Challenges in creating dissectible anatomical 3D prints for surgical teaching.

Three-dimensional (3D) printing, or additive manufacturing, is now a widely used tool in pre-operative planning, surgical teaching and simulator training. However, 3D printing technology that produces models with accurate haptic feedback, biomechanics and visuals for the training surgeon is not currently available. Challenges and opportunities in creating such surgical models will be discussed in this review paper. Surgery requires proper tissue handling as well as knowledge of relevant anatomy. To prepare doctors properly, training models need to take into account the biomechanical properties of the anatomical structures that will be manipulated in any given operation. This review summarises and evaluates the current biomechanical literature as it relates to human tissues and correlates the impact of this knowledge on developing high fidelity 3D printed surgical training models. We conclude that, currently, a printer technology has not yet been developed which can replicate many of the critical qualities of human tissue. Advances in 3D printing technology will be required to allow the printing of multi-material products to achieve the mechanical properties required.

Fournier's gangrene - delayed pedicle flap based upon the anterior abdominal wall.

INTRODUCTION: Fournier's gangrene is a poly-microbial necrotizing fasciitis that involves the perineum and/or external genitalia. Urgent surgical debridement is well recognized as essential acute treatment yet unique challenges arise for plastic surgical reconstruction to obtain a complete functional recovery. This case describes a successful delayed pedicle flap repair based upon the anterior abdominal wall. CASE DESCRIPTION: A 24 year old man was admitted to ICU ten days after elective circumcision with Fournier's gangrene. He underwent a number of surgical debridements, and was referred for plastic surgical management. He had penile reconstruction using a random pattern abdominal flap, which was performed as a three stage procedure including flap vascular delay technique. DISCUSSION: Perineal and penile skin loss can be significant and is difficult to repair. Various techniques have been used to reconstruct lost tissue: skin grafts, transposition of the testes and spermatic cords to the thigh, flaps, and other types of pediculated myocutaneous flaps. Muscle flap reconstruction provides an environment that allows for complete regeneration of the urethral epithelium but is bulky and unsightly. Skin grafts contract and may produce painful and dysfunctional reconstructions. This novel technique produces a functional, and aesthetic reconstruction. CONCLUSION: Penile skin recovery following Fournier's gangrene recovery is problematic. This case demonstrates the functionality of a delayed flap repair using the anterior abdominal wall.

Fournier?s gangrene - delayed pedicle flap based upon the anterior abdominal wall

Introduction Fournier’s gangrene is a poly-microbial necrotizing fasciitis that involves the perineum and/or external genitalia. Urgent surgical debridement is well recognized as essential acute treatment yet unique challenges arise for plastic surgical reconstruction to obtain a complete functional recovery. This case describes a successful delayed pedicle flap repair based upon the anterior abdominal wall. Case description A 24 year old man was admitted to ICU ten days after elective circumcision with Fournier’s gangrene. He underwent a number of surgical debridements, and was referred for plastic surgical management. He had penile reconstruction using a random pattern abdominal flap, which was performed as a three stage procedure including flap vascular delay technique. Discussion Perineal and penile skin loss can be significant and is difficult to repair. Various techniques have been used to reconstruct lost tissue: skin grafts, transposition of the testes and spermatic cords to the thigh, flaps, and other types of pediculated myocutaneous flaps. Muscle flap reconstruction provides an environment that allows for complete regeneration of the urethral epithelium but is bulky and unsightly. Skin grafts contract and may produce painful and dysfunctional reconstructions. This novel technique produces a functional, and aesthetic reconstruction. Conclusion Penile skin recovery following Fournier’s gangrene recovery is problematic. This case demonstrates the functionality of a delayed flap repair using the anterior abdominal wall. .

Trapeziectomy with ligament reconstruction and tendon interposition: a minimum 10-year follow-up.

PURPOSE: To investigate the long-term (> 10 yrs) outcomes of trapeziectomy with ligament reconstruction and tendon interposition (LRTI). METHODS: We reviewed 15 cases of trapeziectomy with LRTI performed for the treatment trapeziometacarpal osteoarthritis. Mean follow up was 13.5 yrs (range, 10.5-17.5 yrs). We assessed a number of subjective and objective outcomes. A good outcome was a participant who did not require revision surgery, was satisfied with the outcome of their surgery and did not experience rest pain. RESULTS: No patients had revision surgery and only two patients were unsatisfied or very unsatisfied with the outcome of their surgery. Pain with activity was the strongest predictor of participant satisfaction. DISCUSSION: Approximately half the participants in this study experienced good long-term outcomes. Some participants were experiencing long-term symptoms, particularly pain, despite reporting that they are satisfied with the outcome of their surgery. Alternative techniques should be investigated that provide superior long-term outcomes.

Late complications of clinical clostridium histolyticum collagenase use in Dupuytren's disease.

INTRODUCTION: While Dupuytren's disease can cause disabling contractures requiring open surgery, a less-invasive option using Clostridium Histolyticum collagenase (CHC) via percutaneous injection was recently reported. A recent prospective, randomized trial demonstrated few complications during 90 days follow-up, however did not assess any longer term follow-up for these patients. Long-term outcomes in this setting have not been adequately reported, and the current manuscript aims to identify late complications from the clinical use of percutaneous CHC. METHODS: The current manuscript reports an extended 12-month follow-up for a cohort of twelve of patients enrolled in the original prospective, randomized trial, treated at a single institution. An analysis of complications requiring surgical intervention was undertaken. RESULTS: Two of twelve patients reported debilitating pain and triggering requiring surgical intervention. Extensive deep-tissue scarring and adhesions were identified, providing the first visual and qualitative analysis of the pathologic effects of CHC. CONCLUSION: Late complications from CHC use can and have occurred, outside the follow-up period of the initial phase III trials. Longer term follow-up of such patients is thus essential, and further investigation and characterization of the late effects of CHC use is warranted.

Free deep circumflex iliac artery vascularised bone flap for reconstruction of the distal radius: planning with CT angiography.

Distal radius fractures in the younger population are often comminuted and intra-articular, which can increase the complexity of their management. In addition, these patients tend to place high demands on their wrists, and the prevention of functional arthritis necessitates excellent anatomical reduction. Complicated cases such as these are often limited in their management options. We present a complex case of distal radius fracture and bone loss in which initial therapy with nonvascularized bone graft failed, and osteomyelitis was a further complicating factor. With the aid of preoperative planning with computed tomographic angiography (CTA), a deep circumflex iliac artery (DCIA) bone flap was able to be assessed as a reconstructive option. The use of preoperative CTA, the first description of such imaging in this role, was able to delineate the bone to be harvested, confirm its vascular supply, and plan flap harvest. The use of a vascularized bone flap in this setting was thus undertaken and was able to provide an autologous anatomical support for the wrist while reducing the risk of recurrent infection and still preserving internal fixation. This unique application of the free DCIA bone flap was potentiated by CTA, achieving complete healing and good functional outcomes.

A cDNA clone for beta-caryophyllene synthase from Artemisia annua.

An homology-based cloning strategy yielded a full-length cDNA from Artemisia annua that encoded a protein of 60.3 kDa which resembled a sesquiterpene synthase in sequence. Heterologous expression of the gene in Escherichia coli provided a soluble recombinant enzyme capable of catalyzing the divalent metal ion-dependent conversion of farnesyl diphosphate to beta-caryophyllene, a sesquiterpene olefin found in the essential oil of A. annua. In reaction parameters and kinetic properties, beta-caryophyllene synthase resembles other sesquiterpene synthases of angiosperms. The beta-caryophyllene synthase gene is expressed in most plant tissues during early development, and is induced in mature tissue in response to fungal elicitor thus suggesting a role for beta-caryophyllene in plant defense.