hydrochloride is one of the most commonly local anesthetics used for the postoperative pain control. However, the relatively short anesthesia duration of bupivacaine preparations limited their clinical application.

METHODS

Both guinea pig pin-prick study and rat tail-flick test were performed to evaluate the local anesthesia efficacy of HYR-PB21-LA, a new microparticle suspension injection of bupivacaine pamoate.

RESULTS

In the pin-prick test, the complete cutaneous trunci muscle reflex inhibitions were observed at 30 min in all treatment groups containing bupivacaine. In comparison with 6.7 mg/mL HYR-PB21-LA, both 10 and 20 mg/mL HYR-PB21-LA groups had significantly higher area under effect time curve (AUEC) values (p<0.001 and p<0.0001) and slower offset time (p<0.0001). Significantly higher AUEC (p<0.0001) and slower offset time (p<0.0001) were also found in 10 mg/mL HYR-PB21-LA treatment group compared with bupivacaine liposome injectable suspension (liposomal bupivacaine). In the rat tail-flick test, significantly increased local anesthesia effect was lasted for 5 hours after 2.5 mg/mL HYR-PB21-LA administration, which was fivefold longer than bupivacaine hydrochloride. The longer lasted efficacy of significantly increased local anesthesia was also observed in 5 mg/mLHYR-PB21-LA than those in liposomal bupivacaine (8 hour vs 1 hour).

CONCLUSIONS

The results demonstrated that the HYR-PB21-LA produced longer local anesthesia effect than current clinical preparations of bupivacaine in two animal models. These findings raise the potential clinical value of HYR-PB21-LA as a long-lasting local anesthesia for controlling postsurgical pain in humans.