Zebrafish fin regeneration involves transient serotonin synthesis.

The zebrafish is a vertebrate organism capable of regenerating many of its organs. Notably, it can undergo epimorphic regeneration of its fins after amputation. This process occurs through the formation of a wound epithelium and the dedifferentiation of mesenchymal and bone-forming cells, which form a proliferative blastema. Here, we report that the entry into the regenerative process involves the local synthesis of serotonin (5-hydroxytryptamine, 5-HT) in the injury-associated tissue. One day after wounding, intracellular accumulation of serotonin was induced in the stump below the amputation plane. During blastema formation, serotonin was detected in the mesenchyme at the vicinity of the amputation plane and in the apical wound epithelium. During the advanced outgrowth phase, this monoamine was no longer present in the blastema, suggesting a temporal involvement of serotonin in the postinjury area. We show the expression of two serotonin synthesizing enzymes, tryptophan hydroxylase 1a and 1b in the blastema, suggesting the local production of this monoamine. Neither depletion of serotonin by chemical inhibition of tryptophan hydroxylase, nor ectopic administration of this monoamine affected fin regeneration, indicating it does not play a role during this process. Finally, we found that the presence of serotonin during regeneration depends on fibroblast growth factor and retinoic acid signaling. Overall, our study demonstrates that the initiation of fin regeneration is associated with a transient synthesis of serotonin in the regrowing tissue.

[Critical ischemia of hip stump. Incidence, clinical significance and diagnosis]. / Kriticheskaia ishemiia kul'ti bedra: chastota, klinicheskoe znachenie i diagnostika.

AIM: To study the incidence of hip stump ischemia, risk factors for 5-year survival after amputation, clinical features and diagnosis of this complication. MATERIAL AND METHODS: 1287 patients with peripheral artery disease followed by hip amputation were examined within 1997-2015. 50 of them had stump ischemia. RESULTS: It was found that hip stump ischemia occurs in 5.2% of cases and significantly aggravates 5-year survival. Transcutaneous oxygen tension less than 20 mm Hg is reliable hemodynamic criterion of ischemia.

[Ischaemia of a femoral stump in short- and long-term periods after limb amputation]. / Ishemiia kul'ti bedra v rannem i pozdnem periodakh posle amputatsii.

The authors retrospectively analysed medical case histories of 287 patients subjected to femoral amputations over the period from January 1, 1998 to December 31, 2013. The studied parameters were as follows: the frequency of and risk factors for femoral stump ischaemia, as well as the effect on patients' survival after femoral amputation. Amongst 156 patients having endured transfemoral truncation of the limb performed as the first amputation, early femoral stump ischaemia (EFSI) within 3 postoperative months was found to have occurred in 43 (27.6%) patients, whereas amongst 127 patients first subjected to amputation of the crus and then to femoral truncation it occurred in 15 (13.2%) cases; p<0.05. The incidence rate of late femoral stump ischaemia (LFSI) was virtually similar in both groups, amounting to 5.8% (9 of 156) and 5.5% (7 of 127), respectively; p>0.05. The survival rate for patients without stump ischaemia at 12 months after amputation amounted to 79.4%, for those with EFSI to 50.0% (p=0.00928), and for those with LFSI to 71.4% (p=0.22576), whereas by the end of a 5-year follow up period these values appeared to equal 49.2%, 32.1% (p=0.13225) and 7.1% (p=0.01385), respectively. The obtained findings demonstrated that the risk factors for EFSI were as follows: the presence of a femoral stump on the contralateral side, grade III ischaemia, and proximal localization of the lesion of the arterial bed (odds ratio 3.3, 2.7 and 3.8, respectively); a risk factor for LFSI was the presence of a femoral stump on the contralateral side (odds ratio 6.0).

[Five-year survival and outcomes of chronic hip stump ischemia treatment]. / Piatiletniaia vyzhivaemost' i rezul'taty lecheniia khronicheskoi ishemii kul'ti bedra.

AIM: To investigate five-year survival, short- and long-term outcomes of hip stump ischemia treatment. MATERIAL AND METHODS: There were 383 patients with hip stump in 1997-2013. Critical hip stump ischemia in 3 months after amputation occurred in 45 patients. RESULTS: Two-fold decrease of 5-year survival was found. Five-year survival was higher 3 times in patients after arterial reconstruction compared with those without revascularization. The same tendency was confirmed in analysis of groups standardized by gender, age and type of arterial disease.

Microcirculatory Assessment of Arterial Below-Knee Stumps: Near-Infrared Spectroscopy Versus Transcutaneous Oxygen Tension-A Preliminary Study in Prosthesis Users.

OBJECTIVE: To examine metrologic properties of near-infrared spectroscopy (NIRS) versus transcutaneous oxygen tension (TcPO2) for microcirculatory assessment of vascular transtibial stumps at the stabilized period of prosthesis fitting, as a preliminary step before exploring its ability to predict stump healing, considering the previously identified limits of TcPO2 (borderline area between 15 and 35mmHg). DESIGN: Prospective single-center observational study. SETTING: University-based rehabilitation center. PARTICIPANTS: Individuals with unilateral transtibial amputation for peripheral artery disease, at the definitive stage of prosthesis fitting, able to perform a 2-minute walk test (N=30). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Test-retest, with the stump being evaluated in supine and inclined positions, first by NIRS (tissue saturation index [TSI], oxyhemoglobin, deoxyhemoglobin, and total hemoglobin) and second by TcPO2. Subjects carried out a 2-minute walk test and visual analog scales (wound healing and pain). RESULTS: Feasibility and tolerance of NIRS were satisfactory. The reliability of NIRS and TcPO2 values was good (intraclass correlation coefficient >0.7; P<.05). No significant relation was found between NIRS and TcPO2. No responsiveness (inclined vs supine) was reported (P>.05). A significant relation between TSI and the 2-minute walk test (r>.49, P<.05) was found. CONCLUSIONS: NIRS is painless, complication-free, and feasible, with good reliability. NIRS evaluates others domain than TcPO2 that are more linked to metabolic adaptation. Its capacity to predict stump healing and tolerance to early prosthesis fitting is therefore interesting to estimate in future studies.

Amputation Stump Revision Using a Free Sural Neurocutaneous Perforator Flap.

BACKGROUND: The development of microsurgery and the concept of the surgical flap have enabled orthopedic surgeons to deal with various soft tissue defects and compositions during limb salvage procedures. However, severely damaged bony structures with accompanying soft tissue deficiencies often result in amputation. When performing amputations, surgeons must preserve the stump length to maximize functional ambulation, even during the posttraumatic phase and chronic period when a fillet flap is not an option. PATIENTS AND METHODS: Eleven patients with previous below-knee amputation were enrolled in our study from January 2006 to December 2011. Each patient underwent stump revision using a free sural neurocutaneous perforator flap. Preoperative and postoperative data were reviewed to evaluate the functional and aesthetic results. RESULTS: The 11 patients comprised 7 men and 4 women with an average age of 35.6 years (range, 26.0-49.0 years). The mean follow-up period was 15.3 months (range, 10.0 months-2.0 years). All free flap reconstructions of the amputation stump ultimately survived. All patients achieved both superficial and deep sensory recovery and are comfortable with their prostheses, and none have required further surgical intervention. CONCLUSIONS: The sural neurocutaneous perforator flap provided stable coverage and improved patients' quality of life by aiding in early rehabilitation and prosthetic fitting, function, and comfort.

Acroangiodermatitis in a lower leg amputee related to suction socket use.

Acroangiodermatitis is a rare condition with numerous causes typically presenting as purple macules on the lower extremities. Although benign, it can mimic the presentation of more serious underlying conditions such as Kaposi's sarcoma. We present a case of acroangiodermatitis in the stump of an amputee related to suction socket use in order to raise awareness of an unusual setting for this vascular proliferation.

[Transtibial amputation salvage with a cutaneous flap based on posterior tibial perforators]. / Sauvetage d'un moignon d'amputation transtibiale grâce à un lambeau cutané basé sur les perforantes de l'artère tibiale postérieure.

When performing an amputation of the lower limb, the preservation of the knee joint is important to obtain an optimal functional outcome. Many reconstruction procedures are available to cover the amputation defect in order to preserve a sufficient length of the stump, so a prosthesis could be put in place with the best functional results. Local musculocutaneous flaps or free flaps are conventionally described with their advantages and disadvantages. In this report, we describe our experience with a transtibial amputation and stump covering using a fasciocutaneous flap based on tibial posterior perforators. An extensive tibial bone exposure with only posterior skin was viable. It is an efficient and reliable solution for covering tibial stump without microvascular anastomosis.

Latissimus dorsi flap coverage of soft tissue defect following below-knee amputation: emphasis on flap design and recipient vessels.

High-energy trauma to the lower extremity often results in amputation of the limb. For maximal preservation of limb length during amputation, free tissue transfer is often necessary. In this study, we report our experience of stump coverage using latissimus dorsi musculocutaneous flaps with an emphasis on flap design and recipient vessels. Between January 2005 and September 2010, twelve patients with severe traumatic injuries to the lower leg underwent below-knee amputations with stump coverage using latissimus dorsi free flaps. The primary and secondary cases were approached differently regarding the flap design and recipient vessels. All flaps survived completely. There were 8 primary cases and 4 secondary cases. In the primary cases, the anterior tibial artery was used as the recipient vessel in 6 cases, and in 2 cases, the descending geniculate artery was used. In the secondary cases, the descending geniculate artery was used in all cases. There were two cases of ulceration on the grafted non-weight-bearing site, but after the usage of collagen-elastin artificial dermis, no ulcerations were seen. The latissimus dorsi musculocutaneous flap is the most feasible option for coverage of amputation stumps. In flap design, the width of the skin paddle must match the anteroposterior diameter of the defect at the stump. The latissimus dorsi muscle must sufficiently wrap the bony stump for padding. We recommend using the anterior tibial artery as a recipient vessel in primary cases, and the descending geniculate artery in secondary cases.

[Phlebothrombosis of the amputation femur stump: certain aspects of pathogenesis and prophylactics].

An experience with treatment of 455 patients who underwent transfemoral amputation was analyzed. In 54 patients (11.9%) phlebothrombosis of the femur stump developed in the early postoperative period. Certain little studied problems of pathogenesis of the complication in question are considered, possible variants of the clinical picture are described. Negative role of thrombosis of the femur stump veins is shown in the development of thromboembolism of the lung artery that was a direct cause of death of 20 patients. Prophylactics of stump phlebothrombosis allows getting less frequency of the development of this complication, decreased lethality, improvement of quality of life and duration of life of patients after transfemoral amputation.

[Limb amputations on the vascular patient]. / Majoramputationen beim Gefässpatienten.

For the rehabilitation after limb amputation is an as possible long stump necessary including good wound healing. For the vascular patient are the following amputation levels suitable: syme amputation, amputation of the lower leg, knee exarticulation, above knee amputation and very seldom hip exarticulation. Indication, surgical technics and following treatment are demonstrated.

Enhancing limb salvage by non-mobilized peripheral blood angiogenic cell precursors therapy in patients with critical limb ischemia.

BACKGROUND: Stem cell therapy has been proposed to enhance the salvage of critically ischemic limbs. OBJECTIVE: Assess the efficacy and safety of the implantation of non-mobilized peripheral blood angiogenic cell precursors (NMPB-ACPs) in patients with critical limb ischemia (CLI) who were poor candidates for standard revascularization treatment options. MATERIAL AND METHOD: Six patients with CLI due to the infrapopliteal artery occlusive disease were included in the present study. Intramuscular injections of NMPB-ACPs were administered in the ischemic limbs. The efficacy was evaluated by clinical outcomes, ankle brachial index, toe brachial index, and computerized tomographic angiography. RESULTS: There was no evidence of local or systemic complication related to the procedure. Five patients (83.3%) had clinically significant improvement of adequate circulation at the distal limb for the complete healing. Four of them had complete healing of ischemic ulcers and stumps of toe amputation. However one patient with adequate granulation tissue at the stump of the left first toe amputation subsequently suffered from severe foot infection originating from the other toes and eventually underwent below knee amputation. There was no improvement of circulation at the distal limb after the administration of NMPB-ACPs in one patient (16.7%) who eventually underwent major amputation. CONCLUSION: The preliminary result of NMPB-ACPs therapy may be safe and provide benefits in the improvement of circulation in patients with CLI. A larger controlled trial is required to ascertain these preliminary results.

Electrical stimulation shifts healing/scarring towards regeneration in a rat limb amputation model.

Different species respond differently to severe injury, such as limb loss. In species that regenerate, limb loss is met with complete restoration of the limbs' form and function, whereas in mammals the amputated limb's stump heals and scars. In in vitro studies, electrical stimulation (EStim) has been shown to promote cell migration, and osteo- and chondrogenesis. In in vivo studies, after limb amputation, EStim causes significant new bone, cartilage and vessel growth. Here, in a rat model, the stumps of amputated rat limbs were exposed to EStim, and we measured extracellular matrix (ECM) deposition, macrophage distribution, cell proliferation and gene expression changes at early (3 and 7 days) and later stages (28 days). We found that EStim caused differences in ECM deposition, with less condensed collagen fibrils, and modified macrophage response by changing M1 to M2 macrophage ratio. The number of proliferating cells was increased in EStim treated stumps 7 days after amputation, and transcriptome data strongly supported our histological findings, with activated gene pathways known to play key roles in embryonic development and regeneration. In conclusion, our findings support the hypothesis that EStim shifts injury response from healing/scarring towards regeneration. A better understanding of if and how EStim controls these changes, could lead to strategies that replace scarring with regeneration.

Osteomyelitis in limb amputated by amniotic band sequence.

A preterm (30+2 week) neonate with below-knee amputation (right lower limb), constriction rings and syndactyly, subsequent to amniotic band sequence, developed pus discharge from the right tibial stump. The neonate did not have clinical features of systemic sepsis. Blood culture was sterile. The pus culture, however, grew methicillin-resistant coagulase-negative Staphylococcus and bone scan was suggestive of osteomyelitis of right proximal tibial stump. Osteomyelitis was likely caused by the contiguous spread of infection from the exposed stump. Neonate was treated with intravenous antibiotics for 4 weeks and discharged on oral feeds.

Two for one: salvage of bilateral lower extremities with a single free flap.

It is thought that free muscle flaps may remain dependent on their original pedicle for more than 1-year postoperation, particularly in the lower extremity of patients with peripheral vascular disease. We present the first case report of bilateral lower extremity salvage with a single rectus abdominis myocutaneous free flap by transecting the main pedicle. The pedicle of the free flap, going to the contralateral extremity, was safely divided at 6-weeks postoperation. A tourniquet was used to compress the pedicle at the division point to assess viability of the flap distal to the point of occlusion prior to transection of the flap.

Residual limbs of amputees are significantly cooler than contralateral intact limbs.

OBJECTIVE: To test the hypothesis that distal residual limbs (DRLs) have significant vasomotor abnormalities. DESIGN: Comparative surface temperature studies of DRLs using paired samples (DRL vs. similar site on intact contralateral limb). SUBJECTS/PATIENTS: Thirty-six volunteer subjects with unilateral, upper or lower limb amputations were recruited and evaluated at a pain research center in an urban academic rehabilitation facility. METHODS: Our main outcomes were subjects' residual limb temperature as measured by quantitative infrared telethermography (qIRT), temperature strips, and examiner's palpation, compared with the contralateral limb. RESULTS: The qIRT showed that the DRLs were significantly cooler than the corresponding area of the contralateral intact limbs (P < 0.01). The difference using temperature strips supported this finding (P < 0.05); while on physical examination, 39% of the residual limbs were perceived by the examiner as cooler than the corresponding unaffected limbs. CONCLUSIONS: DRLs as measured by qIRT were significantly cooler than the corresponding area of the contralateral intact limbs. A better understanding of these findings may be important in elucidating the pathophysiology of relevant clinical features such as a potential sympathetic component of postamputation pain.

Femoral Artery Bypass Graft Pseudoaneurysm Rupture in a Transfemoral Amputee.

The case of a patient with an actively bleeding pseudoaneurysm associated with remnants of a polytetrafluoroethylene femoral bypass graft in his transfemoral residual limb is described. Initial graft placement was due to peripheral arterial disease. During subsequent transfemoral amputation, remnants of the nonpatent graft were retained in the residuum. After 4 yrs of lower limb prosthesis use, a proximal anastomosis pseudoaneurysm developed (with avulsion of graft remnants). The patient presented to clinic with a 5-day history of increased left groin fullness and largely nonradiating pain (rated 10/10). He was diagnosed with a pseudoaneurysm (1.9 cm) originating from the left common femoral artery and an associated hematoma (8 cm) on computed tomography; this required emergent reoperation. This case highlights the importance surrounding the decision to leave or explant neovascularization materials, which may carry significant risk for infection or physical disruption complications in residual limbs.