ABSTRACT
Over 185,000 limb amputations are performed in the United States annually, many of which are due to the sequelae of peripheral vascular disease. Symptomatic neuromas remain a significant source of postamputation morbidity and contribute to both phantom limb (PLP) and residual limb pain (RLP). While many interventions have been proposed for the treatment of symptomatic neuromas, conventional methods lead to a high incidence of neuroma recurrence. Furthermore, these existing methods do not facilitate an ability to properly interface with myoelectric prosthetic devices. The Regenerative Peripheral Nerve Interface (RPNI) was developed to overcome these limitations. The RPNI consists of an autologous free muscle graft secured around the end of a transected nerve. The muscle graft provides regenerating axons with end organs to reinnervate, thereby preventing neuroma formation. We have shown that this simple, reproducible, and safe surgical technique successfully treats and prevents neuroma formation in major limb amputations. In this paper, we describe RPNI surgery in the setting of major limb amputation and highlight the promising results of RPNIs in our animal and clinical studies.
Subject(s)
Amputation, Surgical , Leg/surgery , Muscle, Skeletal/surgery , Nerve Regeneration , Neuroma/prevention & control , Pain, Postoperative/prevention & control , Peripheral Nerves/surgery , Amputation, Surgical/adverse effects , Humans , Leg/innervation , Muscle, Skeletal/innervation , Neuroma/etiology , Neuroma/physiopathology , Pain, Postoperative/etiology , Pain, Postoperative/physiopathology , Peripheral Nerves/physiopathology , Transplantation, Autologous , Treatment OutcomeABSTRACT
Peripheral nerve injury remains a major cause of morbidity in trauma patients. Despite advances in microsurgical techniques and improved understanding of nerve regeneration, obtaining satisfactory outcomes after peripheral nerve injury remains a difficult clinical problem. There is a growing body of evidence in preclinical animal studies demonstrating the supportive role of stem cells in peripheral nerve regeneration after injury. The characteristics of both mesoderm-derived and ectoderm-derived stem cell types and their role in peripheral nerve regeneration are discussed, specifically focusing on the presentation of both foundational laboratory studies and translational applications. The current state of clinical translation is presented, with an emphasis on both ethical considerations of using stems cells in humans and current governmental regulatory policies. Current advancements in cell-based therapies represent a promising future with regard to supporting nerve regeneration and achieving significant functional recovery after debilitating nerve injuries.
Subject(s)
Nerve Regeneration/physiology , Peripheral Nerve Injuries/therapy , Peripheral Nerves/physiology , Stem Cell Transplantation , Humans , Recovery of Function/physiologyABSTRACT
BACKGROUND: Prolonged cold ischemia associated with static cold storage (SCS) results in higher incidence of acute and chronic allograft rejection in solid organ transplantations. Deleterious effects of SCS on vascularized composite tissue allograft were studied with limited data on muscle structure and function. The aim of this study is to evaluate the long-term impact of SCS on muscle metabolism, structure, and force generation using a syngeneic rat hindlimb transplantation model. METHODS: Sixty-five male Lewis rats (250 ± 25 g) were distributed into five groups, including naive control, sciatic nerve denervation/repair, immediate transplantation, transplantation following static warm storage for 6 hours at room temperature, and transplantation following SCS for 6 hours at 4°C. Sciatic nerves were repaired in all transplantations. Muscle samples were taken for histology and metabolomics analysis following electromyography and muscle force measurements at 12 weeks after transplantation. RESULTS: All cold-preserved limbs remained viable at 12 weeks, whereas animals receiving limbs preserved in room temperature had no survivors. The SCS transplantation group showed a 73% injury score, significantly higher than groups receiving immediate transplants without cold preservation (50%, p < 0.05). A significant decline in muscle contractile force was also demonstrated in comparison to the immediate transplantation group (p < 0.05). In the SCS group, muscle energy reserves remained relatively well preserved in surviving fibers. CONCLUSION: SCS extends allograft survival but fails to preserve muscle structure and force.
Subject(s)
Cold Ischemia/adverse effects , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Organ Preservation/adverse effects , Vascularized Composite Allotransplantation , Animals , Cryopreservation/methods , Disease Models, Animal , Electromyography , Graft Survival/physiology , Hindlimb/transplantation , Male , Metabolomics , Muscle Contraction/physiology , Muscle Strength/physiology , Rats , Rats, Inbred Lew , Reperfusion Injury/complications , Sciatic Neuropathy/etiology , Sciatic Neuropathy/pathology , Vascularized Composite Allotransplantation/adverse effects , Vascularized Composite Allotransplantation/methodsABSTRACT
BACKGROUND: Morphomic studies have demonstrated a correlation between sarcopenia and clinical outcomes in septic patients. However, tendon morphomics has not yet been studied in this context. The purpose of the present study was to evaluate tendon morphology in septic patients through analytic morphomics. We hypothesized that morphomic analyses would reveal concomitant muscle and tendon wasting in sepsis patients. The results of this study may help to implement different rehabilitation modalities for critically ill patients. MATERIALS AND METHODS: The volume and fat content of bilateral psoas muscles and tendons were measured on abdominal computed tomography scans of 25 ICU septic and 25 control trauma patients admitted to the University of Michigan between 2011 and 2012. Univariate and multivariate analyses were performed to determine the relationship between psoas muscle and tendon morphometric data, and the association with clinical variables such as smoking and comorbidities. RESULTS: Average psoas muscle volume was 12.21 ± 5.6 cm3 for control patients and 9.318 ± 3.3 cm3 in septic patients (P = 0.0023). The average psoas muscle/fat ratio for septic patients was 0.0288 ± 0.071 cm3, compared with 0.0107 ± 0.008 cm3 in the control group (P = 0.075). Average tendon volume in the septic population (0.508 ± 0.191 cm3) was not different than the control cohort (0.493 ± 0.182 cm3) (P = 0.692). CONCLUSIONS: Our results demonstrate significantly smaller psoas muscle volume in septic patients than in age-, gender-, and BMI-matched trauma patients but no demonstrable change in tendon morphology between patient groups. These findings begin to define the boundaries of clinical application within the field of morphomics.
Subject(s)
Muscular Atrophy/diagnostic imaging , Psoas Muscles/diagnostic imaging , Sepsis/complications , Tendons/diagnostic imaging , Tomography, X-Ray Computed , Acute Disease , Adult , Aged , Critical Illness , Female , Humans , Male , Middle Aged , Multivariate Analysis , Muscular Atrophy/etiology , Muscular Atrophy/pathology , Organ Size , Psoas Muscles/pathology , Retrospective Studies , Risk Factors , Tendons/pathologyABSTRACT
Purpose: Although incivility has been described in other specialties, little is known about the attributes and perpetrators of it in academic surgery. The goal of this study was to identify attributes and commonly associated perpetrators of incivility experienced by trainees and faculty at academic surgery programs in the U.S. Methods: A web-based survey including the Workplace Incivility Scale (WIS) and questions regarding attributions and perpetrators of incivility was sent to trainees and faculty at academic institutions across the U.S. In addition to descriptive statistics, multivariable regression models were built to determine the impact of perpetrator type and number on overall incivility scores. Results: We received 367 of 2,661 (13.8%) responses. Top three reasons for incivility were surgery hierarchy (50.1%), respondent's gender (33.8%) and intergenerational differences (28.1%). Faculty (58.6%), patients (36.8%), and nursing staff (31.9%) were the most reported parties responsible for incivility. Female surgeons reported experiencing incivility more frequently from all three top responsible parties (i.e., faculty, patients, and nurses) when compared to other gender identities. Additionally, those who reported faculty (ß = 0.61, 95%CI 0.39-0.82) or nurses (ß = 0.23, 95%CI 0.009-0.45) as perpetrators of incivility reported an increase in overall incivility scores. Conclusions: Incivility in surgery is frequently attributed to surgery hierarchy, gender, and intergenerational differences. Surgical trainees and faculty reported that faculty, patients, and nurses were the most commonly identified as responsible for uncivil events in the surgical workforce. Exposure to a greater variety of perpetrators of incivility increases overall levels of incivility, emphasizing the importance of eliminating incivility from all sources. Supplementary Information: The online version contains supplementary material available at 10.1007/s44186-023-00129-1.
ABSTRACT
Background and Objective: Breast reconstruction in patients with obesity presents numerous challenges, both in terms of surgical technique and post-operative complication management. As breast reconstruction techniques continue to evolve, the armamentarium of reconstructive options for patients with obesity has vastly expanded. Options now include immediate or delayed, implant-based, autologous, or hybrid reconstruction. Determining the optimal breast reconstruction in this complex population requires nuanced and experienced decision-making. Methods: A literature search was conducted to identify studies assessing breast reconstruction considerations in patients with obesity. The search was performed on PubMed and was limited to English language studies published between 1990 and 2023. Primary studies, case reports, chart reviews, and qualitative studies were included. Additional articles were identified for inclusion based on a review of references, as well as a web-based search, to identify additional studies that were not captured with the primary search strategy. Key Content and Findings: This narrative review article summarizes the current literature available to guide surgeons in breast reconstruction in patients with obesity. Conclusions: The advancements in oncologic surgery and breast reconstruction techniques have expanded available surgical options, including immediate or delayed implant-based, autologous, or hybrid breast reconstruction. Each approach has its unique advantages, disadvantages, and surgical considerations. Despite the challenges, patients with obesity can achieve favorable aesthetic outcomes through careful assessment of comorbidities and expectation management.
ABSTRACT
BACKGROUND: Without meaningful, intuitive sensory feedback, even the most advanced myoelectric devices require significant cognitive demand to control. The dermal sensory regenerative peripheral nerve interface (DS-RPNI) is a biological interface designed to establish high-fidelity sensory feedback from prosthetic limbs. METHODS: DS-RPNIs were constructed in rats by securing fascicles of residual sensory peripheral nerves into autologous dermal grafts, with the objectives of confirming regeneration of sensory afferents within DS-RPNIs and establishing the reliability of afferent neural response generation with either mechanical or electrical stimulation. RESULTS: Two months after implantation, DS-RPNIs were healthy and displayed well-vascularized dermis with organized axonal collaterals throughout and no evidence of neuroma. Electrophysiologic signals were recorded proximal from DS-RPNI's sural nerve in response to both mechanical and electrical stimuli and compared with (1) full-thickness skin, (2) deepithelialized skin, and (3) transected sural nerves without DS-RPNI. Mechanical indentation of DS-RPNIs evoked compound sensory nerve action potentials (CSNAPs) that were like those evoked during indentation of full-thickness skin. CSNAP firing rates and waveform amplitudes increased in a graded fashion with increased mechanical indentation. Electrical stimuli delivered to DS-RPNIs reliably elicited CSNAPs at low current thresholds, and CSNAPs gradually increased in amplitude with increasing stimulation current. CONCLUSIONS: These findings suggest that afferent nerve fibers successfully reinnervate DS-RPNIs, and that graded stimuli applied to DS-RPNIs produce proximal sensory afferent responses similar to those evoked from normal skin. This confirmation of graded afferent signal transduction through DS-RPNI neural interfaces validate DS-RPNI's potential role of facilitating sensation in human-machine interfacing. CLINICAL RELEVANCE STATEMENT: The DS-RPNI is a novel biotic-abiotic neural interface that allows for transduction of sensory stimuli into neural signals. It is expected to advance the restoration of natural sensation and development of sensorimotor control in prosthetics.
Subject(s)
Feedback, Sensory , Peripheral Nerves , Rats , Humans , Animals , Feedback , Reproducibility of Results , Peripheral Nerves/physiology , Sural Nerve , Nerve Regeneration/physiologyABSTRACT
Background: Opioid misuse after surgery remains a public health crisis in the United States. Recent efforts have focused on tracking pain medication use in surgical populations. However, accurate interpretations of medication use remain quite challenging given inconsistent usage of different datasets. The purpose of this study was to investigate the agreement between electronic medical records (EMR) versus patient self-reported use of pain medications in a surgical amputation population. Methods: Patients undergoing major lower extremity amputation or amputation-related procedures were included in this study. Both self-reported and EMR data for pain medication intake were obtained for each patient at three time points (preoperatively, 4 months postoperatively, and 12 months postoperatively). Percentage agreement and the kappa statistic were calculated for both usage (yes/no) and dose categories. Results: Forty-five patients were included in this study, resulting in 108 pairs of self-reported and EMR datasets. Substantial levels of agreement (>70% agreement, kappa >0.61) for opioid use was seen at preoperative and 12 months postoperative. However, agreement dropped at 4 months postoperatively. Anticonvulsant medication showed high levels, whereas acetaminophen showed lower levels of agreements at all time points. Conclusions: Either self-reported or EMR data may be used in research and clinical settings for preoperative or 12-month postoperative patients with little concern for discrepancies. However, at time points immediately following the expected end of acute surgical pain, self-reported data may be needed for more accurate medication reporting. With these findings in mind, usage of datasets should be driven by study objectives and the dataset's strength (eg, accuracy, ease, lack of bias).
ABSTRACT
We present a case report examining the clinical management of tenosynovitis with psammomatous calcifications presenting like pyogenic flexor tenosynovitis in a pregnant patient. Discussion details overlapping symptoms, important distinctions on imaging studies and the appropriateness of surgery. Level of Evidence: Level V (Therapeutic).
Subject(s)
Tenosynovitis , Humans , Tenosynovitis/diagnosis , Tenosynovitis/surgeryABSTRACT
Background. Robotic exoskeleton devices have become a promising modality for restoration of extremity function in individuals with limb loss or functional weakness. However, there exists no consistent or reliable way to record efferent motor action potentials from intact peripheral nerves to control device movement. Peripheral nerve motor action potentials are similar in amplitude to that of background noise, producing an unfavorable signal-to-noise ratio (SNR) that makes these signals difficult to detect and interpret. To address this issue, we have developed the muscle cuff regenerative peripheral nerve interface (MC-RPNI), a construct consisting of a free skeletal muscle graft wrapped circumferentially around an intact peripheral nerve. Over time, the muscle graft regenerates, and the intact nerve undergoes collateral axonal sprouting to reinnervate the muscle. The MC-RPNI amplifies efferent motor action potentials by several magnitudes, thereby increasing the SNR, allowing for higher fidelity signaling and detection of motor intention. The goal of this study was to characterize the signaling capabilities and viability of the MC-RPNI over time.Methods. Thirty-seven rats were randomly assigned to one of five experimental groups (Groups A-E). For MC-RPNI animals, their contralateral extensor digitorum longus (EDL) muscle was harvested and trimmed to either 8 mm (Group A) or 13 mm (Group B) in length, wrapped circumferentially around the intact ipsilateral common peroneal (CP) nerve, secured, and allowed to heal for 3 months. Additionally, one 8 mm (Group C) and one 13 mm (Group D) length group had an epineurial window created in the CP nerve immediately preceding MC-RPNI creation. Group E consisted of sham surgery animals. At 3 months, electrophysiologic analyses were conducted to determine the signaling capabilities of the MC-RPNI. Additionally, electromyography and isometric force analyses were performed on the CP-innervated EDL to determine the effects of the MC-RPNI on end organ function. Following evaluation, the CP nerve, MC-RPNI, and ipsilateral EDL muscle were harvested for histomorphometric analysis.Results. Study endpoint analysis was performed at 3 months post-surgery. All rats displayed visible muscle contractions in both the MC-RPNI and EDL following proximal CP nerve stimulation. Compound muscle action potentials were recorded from the MC-RPNI following proximal CP nerve stimulation and ranged from 3.67 ± 0.58 mV to 6.04 ± 1.01 mV, providing efferent motor action potential amplification of 10-20 times that of a normal physiologic nerve action potential. Maximum tetanic isometric force (Fo) testing of the distally-innervated EDL muscle in MC-RPNI groups producedFo(2341 ± 114 mN-2832 ± 102 mN) similar to controls (2497 ± 122 mN), thus demonstrating that creation of MC-RPNIs did not adversely impact the function of the distally-innervated EDL muscle. Overall, comparison between all MC-RPNI sub-groups did not reveal any statistically significant differences in signaling capabilities or negative effects on distal-innervated muscle function as compared to the control group.Conclusions. MC-RPNIs have the capability to provide efferent motor action potential amplification from intact nerves without adversely impacting distal muscle function. Neither the size of the muscle graft nor the presence of an epineurial window in the nerve had any significant impact on the ability of the MC-RPNI to amplify efferent motor action potentials from intact nerves. These results support the potential for the MC-RPNI to serve as a biologic nerve interface to control advanced exoskeleton devices.
Subject(s)
Nerve Regeneration , Peripheral Nerves , Animals , Electromyography , Muscle Contraction , Muscle, Skeletal , Rats , Rats, Inbred F344ABSTRACT
BACKGROUND: Previous investigators demonstrated that female patients often prefer female providers. However, these studies have not determined whether there are gender preferences for breast reconstruction surgeons or whether the effects of surgeon gender impacts patient-reported outcomes. METHODS: Adult women were crowdsourced using Amazon Mechanical Turk to characterize societal preferences for the gender of breast and plastic surgeons in a hypothetical scenario. The authors also used data from the Mastectomy Reconstruction Outcomes Consortium to determine the association between surgeon gender and patient satisfaction after breast reconstruction. The BREAST-Q questionnaire was used to assess patient-reported outcomes at 3 months and 2 years following reconstruction. Regression analyses were performed to investigate the effects of surgeon gender on patient-reported outcomes. RESULTS: In total, 1413 surveys were collected. Forty-two percent preferred female plastic surgeons, 5 percent preferred male surgeons, and 53 percent reported no preference. The Mastectomy Reconstruction Outcomes Consortium analysis included 2236 patients of 55 male and nine female plastic surgeons. In this cohort, 1921 patients (82.2 percent) had male surgeons, whereas 415 patients (17.8 percent) had female surgeons. Regression analysis at 2 years revealed no differences in satisfaction with surgeon, outcome, or psychosocial well-being. Only satisfaction with information differed, as patients of female surgeons reported greater satisfaction in this category, with an adjusted mean difference of 2.82 (p = 0.018). CONCLUSIONS: Although nonpatient women hypothetically prefer female providers, surgeon gender makes little difference in actual patient satisfaction with breast reconstruction. More investigation is needed to determine whether the difference in information delivery is clinically significant and whether it reflects variations in practices between male and female surgeons. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.
Subject(s)
Mammaplasty/psychology , Mastectomy/adverse effects , Patient Reported Outcome Measures , Physicians, Women/statistics & numerical data , Surgeons/statistics & numerical data , Adult , Breast Neoplasms/surgery , Female , Humans , Male , Mammaplasty/statistics & numerical data , Middle Aged , Patient Preference/statistics & numerical data , Patient Satisfaction/statistics & numerical data , Perception , Sex FactorsABSTRACT
Pain is a central feature of soft tissue trauma, which under certain contexts, results in aberrant osteochondral differentiation of tissue-specific stem cells. Here, the role of sensory nerve fibers in this abnormal cell fate decision is investigated using a severe extremity injury model in mice. Soft tissue trauma results in NGF (Nerve growth factor) expression, particularly within perivascular cell types. Consequently, NGF-responsive axonal invasion occurs which precedes osteocartilaginous differentiation. Surgical denervation impedes axonal ingrowth, with significant delays in cartilage and bone formation. Likewise, either deletion of Ngf or two complementary methods to inhibit its receptor TrkA (Tropomyosin receptor kinase A) lead to similar delays in axonal invasion and osteochondral differentiation. Mechanistically, single-cell sequencing suggests a shift from TGFß to FGF signaling activation among pre-chondrogenic cells after denervation. Finally, analysis of human pathologic specimens and databases confirms the relevance of NGF-TrkA signaling in human disease. In sum, NGF-mediated TrkA-expressing axonal ingrowth drives abnormal osteochondral differentiation after soft tissue trauma. NGF-TrkA signaling inhibition may have dual therapeutic use in soft tissue trauma, both as an analgesic and negative regulator of aberrant stem cell differentiation.
Subject(s)
Cell Differentiation , Nerve Growth Factor/metabolism , Receptor, trkA/metabolism , Signal Transduction , Wounds and Injuries/metabolism , Animals , Axons/metabolism , Cartilage/metabolism , Mice , Mice, Inbred C57BL , Nerve Growth Factor/genetics , Osteogenesis , Stem Cells/metabolism , Wounds and Injuries/pathologyABSTRACT
BACKGROUND: Postamputation pain affects a large number of individuals living with major limb loss. Regenerative peripheral nerve interfaces are constructs composed of a transected peripheral nerve implanted into an autologous free muscle graft. The authors have previously shown that regenerative peripheral nerve interfaces can be used to treat symptomatic end neuromas that develop after major limb amputation. In this study, they investigated the potential of prophylactic interfaces to prevent the formation of symptomatic neuromas and mitigate phantom limb pain. METHODS: Patients who underwent limb amputation with and without prophylactic regenerative peripheral nerve interface implantation were identified. A retrospective review was performed to ascertain patient demographics, level of amputation, and postoperative complications. Documentation of symptomatic neuromas and phantom limb pain was noted. RESULTS: Postoperative outcomes were evaluated in a total of 90 patients. Forty-five patients underwent interface implantation at the time of primary amputation, and 45 control patients underwent amputation without interfaces. Six control patients (13.3 percent) developed symptomatic neuromas in the postoperative period compared with zero (0.0 percent) in the prophylactic interface group (p = 0.026). Twenty-three interface patients (51.1 percent) reported phantom limb pain, compared with 41 control patients (91.1 percent; p < 0.0001). CONCLUSIONS: Prophylactic regenerative peripheral nerve interfaces in major limb amputees resulted in a lower incidence of both symptomatic neuromas and phantom limb pain compared with control patients undergoing amputation without regenerative peripheral nerve interfaces, suggesting that prevention of peripheral neuromas following amputation may diminish the central pain mechanisms that lead to phantom limb pain. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.
Subject(s)
Amputation, Surgical/adverse effects , Nerve Regeneration , Neuroma/epidemiology , Peripheral Nerves/transplantation , Phantom Limb/prevention & control , Adolescent , Adult , Aged , Amputation, Surgical/methods , Amputation Stumps/innervation , Case-Control Studies , Child , Female , Humans , Incidence , Male , Middle Aged , Neuroma/etiology , Peripheral Nerves/physiology , Phantom Limb/epidemiology , Phantom Limb/etiology , Retrospective Studies , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Aesthetic facial contouring procedures, particularly forehead augmentation, continue to increase in popularity in the Asian population. However, there are very few reports in the literature specifically examining the long-term outcomes of forehead fat grafting. In the present study, the authors aimed to objectively evaluate the efficacy of autologous forehead fat grafting through evaluation of facial proportions and patient-reported outcomes. METHODS: Patients who underwent autologous fat grafting for forehead contouring procedures between July of 2011 and June of 2017 were recruited for participation in the study. Patient demographic and clinical variables were collected preoperatively and postoperatively. Facial proportion analysis was collected and compared from preoperative and postoperative photographs. Satisfaction with outcome was assessed by the patient, the surgeon, and a layperson postoperatively. A related-samples Wilcoxon signed rank test was used for statistical analysis. RESULTS: Postoperative outcomes were evaluated in a total of 24 patients who underwent forehead autologous fat-grafting procedures. The average postoperative follow-up was 8.1 months. There were no intraoperative or postoperative complications. More than 50 percent of the postoperative results were evaluated as "satisfactory" by all three groups (i.e., patient, surgeon, and layperson) in terms of aesthetic contouring. Average forehead projection increased 0.24 U (ratio of horizontal distance from midforehead plane to cornea plane/cornea diameter) after one round of fat grafting (p = 0.01). Seven patients (29.2 percent) required more than a single round of fat grafting to achieve optimal results. CONCLUSIONS: Autologous fat grafting remains a viable option for forehead contouring and augmentation. The findings of this study demonstrate that the operation is effective and offers stable satisfactory results after long-term follow-up. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
Subject(s)
Adipose Tissue/transplantation , Asian People/statistics & numerical data , Forehead/surgery , Surgery, Plastic/methods , Adult , Body Contouring/methods , Cohort Studies , Female , Graft Rejection , Graft Survival , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Prognosis , Retrospective Studies , Statistics, Nonparametric , Transplantation, Autologous , Treatment OutcomeABSTRACT
BACKGROUND: Upper limb loss is a devastating condition with dramatic physical, psychological, financial, and social consequences. Improvements in the fields of prosthetics and vascularized composite allotransplantation have opened exciting new frontiers for treatment and rehabilitation following upper limb loss. Each modality offers a unique set of advantages and limitations with regard to the restoration of hand function following amputation. METHODS: Presented in this article is a discussion outlining the complex considerations and decisions encountered when determining patient appropriateness for either prosthetic rehabilitation or vascularized composite allotransplantation following upper limb loss. In this review, the authors examine how psychosocial factors, nature of injury, rehabilitation course, functional outcomes, and risks and benefits may affect overall patient selection for either rehabilitative approach. RESULTS: This review summarizes the current state of the literature. Advancements in both prosthetic and biological strategies demonstrate promise with regard to facilitating rehabilitation following upper limb loss. However, there remains a dearth of research directly comparing outcomes in prosthetic rehabilitation to that following upper extremity transplantation. CONCLUSIONS: Few studies have performed a direct comparison between patients undergoing vascularized composite allotransplantation and those undergoing prosthetic rehabilitation. Upper extremity transplantation and prosthetic reconstruction should not be viewed as competing options, but rather as two treatment modalities with different risk-to-benefit profiles and indications.
Subject(s)
Amputation, Surgical/rehabilitation , Amputees/rehabilitation , Artificial Limbs , Quality of Life , Upper Extremity/surgery , Vascularized Composite Allotransplantation/methods , Amputation, Surgical/methods , Amputees/psychology , Decision Making , Female , Follow-Up Studies , Humans , Male , Patient Selection , Prosthesis Fitting , Risk Assessment , Treatment OutcomeABSTRACT
BACKGROUND: Hypothermic ex situ perfusion (HESP) systems are used to prolong allograft survival in solid organ transplantations and have been shown to be superior to static cold storage (SCS) methods. However, the effect of this preservation method on limb allograft survival and long-term function has not yet been tested. In this study, we investigated the long-term effects of the HESP on skeletal muscle metabolism, structure, and force generation and compared it with the current standard of preservation. METHODS: Forty male Lewis rats (250 ± 25 g) were divided into 5 groups, including naive control, sciatic nerve transection or repair, immediate transplantation, SCS, and HESP. For the SCS group, limbs were preserved at 4°C for 6 hours. In the HESP group, limbs were continuously perfused with oxygenated histidine-tryptophan-ketoglutarate (HTK) solution at 10-15°C for 6 hours. Hemodynamic and biochemical parameters of perfusion were recorded throughout the experiment. At 12 weeks, electromyography and muscle force measurements (maximum twitch and tetanic forces) were obtained along with muscle samples for histology and metabolomics analysis. RESULTS: Histology demonstrated 48% myocyte injury in the HESP group compared with 49% in immediate transplantation (P = 0.96) and 74% in the SCS groups (P < 0.05). The maximum twitch force measurement revealed a significantly higher force in the HESP group compared with the SCS group (P = 0.029). Essential amino acid levels of the gastrocnemius muscle did not reach significance, with the exception of higher proline levels in the HESP group. CONCLUSIONS: HESP using HTK protects viability of the limb but fails to restore muscle force in the long term.
Subject(s)
Hindlimb/surgery , Muscle, Skeletal/transplantation , Organ Preservation/methods , Perfusion/methods , Replantation/methods , Amputation, Traumatic/surgery , Animals , Cold Ischemia/adverse effects , Cold Ischemia/methods , Disease Models, Animal , Glucose/administration & dosage , Hindlimb/injuries , Humans , Male , Mannitol/administration & dosage , Muscle Strength , Muscle, Skeletal/blood supply , Muscle, Skeletal/metabolism , Muscle, Skeletal/ultrastructure , Organ Preservation/adverse effects , Organ Preservation Solutions/administration & dosage , Perfusion/adverse effects , Potassium Chloride/administration & dosage , Procaine/administration & dosage , Rats , Rats, Inbred Lew , Time FactorsABSTRACT
BACKGROUND: Peripheral nerve injuries remain a major clinical concern, as they often lead to chronic disability and significant health care expenditures. Despite advancements in microsurgical techniques to enhance nerve repair, biological approaches are needed to augment nerve regeneration and improve functional outcomes after injury. METHODS: Presented herein is a review of the current literature on state-of-the-art techniques to enhance functional recovery for patients with nerve injury. Four categories are considered: (1) electroceuticals, (2) nerve guidance conduits, (3) fat grafting, and (4) optogenetics. Significant study results are highlighted, focusing on histologic and functional outcome measures. RESULTS: This review documents the current state of the literature. Advancements in neuronal stimulation, tissue engineering, and cell-based therapies demonstrate promise with regard to augmenting nerve regeneration and appropriate rehabilitation. CONCLUSIONS: The future of treating peripheral nerve injury will include multimodality use of electroconductive conduits, fat grafting, neuronal stimulation, and optogenetics. Further clinical investigation is needed to confirm the efficacy of these technologies on peripheral nerve recovery in humans, and how best to implement this treatment for a diverse population of nerve-injured patients.