Breaking the technical barrier of microvascular anastomosis with high-speed videography: A prospective cohort study

Development and external validation of a prediction model for digit replantation failure after traumatic amputations based on a prospective multicenter cohort

BACKGROUND

Failure of digit replantation after traumatic amputation is difficult to predict. The authors aimed to develop a prognostic model to better identify factors that better predict replantation failure following traumatic digit amputation.

MATERIALS AND METHODS

In this multicenter prospective cohort, the authors identified patients who had received digit replantation between 1 January 2015 and 1 January 2019. Univariable and multivariable analyses were performed successively to identify independently predictive factors for failure of replanted digit. To reduce overfitting, the Bayesian information criterion was used to reduce variables in the original model. Nomograms were created with the reduced model after model selection. This model was then internally validated with bootstrap resampling and further externally validated in validation cohort.

RESULTS

Digit replantation was failed in 101 of 1062 (9.5%) digits and 146 of 1156 digits (12.6%) in the training and validation cohorts, respectively. The authors found that six independent prognostic variables were associated with digit replantation failure: age, mechanism of injury, ischemia duration, smoking status, amputation pattern (complete or incomplete), and surgeon's experience. The prediction model achieved good discrimination, with concordance indexes of 0.81 (95% CI: 0.76-0.85) and 0.70 (95% CI: 0.65-0.74) in predicting digit failure in the training and validation cohorts, respectively. Calibration curves were well-fitted for both training and validation cohorts.

CONCLUSIONS

The proposed prediction model effectively predicted the failure rate of digit replantation for individual digits of all patients. It could assist in selecting the most suitable surgical plan for the patient.

Nanothermometry-Enabled Intelligent Laser Tissue Soldering

While often life-saving, surgical resectioning of diseased tissues puts patients at risk for post-operative complications. Sutures and staples are well-accepted and routinely used to reconnect tissues, however, their mechanical mismatch with biological soft tissue and invasiveness contribute to wound healing complications, infections, and post-operative fluid leakage. In principle, laser tissue soldering offers an attractive, minimally-invasive alternative for seamless soft tissue fusion. However, despite encouraging experimental observations, including accelerated healing and lowered infection risk, critical issues related to temperature monitoring and control during soldering and associated complications have prevented their clinical exploitation to date. Here, intelligent laser tissue soldering (iSoldering) with integrated nanothermometry is introduced as a promising yet unexplored approach to overcome the critical shortcomings of laser tissue soldering. It demonstrates that adding thermoplasmonic and nanothermometry nanoparticles to proteinaceous solders enables heat confinement and non-invasive temperature monitoring and control, offering a route to high-performance, leak-tight tissue sealing even at deep tissue sites. The resulting tissue seals exhibit excellent mechanical properties and resistance to chemically-aggressive digestive fluids, including gastrointestinal juice. The iSolder can be readily cut and shaped by surgeons to optimally fit the tissue defect and can even be applied using infrared light from a medically approved light source, hence fulfilling key prerequisites for application in the operating theatre. Overall, iSoldering enables reproducible and well-controlled high-performance tissue sealing, offering new prospects for its clinical exploitation in diverse fields ranging from cardiovascular to visceral and plastic surgery.

A Novel Utility of Bilobed Flap for Amputation Stump Coverage

Preparing a good amputation stump with a well-padded, stable, sensate, and painless soft tissue coverage is of utmost importance to achieve early ambulation and return the patient to the daily activity level. When the primary closure is impossible or fails to achieve a good closure, secondary closure must be considered. To date, no literature reported the use of bilobed flaps for stump defect closure. We aimed to utilize this technically easy procedure for better management of defect closure on amputated limb stumps that often cause complex clinical problems. This is a retrospective observational study in limb amputation patients with various etiologies: crush injury, chronic limb necrosis, and amniotic band syndrome. All patients had stump defect closure with bilobed flap and were observed with a minimum of 6-months follow-up to evaluate the wound healing, the use of prosthesis, and the complications. A bilobed flap was performed in 11 amputation cases as the final closure (64% trans-femoral, 18% trans-tibial, 9% trans-humeral, and 9% trans-radial). The mean follow-up time was 8.5 ± 2.21 months. Most of the patients healed uneventfully with the optimal use of prosthesis in a mean healing time of 29.64 ± 7.49 days. The bilobed flap potentially provides a good amputation stump coverage that is ideal for prosthesis fitting. This simple procedure can be done without the necessity of special microsurgery settings. Thus, when the neighboring tissue is available and mobile enough to be transposed to the stump defect, a bilobed flap can be considered.

New Robotic System with Wristed Microinstruments Allows Precise Reconstructive Microsurgery: Preclinical Study

BACKGROUND

Microsurgery allows complex reconstruction of tissue defects after oncological resections or severe trauma. Performing these procedures may be limited by human tremor, precision, and manual dexterity. A new robot designed specifically for microsurgery with wristed microinstruments and motion scaling may reduce human tremor and thus enhance precision. This randomized controlled preclinical trial investigated whether this new robotic system can successfully perform microsurgical needle driving, suturing, and anastomosis.

METHODS

Expert microsurgeons and novices completed six needle passage exercises and performed six anastomoses by hand and six with the new robot. Experienced microsurgeons blindly assessed the quality of the procedures. Precision in microneedle driving and stitch placement was assessed by calculating suturing distances and angulation. Performance of microsurgical anastomoses was assessed by time, learning curves, and the Anastomosis Lapse Index score for objective performance assessment.

RESULTS

Refined precision in suturing was achieved with the robot when compared with the manual technique regarding suture distances (p = 0.02) and angulation (p < 0.01). The time required to perform microsurgical anastomoses was longer with the robot, however, both expert and novice microsurgeons reduced times with practice. The objective evaluation of the anastomoses performed by novices showed better results with the robot.

CONCLUSIONS

This study demonstrated the feasibility of performing precise microsutures and anastomoses using a new robotic system. Compared to standard manual techniques, robotic procedures were longer in time, but showed greater precision.