Plastic and Reconstructive Surgery - Global Open, 2016
With rising cost of healthcare, there is an urgent need for developing effective and economical s... more With rising cost of healthcare, there is an urgent need for developing effective and economical streamlined care. In clinical situations with limited data or conflicting evidence-based data, there is significant institutional and individual practice variation. Quality improvement with the use of Standardized Clinical Assessment and Management Plans (SCAMPs) might be beneficial in such scenarios. The SCAMPs method has never before been reported to be utilized in plastic surgery. The topic of immediate breast reconstruction was identified as a possible SCAMPs project. The initial stages of SCAMPs development, including planning and implementation, were entered. The SCAMP Champion, along with the SCAMPs support team, developed targeted data statements. The SCAMP was then written and a decision-tree algorithm was built. Buy-in was obtained from the Division of Plastic Surgery and a SCAMPs data form was generated to collect data. Decisions pertaining to "immediate implant-based brea...
Plastic and reconstructive surgery. Global open, 2015
With rising cost of healthcare, there is an urgent need for developing effective and economical s... more With rising cost of healthcare, there is an urgent need for developing effective and economical streamlined care. In clinical situations with limited data or conflicting evidence-based data, there is significant institutional and individual practice variation. Quality improvement with the use of Standardized Clinical Assessment and Management Plans (SCAMPs) might be beneficial in such scenarios. The SCAMPs method has never before been reported to be utilized in plastic surgery. The topic of immediate breast reconstruction was identified as a possible SCAMPs project. The initial stages of SCAMPs development, including planning and implementation, were entered. The SCAMP Champion, along with the SCAMPs support team, developed targeted data statements. The SCAMP was then written and a decision-tree algorithm was built. Buy-in was obtained from the Division of Plastic Surgery and a SCAMPs data form was generated to collect data. Decisions pertaining to "immediate implant-based brea...
Plastic and Reconstructive Surgery - Global Open, 2015
Rhinoplasty in middle-aged and elderly patients comes with its own set of challenges. There is re... more Rhinoplasty in middle-aged and elderly patients comes with its own set of challenges. There is relative lengthening of the nose with drooping of the nasal tip. With aging, the skin loses its elasticity, and the combination of nasal skeletal reduction along with overlying inelastic skin provides a setup for skin redundancy and poor postoperative outcome. We describe a surgical technique involving lenticular skin excision as a part of rhinoplasty in 12 patients older than 50 years to improve the aesthetic outcome. Skin width up to 1.6 cm was excised. Included is a literature review of skin excision in rhinoplasty. In elderly patients with thin, inelastic skin and long nose with a drooping tip, a reduction rhinoplasty technique might result in skin redundancy. Lenticular skin excision along the radix of the nose in these 12 patients improved the aesthetic outcome by decreasing the redundancy and preventing nasal tip ptosis. The wound from the skin resection healed in all the patients with minimal scar, and no complication was noted after at least 1 year of follow-up for each patient.
Palatal fistula is a known complication of cleft lip-cleft palate repair. Fistulas anterior to th... more Palatal fistula is a known complication of cleft lip-cleft palate repair. Fistulas anterior to the incisive foramen can be particularly difficult to repair because of the lack of available tissue. Adjacent tissue has inherent limitations, and multiple free-flap techniques have been described; however, there remains no single solution for this difficult problem. The authors present an alternative strategy of replacing "like with like" by using an osteocutaneous free tissue transfer of the second toe for anterior oronasal fistulas. Use of the osteocutaneous second-toe free flap provides skin lining to both the oral side and the nasal side to close oronasal fistulas. It also bridges the alveolar gap with vascularized bone. This flap can be considered as an elegant alternative for anterior oronasal fistulas.
Abdominoplasty is being increasingly performed as an outpatient procedure. The role of tumescent ... more Abdominoplasty is being increasingly performed as an outpatient procedure. The role of tumescent technique in decreasing postoperative pain and hospital stay has not been extensively studied. We reviewed 65 consecutive patients who underwent tumescent abdominoplasty over 20 months by a single surgeon. All the patients were followed up for at least 1 year. The outcomes were evaluated in terms of systemic complications such as deep vein thrombosis and pulmonary embolism and local complications such as seroma, wound infection, and skin necrosis. Of the 65 patient records analyzed, 61 were of females and 4 of males. Average age for the patient population was 45.2 years. Mean follow-up was at least 1 year for all the patients. Ninety-five percent of patients could be discharged the same day with tumescent abdominoplasty, whereas 71% of the patients who underwent concurrent procedures with abdominoplasty were also able to go home the same day. All the patients reported excellent postopera...
The etiology, clinical impact, natural history and best therapy of unilateral diaphragm paralysis... more The etiology, clinical impact, natural history and best therapy of unilateral diaphragm paralysis (UDP) are incompletely understood. This condition is not amenable to pacing, which requires an intact phrenic nerve. Clinical records of patients with UDP referred to our diaphragm center were reviewed. Thirty-six patients (28 male, 8 female) aged 1 month to 78 years (mean 47.8 years) with UDP evaluated from 1983 to February 2007 were reviewed. Etiology was postsurgical in 13 (36%), tumor (with surgery or radiation therapy) in 7 (19%), idiopathic in 6 (17%), trauma (motor vehicle accident or head injury) in 5 (14%), polio in 3 (8%), and viral in 2 (6%) patients. 28 patients (78%) were symptomatic; 8 (22%) carried a diagnosis of coexisting chronic obstructive pulmonary disease. Mean duration of paralysis was 57.9 months (range up to 261 months). The left diaphragm was involved in 23 cases (64%) and the right in 13 (36%). Mean forced expiratory volume (FEV1) was 1 915 mL (61.3% of predict...
Immediate reconstruction of perineal defects secondary to abdominoperineal resection (APR) or pel... more Immediate reconstruction of perineal defects secondary to abdominoperineal resection (APR) or pelvic exenteration with pedicled flaps decreases post-operative wound complications when compared with direct closure in high-risk patients. While prior authors have been proponents of abdominal-based flaps, here we evaluate the role for thigh-based flaps founded on acceptable outcomes and low morbidity. Consecutive patients referred to a single surgeon between January 2012 and August 2015 who underwent perineal reconstruction with a pedicled gracilis flap were identified. Patients were evaluated for routine pre-operative variables and outcome data analyzed, including time to healing and abdominal and perineal complications. Forty patients were included in the study, with a mean follow-up period of 2 years. There was no 30-day mortality and 37 patients (92.5%) were alive at the last follow-up. Five patients (12.5%) experienced donor-site complications while 16 patients (40%) had recipient-site complications, including hematoma, seroma, or dehiscence. Minor complications were seen in 10 (25%) patients while 7 (17.5%) patients had major complications. Obesity (OR 7.5, p=0.01), and active smoking status (OR 9.3, p=0.01) were significantly associated with minor complications; while a history of neo-adjuvant chemoradiation (OR 21.4, p=0.04) was a significant risk factor for any complication. The overall complication rate with this technique is comparable to the more commonly used VRAM flap but the potential for, and severity of, donor site complications is reduced with this technique. As such, gracilis flaps may be considered an acceptable alternative to abdominal flaps for selected perineal wounds.
Wound healing is traditionally divided into inflammation, proliferation and remodelling phases. S... more Wound healing is traditionally divided into inflammation, proliferation and remodelling phases. Several inflammatory mediators and cells regulate the inflammation phase. The specific roles for different mediators have not been clearly defined. The effects of inflammation phase modulation on wound healing were evaluated in this study. Rat full-thickness wounds were divided into different experimental groups: a) sterile hyper-inflammatory wounds/endotoxin (topical endotoxin), b) sterile hypo-inflammatory/inhibitor group (cocktail of topical COX-1 plus COX-2 plus lipoxygenase inhibitors) c) control groups: topical saline or DMSO. After full-thickness wound creation, custom-made titanium chambers enclosed the wound, creating an isolated well-controlled environment. Wound healing was followed over time; tissue biopsies and wound fluid samples were collected on days 1, 4 and 8 postoperatively.The validity of the inflammation model was confirmed by increased IL-1a expression, increased CD45+ leukocytes recruitment in the hyper-inflamed group as compared to the inhibitor and control groups. The re-epithelialization percentage was significantly increased in the endotoxin group as compared to the inhibitor group on Day 4 (60.75 vs. 22.05, p-value <0.05) and both the inhibitor and the control group on Day 8 (Control Group - 63.2%, Inhibitor Group - 28.9%, Endotoxin Group - 84.2%,p-value <0.05) . Also, the macroscopic wound closure was increased in the endotoxin group as compared to the inhibitor group and control group both on Day 4 (Control Group - 69.9%, Inhibitor Group - 62.9%, Endotoxin Group - 81.9%, p-value <0.05) and on Day 8 (Control Group - 68.5%, Inhibitor Group - 69.1%, Endotoxin Group - 83.7%, p-value <0.05). Endotoxin-induced sterile inflammation up regulates IL-1a expression and CD45+ leukocyte recruitment and results in faster rate of wound re-epithelialization and wound closure in full-thickness rodent wounds. Conversely, the wound re-epithelialization and wound closure can be significantly delayed on treatment with a combination of cyclooxygenase and lipoxygenase inhibitors. This article is protected by copyright. All rights reserved.
"Medical tourism&amp... more "Medical tourism" has gained popularity over the past few decades. This is particularly common with patients seeking elective cosmetic surgery in the developing world. However, the risk of severe and unusual infectious complications appears to be higher than for patients undergoing similar procedures in the United States. The authors describe their experience with atypical mycobacterial infections in cosmetic surgical patients returning to the United States postoperatively. A review of patient medical records presenting with infectious complications after cosmetic surgery between January 2010 and July 2015 was performed. Patients presenting with mycobacterial infections following cosmetic surgery were reviewed in detail. An extensive literature review was performed for rapid-growing mycobacteria (RGM) related to cosmetic procedures. Between January 2010 and July 2015, three patients presented to our institution with culture-proven Mycobacterium abscessus at the sites of recent cosmetic surgery. All had surgery performed in the developing world. The mean age of these patients was 36 years (range, 29-44 years). There was a delay of up to 16 weeks between the initial presentation and correct diagnosis. All patients were treated with surgical drainage and combination antibiotics with complete resolution. We present series of patients with mycobacterial infections after cosmetic surgery in the developing world. This may be related to the endemic nature of these bacteria and/or inadequate sterilization or sterile technique. Due to low domestic incidence of these infections, diagnosis may be difficult and/or delayed. Consulting physicians should have a low threshold to consider atypical etiologies in such scenarios. 5 Therapeutic.
Although rodent models have been used extensively for surgical research, their use is limited in ... more Although rodent models have been used extensively for surgical research, their use is limited in microsurgical tissue transfer due to their small size and the small size of their vessels and nerves. Also, fundamental anatomic differences may make rodent surgical models hard to extrapolate to humans. In this report, the authors present a rabbit model for studying free tissue transfer and nerve regeneration using the innervated free gracilis muscle flap. In providing this report, the authors are hopeful that this model could become a standard investigative method for future investigators to employ in other translational endeavors. The authors have completed 12 innervated gracilis muscle transfers with 2 surgical site infections requiring antibiotic treatment and postoperative wound care. There were no complications related to flap-viability in the study over an average follow-up of 9 months. The return of muscle function with nerve coaptation is seen initially around 12 weeks and complete return of function occurs by 20 weeks. Rabbits are comparatively small, easily available, easy to handle, and cost-effective experimental models. Use of the innervated gracilis muscle free flap in rabbits can provide an excellent and economic model for free tissue transfer and reinnervation studies.
Split-thickness skin grafting is the gold standard for treatment of major skin loss. This techniq... more Split-thickness skin grafting is the gold standard for treatment of major skin loss. This technique is limited by donor-site availability in large burn injuries. With micrografting, a technique where split-thickness skin graft is minced into 0.8 × 0.8-mm pieces, the authors have demonstrated an expansion ratio of 1:100 and healing comparable to that achieved with split-thickness skin grafting. In this study, the authors explore the regenerative potential of a skin graft by cutting split-thickness skin grafts to pixel size (0.3 × 0.3 mm) grafts. Wound healing was studied in full-thickness wounds in a porcine model by creating an incubator-like microenvironment using polyurethane wound chambers. Multiple wound healing parameters were used to study the outcome of pixel grafting and compare it to micrografting and nontransplanted wounds. The authors' results show that 0.3 × 0.3-mm pixel grafts remain viable and contribute to skin regeneration. The pixel graft-transplanted wounds demonstrated a faster reepithelialization rate, decreased wound contraction, and increased mechanical stability compared with nontransplanted wounds. The reepithelialization rates of the wounds were significantly increased with pixel grafting at day 6 after wounding compared with micrografting. Among the other wound healing parameters, there were no significant differences between wounds transplanted with pixel grafts and micrografts. Pixel grafting technique would address the most commonly encountered limitations of the split-thickness skin graft with the possibility of an even larger expansion ratio than micrografting. This technique is simple and fast and can be conducted in the operating room or in the clinic.
Porcine wounds closely mimic human wounds and are often used experimentally in burn studies. Mult... more Porcine wounds closely mimic human wounds and are often used experimentally in burn studies. Multiple burn devices have been reported but they rarely described precise amount of heat transfer and the burn devices generally have low and varying heat capacity resulting in significant and varying temperature drop. The authors developed a customized aluminum burn device with cork insulation and high heat capacity. A thermistor probe was embedded in the device to accurately measure the temperature of the aluminum. The burn injury was inflicted by preheating the burn device to 100°C and pressing on the dorsum of pig skin for different time points ranging from 5 to 30s using standardized force of 10N on the device. With the knowledge of the heat capacity of the aluminum block and the temperature drop, the amount of heat transferred can be calculated. The temperature drop was 0°C, 1°C, 2°C, 3°C and 5°C for a wound-device contact time of 5, 10, 15, 20 and 30s, respectively. The depths of injury at 72h after burn were 0.46mm, 0.82mm, 1.21mm, 1.61mm and 1.91mm at 5, 10, 15, 20 and 30s respectively. 3.1mm represented a full thickness burn. The depth of the burn wounds significantly correlated with the heat transferred per cm(2) (correlation coefficient=0.96, p-value=0.03). The authors describe a simple, standardized and reproducible animal burn model using a customized burn device. The high heat capacity ensures minimal temperature drop which minimizes the variability of heat transferred with a large temperature drop. The correlation between the heat transfer and the depth of injury can facilitate standardization of burn depths in future studies.
Plastic and Reconstructive Surgery - Global Open, 2016
With rising cost of healthcare, there is an urgent need for developing effective and economical s... more With rising cost of healthcare, there is an urgent need for developing effective and economical streamlined care. In clinical situations with limited data or conflicting evidence-based data, there is significant institutional and individual practice variation. Quality improvement with the use of Standardized Clinical Assessment and Management Plans (SCAMPs) might be beneficial in such scenarios. The SCAMPs method has never before been reported to be utilized in plastic surgery. The topic of immediate breast reconstruction was identified as a possible SCAMPs project. The initial stages of SCAMPs development, including planning and implementation, were entered. The SCAMP Champion, along with the SCAMPs support team, developed targeted data statements. The SCAMP was then written and a decision-tree algorithm was built. Buy-in was obtained from the Division of Plastic Surgery and a SCAMPs data form was generated to collect data. Decisions pertaining to "immediate implant-based brea...
Plastic and reconstructive surgery. Global open, 2015
With rising cost of healthcare, there is an urgent need for developing effective and economical s... more With rising cost of healthcare, there is an urgent need for developing effective and economical streamlined care. In clinical situations with limited data or conflicting evidence-based data, there is significant institutional and individual practice variation. Quality improvement with the use of Standardized Clinical Assessment and Management Plans (SCAMPs) might be beneficial in such scenarios. The SCAMPs method has never before been reported to be utilized in plastic surgery. The topic of immediate breast reconstruction was identified as a possible SCAMPs project. The initial stages of SCAMPs development, including planning and implementation, were entered. The SCAMP Champion, along with the SCAMPs support team, developed targeted data statements. The SCAMP was then written and a decision-tree algorithm was built. Buy-in was obtained from the Division of Plastic Surgery and a SCAMPs data form was generated to collect data. Decisions pertaining to "immediate implant-based brea...
Plastic and Reconstructive Surgery - Global Open, 2015
Rhinoplasty in middle-aged and elderly patients comes with its own set of challenges. There is re... more Rhinoplasty in middle-aged and elderly patients comes with its own set of challenges. There is relative lengthening of the nose with drooping of the nasal tip. With aging, the skin loses its elasticity, and the combination of nasal skeletal reduction along with overlying inelastic skin provides a setup for skin redundancy and poor postoperative outcome. We describe a surgical technique involving lenticular skin excision as a part of rhinoplasty in 12 patients older than 50 years to improve the aesthetic outcome. Skin width up to 1.6 cm was excised. Included is a literature review of skin excision in rhinoplasty. In elderly patients with thin, inelastic skin and long nose with a drooping tip, a reduction rhinoplasty technique might result in skin redundancy. Lenticular skin excision along the radix of the nose in these 12 patients improved the aesthetic outcome by decreasing the redundancy and preventing nasal tip ptosis. The wound from the skin resection healed in all the patients with minimal scar, and no complication was noted after at least 1 year of follow-up for each patient.
Palatal fistula is a known complication of cleft lip-cleft palate repair. Fistulas anterior to th... more Palatal fistula is a known complication of cleft lip-cleft palate repair. Fistulas anterior to the incisive foramen can be particularly difficult to repair because of the lack of available tissue. Adjacent tissue has inherent limitations, and multiple free-flap techniques have been described; however, there remains no single solution for this difficult problem. The authors present an alternative strategy of replacing "like with like" by using an osteocutaneous free tissue transfer of the second toe for anterior oronasal fistulas. Use of the osteocutaneous second-toe free flap provides skin lining to both the oral side and the nasal side to close oronasal fistulas. It also bridges the alveolar gap with vascularized bone. This flap can be considered as an elegant alternative for anterior oronasal fistulas.
Abdominoplasty is being increasingly performed as an outpatient procedure. The role of tumescent ... more Abdominoplasty is being increasingly performed as an outpatient procedure. The role of tumescent technique in decreasing postoperative pain and hospital stay has not been extensively studied. We reviewed 65 consecutive patients who underwent tumescent abdominoplasty over 20 months by a single surgeon. All the patients were followed up for at least 1 year. The outcomes were evaluated in terms of systemic complications such as deep vein thrombosis and pulmonary embolism and local complications such as seroma, wound infection, and skin necrosis. Of the 65 patient records analyzed, 61 were of females and 4 of males. Average age for the patient population was 45.2 years. Mean follow-up was at least 1 year for all the patients. Ninety-five percent of patients could be discharged the same day with tumescent abdominoplasty, whereas 71% of the patients who underwent concurrent procedures with abdominoplasty were also able to go home the same day. All the patients reported excellent postopera...
The etiology, clinical impact, natural history and best therapy of unilateral diaphragm paralysis... more The etiology, clinical impact, natural history and best therapy of unilateral diaphragm paralysis (UDP) are incompletely understood. This condition is not amenable to pacing, which requires an intact phrenic nerve. Clinical records of patients with UDP referred to our diaphragm center were reviewed. Thirty-six patients (28 male, 8 female) aged 1 month to 78 years (mean 47.8 years) with UDP evaluated from 1983 to February 2007 were reviewed. Etiology was postsurgical in 13 (36%), tumor (with surgery or radiation therapy) in 7 (19%), idiopathic in 6 (17%), trauma (motor vehicle accident or head injury) in 5 (14%), polio in 3 (8%), and viral in 2 (6%) patients. 28 patients (78%) were symptomatic; 8 (22%) carried a diagnosis of coexisting chronic obstructive pulmonary disease. Mean duration of paralysis was 57.9 months (range up to 261 months). The left diaphragm was involved in 23 cases (64%) and the right in 13 (36%). Mean forced expiratory volume (FEV1) was 1 915 mL (61.3% of predict...
Immediate reconstruction of perineal defects secondary to abdominoperineal resection (APR) or pel... more Immediate reconstruction of perineal defects secondary to abdominoperineal resection (APR) or pelvic exenteration with pedicled flaps decreases post-operative wound complications when compared with direct closure in high-risk patients. While prior authors have been proponents of abdominal-based flaps, here we evaluate the role for thigh-based flaps founded on acceptable outcomes and low morbidity. Consecutive patients referred to a single surgeon between January 2012 and August 2015 who underwent perineal reconstruction with a pedicled gracilis flap were identified. Patients were evaluated for routine pre-operative variables and outcome data analyzed, including time to healing and abdominal and perineal complications. Forty patients were included in the study, with a mean follow-up period of 2 years. There was no 30-day mortality and 37 patients (92.5%) were alive at the last follow-up. Five patients (12.5%) experienced donor-site complications while 16 patients (40%) had recipient-site complications, including hematoma, seroma, or dehiscence. Minor complications were seen in 10 (25%) patients while 7 (17.5%) patients had major complications. Obesity (OR 7.5, p=0.01), and active smoking status (OR 9.3, p=0.01) were significantly associated with minor complications; while a history of neo-adjuvant chemoradiation (OR 21.4, p=0.04) was a significant risk factor for any complication. The overall complication rate with this technique is comparable to the more commonly used VRAM flap but the potential for, and severity of, donor site complications is reduced with this technique. As such, gracilis flaps may be considered an acceptable alternative to abdominal flaps for selected perineal wounds.
Wound healing is traditionally divided into inflammation, proliferation and remodelling phases. S... more Wound healing is traditionally divided into inflammation, proliferation and remodelling phases. Several inflammatory mediators and cells regulate the inflammation phase. The specific roles for different mediators have not been clearly defined. The effects of inflammation phase modulation on wound healing were evaluated in this study. Rat full-thickness wounds were divided into different experimental groups: a) sterile hyper-inflammatory wounds/endotoxin (topical endotoxin), b) sterile hypo-inflammatory/inhibitor group (cocktail of topical COX-1 plus COX-2 plus lipoxygenase inhibitors) c) control groups: topical saline or DMSO. After full-thickness wound creation, custom-made titanium chambers enclosed the wound, creating an isolated well-controlled environment. Wound healing was followed over time; tissue biopsies and wound fluid samples were collected on days 1, 4 and 8 postoperatively.The validity of the inflammation model was confirmed by increased IL-1a expression, increased CD45+ leukocytes recruitment in the hyper-inflamed group as compared to the inhibitor and control groups. The re-epithelialization percentage was significantly increased in the endotoxin group as compared to the inhibitor group on Day 4 (60.75 vs. 22.05, p-value <0.05) and both the inhibitor and the control group on Day 8 (Control Group - 63.2%, Inhibitor Group - 28.9%, Endotoxin Group - 84.2%,p-value <0.05) . Also, the macroscopic wound closure was increased in the endotoxin group as compared to the inhibitor group and control group both on Day 4 (Control Group - 69.9%, Inhibitor Group - 62.9%, Endotoxin Group - 81.9%, p-value <0.05) and on Day 8 (Control Group - 68.5%, Inhibitor Group - 69.1%, Endotoxin Group - 83.7%, p-value <0.05). Endotoxin-induced sterile inflammation up regulates IL-1a expression and CD45+ leukocyte recruitment and results in faster rate of wound re-epithelialization and wound closure in full-thickness rodent wounds. Conversely, the wound re-epithelialization and wound closure can be significantly delayed on treatment with a combination of cyclooxygenase and lipoxygenase inhibitors. This article is protected by copyright. All rights reserved.
"Medical tourism&amp... more "Medical tourism" has gained popularity over the past few decades. This is particularly common with patients seeking elective cosmetic surgery in the developing world. However, the risk of severe and unusual infectious complications appears to be higher than for patients undergoing similar procedures in the United States. The authors describe their experience with atypical mycobacterial infections in cosmetic surgical patients returning to the United States postoperatively. A review of patient medical records presenting with infectious complications after cosmetic surgery between January 2010 and July 2015 was performed. Patients presenting with mycobacterial infections following cosmetic surgery were reviewed in detail. An extensive literature review was performed for rapid-growing mycobacteria (RGM) related to cosmetic procedures. Between January 2010 and July 2015, three patients presented to our institution with culture-proven Mycobacterium abscessus at the sites of recent cosmetic surgery. All had surgery performed in the developing world. The mean age of these patients was 36 years (range, 29-44 years). There was a delay of up to 16 weeks between the initial presentation and correct diagnosis. All patients were treated with surgical drainage and combination antibiotics with complete resolution. We present series of patients with mycobacterial infections after cosmetic surgery in the developing world. This may be related to the endemic nature of these bacteria and/or inadequate sterilization or sterile technique. Due to low domestic incidence of these infections, diagnosis may be difficult and/or delayed. Consulting physicians should have a low threshold to consider atypical etiologies in such scenarios. 5 Therapeutic.
Although rodent models have been used extensively for surgical research, their use is limited in ... more Although rodent models have been used extensively for surgical research, their use is limited in microsurgical tissue transfer due to their small size and the small size of their vessels and nerves. Also, fundamental anatomic differences may make rodent surgical models hard to extrapolate to humans. In this report, the authors present a rabbit model for studying free tissue transfer and nerve regeneration using the innervated free gracilis muscle flap. In providing this report, the authors are hopeful that this model could become a standard investigative method for future investigators to employ in other translational endeavors. The authors have completed 12 innervated gracilis muscle transfers with 2 surgical site infections requiring antibiotic treatment and postoperative wound care. There were no complications related to flap-viability in the study over an average follow-up of 9 months. The return of muscle function with nerve coaptation is seen initially around 12 weeks and complete return of function occurs by 20 weeks. Rabbits are comparatively small, easily available, easy to handle, and cost-effective experimental models. Use of the innervated gracilis muscle free flap in rabbits can provide an excellent and economic model for free tissue transfer and reinnervation studies.
Split-thickness skin grafting is the gold standard for treatment of major skin loss. This techniq... more Split-thickness skin grafting is the gold standard for treatment of major skin loss. This technique is limited by donor-site availability in large burn injuries. With micrografting, a technique where split-thickness skin graft is minced into 0.8 × 0.8-mm pieces, the authors have demonstrated an expansion ratio of 1:100 and healing comparable to that achieved with split-thickness skin grafting. In this study, the authors explore the regenerative potential of a skin graft by cutting split-thickness skin grafts to pixel size (0.3 × 0.3 mm) grafts. Wound healing was studied in full-thickness wounds in a porcine model by creating an incubator-like microenvironment using polyurethane wound chambers. Multiple wound healing parameters were used to study the outcome of pixel grafting and compare it to micrografting and nontransplanted wounds. The authors' results show that 0.3 × 0.3-mm pixel grafts remain viable and contribute to skin regeneration. The pixel graft-transplanted wounds demonstrated a faster reepithelialization rate, decreased wound contraction, and increased mechanical stability compared with nontransplanted wounds. The reepithelialization rates of the wounds were significantly increased with pixel grafting at day 6 after wounding compared with micrografting. Among the other wound healing parameters, there were no significant differences between wounds transplanted with pixel grafts and micrografts. Pixel grafting technique would address the most commonly encountered limitations of the split-thickness skin graft with the possibility of an even larger expansion ratio than micrografting. This technique is simple and fast and can be conducted in the operating room or in the clinic.
Porcine wounds closely mimic human wounds and are often used experimentally in burn studies. Mult... more Porcine wounds closely mimic human wounds and are often used experimentally in burn studies. Multiple burn devices have been reported but they rarely described precise amount of heat transfer and the burn devices generally have low and varying heat capacity resulting in significant and varying temperature drop. The authors developed a customized aluminum burn device with cork insulation and high heat capacity. A thermistor probe was embedded in the device to accurately measure the temperature of the aluminum. The burn injury was inflicted by preheating the burn device to 100°C and pressing on the dorsum of pig skin for different time points ranging from 5 to 30s using standardized force of 10N on the device. With the knowledge of the heat capacity of the aluminum block and the temperature drop, the amount of heat transferred can be calculated. The temperature drop was 0°C, 1°C, 2°C, 3°C and 5°C for a wound-device contact time of 5, 10, 15, 20 and 30s, respectively. The depths of injury at 72h after burn were 0.46mm, 0.82mm, 1.21mm, 1.61mm and 1.91mm at 5, 10, 15, 20 and 30s respectively. 3.1mm represented a full thickness burn. The depth of the burn wounds significantly correlated with the heat transferred per cm(2) (correlation coefficient=0.96, p-value=0.03). The authors describe a simple, standardized and reproducible animal burn model using a customized burn device. The high heat capacity ensures minimal temperature drop which minimizes the variability of heat transferred with a large temperature drop. The correlation between the heat transfer and the depth of injury can facilitate standardization of burn depths in future studies.
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Papers by Mansher Singh