Microsurgical free tissue transfer may be the only reconstructive option for lower extremity limb salvage. However, the functional and aesthetic results following free tissue transfer after initial ...salvage may be suboptimal, thus requiring secondary surgeries to facilitate definitive wound healing and/or refinement.
A multi-institutional retrospective cohort study was performed including patients who underwent lower extremity free tissue transfer from January 2002 to December 2020. Our primary outcome variable was the presence of secondary surgery after free tissue transfer for lower extremity reconstruction. Independent variables (wound etiology, flap, donor type, recipient, co-morbidities, etc.) were collected. Secondary surgery was categorized as (1) procedures for definitive wound closure and (2) refinement procedures. Multivariable logistic regression was performed to determine which variables were independently associated with the outcome.
Four-hundred-and-twenty free tissue transfers for lower extremity reconstruction were identified. Secondary surgery was performed in over half (57%) of the patients. Presence of diabetes (OR: 2.0, p: 0.01, 95% CI: 1.2-3.5) and use of a latissimus dorsi donor (OR: 2.4, p: 0.037, 95% CI: 1.1-5.4) were predictors of wound closure procedures. Fasciocutaneous (OR 3.6, p: <0.001, 95% CI 1.8-7.2) and myocutaneous (OR: 3.0, p=0.005, 95% CI 1.5-9.9) flaps were predictors of refinement procedures when compared to muscle-only flaps with skin grafts.
The majority of lower extremity free tissue reconstructions required secondary procedures to provide definitive wound closure and/or refinement. Overall, this study provides predictors of secondary surgery that will help formulate patients' expectations of lower extremity limb salvage.
Lower extremity free flap failure rates are higher than in other areas of the body. While prior studies assessed the effect of intraoperative technical variables, these generally investigated ...individual variables and did not examine relationships between the many individual technical decisions made during free tissue reconstruction. Our purpose was to investigate the effect of variation in intraoperative microsurgical techniques on flap outcomes in a diverse cohort of patients requiring lower extremity free flap coverage.
Consecutive patients undergoing free flap reconstruction of the lower extremity at two level 1 trauma centers from January 2002 to January 2020 were identified using Current Procedural Terminology codes, followed by a review of medical records. Information regarding demographics and comorbidities, indications, intraoperative technical details, and complications was collected. Outcomes of interest included an unplanned return to the operating room, arterial thrombosis, venous thrombosis, partial flap failure, and total flap failure. Bivariate analysis was performed.
In total, 410 patients underwent 420 free tissue transfers. The median follow-up time was 17 months (interquartile ranges: 8.0-37). Total flap failure occurred in 4.9% (
= 20), partial flap failure in 5.9% (
= 24), and unplanned reoperation in 9.0% (
= 37), with arterial thrombosis in 3.2% (
= 13) and venous thrombosis in 5.4% (
= 22). Overall complications were significantly associated with recipient artery choice, with arteries other than PT and AT/DP having a higher rate (
= 0.033), and with arterial revisions (
= 0.010). Total flap failure was also associated with revision of the arterial anastomosis (
= 0.035), and partial flap failure was associated with recipient artery choice (
= 0.032).
Many interoperative options and techniques are available when performing microvascular lower extremity reconstruction that leads to equally high success rates. However, the use of arterial inflow outside of the posterior tibial and anterior tibial arteries leads to a higher overall complication rate and partial flap failure rate. Intraoperative revision of the arterial anastomosis portends poorly for ultimate flap survival.
A pentapeptide macrocyclic ligand, KYCAR (lysyl-tyrosyl-cystyl-alanyl-arginine), has been designed as a potential chelating ligand for SPECT imaging and therapeutic
in vivo
agents. This study shows ...the synthesis and characterization of KYCAR complexes containing nonradioactive rhenium,
99m
Tc, or
188
Re. The metal complexes were also biologically evaluated to determine
in vivo
distribution in healthy mice. The overall goals of this project were (1) to synthesize the Tc/Re pentapeptide complexes, (2) to identify spectroscopic methods for characterization of syn versus anti rhenium peptide complexes, (3) to analyze the ex vivo stability, and (4) to assess the biological properties of the
99m
TcTcO-KYCAR and
188
ReReO-KYCAR complexes
in vivo
. Details on these efforts are provided below.
A pentapeptide macrocyclic ligand, KYCAR (lysyl-tyrosyl-cystyl-alanyl-arginine), has been designed as a potential chelating ligand for SPECT imaging and therapeutic in vivo agents. This study shows ...the synthesis and characterization of KYCAR complexes containing nonradioactive rhenium, 99mTc, or 188Re. The metal complexes were also biologically evaluated to determine in vivo distribution in healthy mice. The overall goals of this project were (1) to synthesize the Tc/Re pentapeptide complexes, (2) to identify spectroscopic methods for characterization of syn versus anti rhenium peptide complexes, (3) to analyze the ex vivo stability, and (4) to assess the biological properties of the 99mTcTcO-KYCAR and 188ReReO-KYCAR complexes in vivo. Details on these efforts are provided below.
NatRe/99mTc/188ReO-KYCAR complexes were synthesized, and macroscopic species were characterized via HPLC, IR, NMR, and CD. These characterization data were compared to the crystallographic data of ReO-KYC to assist in the assignment of diastereomers and to aid in the determination of the structure of the complex.
The radiometal complexes were synthesized with high purity (>95%). HPLC, IR, NMR and CD data on the macroscopic natReO-KYCAR complexes confirm the successful complexation as well as the presence of two diastereomers in syn and anticonformations. Tracer level complexes show favorable stabilities ex vivo for 2+ h.
Macroscopic metal complexes form diastereomers with the KYCAR ligand; however, this phenomenon is not readily observed on the tracer level due to the rapid interconversion. It was determined through pKa measurements that the macroscopic natReO-KYCAR complex is 0 at physiological pH. The 99mTcTcO-KYCAR is stable in vitro while the 188ReReO-KYCAR shows 50% decomposition in PBS and serum. Biologically, the tracer level complexes clear through the hepatobiliary pathway. Some decomposition of both tracers is evident by uptake in the thyroid and stomach.
The reaction of aryl alkynes with dilute methylene chloride solutions of quaternary ammonium bromide and 20% trifluoroacetic acid produces primarily the syn Markovnikov adducts of hydrogen bromide. ...At moderate concentrations of the bromide, the principal product is the Markovnikov anti adduct. At high concentrations of bromide, the anti-Markovnikov anti addition product predominates.
Purpose: To evaluate the feasibility of tacrolimus 0.03% dermatological ointment (Protopic) in the treatment of intractable allergic conjunctivitis. Methods: Twenty patients (mean age 10.8 years, ...range 6-26) with intractable allergic conjunctivitis were enrolled in an open-label study. Tacrolimus 0.03% ointment was applied into the conjunctival sac of both eyes twice daily for 8 weeks, followed by a 2-week washout period. Other ocular medications were discontinued. Conjunctivitis severity was recorded with a composite subjective/objective score (chemosis, tarsal papillary size, corneal staining, tearing, itching, and photophobia) at baseline, week 8, and after washout. Tacrolimus blood levels were measured at 2 weeks. Results: Statistically significant improvement in all categories of the conjunctivitis score was observed between baseline and the week 8 examination (p < 0.001). Adverse events were limited to local burning in one patient who discontinued treatment. Blood tacrolimus levels were mostly undetectable. Conclusions: Application of tacrolimus 0.03% dermatological ointment into the conjunctival sac appears to be effective, well tolerated, and safe in the treatment of allergic conjunctivitis refractory to traditional treatment.
Objectives: Inbred mouse strains differ in the pharmacology mediating sugar and fat intake and conditioned flavor preferences (CFP). C57BL/6, BALB/c and SWR inbred mice are differentially sensitive ...to dopamine (DA) D1, opioid and muscarinic receptor antagonism of sucrose, saccharin or fat intake, and to DA, opioid, muscarinic and N-methyl-D-aspartate (NMDA) receptor antagonism of acquisition of sucrose-CFP. DA D1, opioid and NMDA receptor antagonists differentially alter fat (Intralipid)-CFP in BALB/c and SWR mice. The present study examined whether naltrexone, SCH23390 or MK-801 altered acquisition and expression of Intralipid-CFP in C57BL/6 mice.
Methods: In acquisition, groups of male food-restricted C57BL/6 mice received vehicle, naltrexone (1, 5 mg/kg), SCH23390 (50, 200 nmol/kg) or MK-801 (100, 200 μg/kg) before 10 training sessions in which mice alternately consumed two novel-flavored 5% (CS+) and 0.5% (CS-) Intralipid solutions. Six two-bottle CS choice tests followed with both flavors mixed in 0.5% Intralipid without injections. In expression, C57BL/6 mice underwent the 10 training sessions without injections followed by two-bottle CS choice tests 30 min following vehicle, naltrexone (1, 5 mg/kg), SCH23390 (200, 800 nmol/kg) or MK-801 (100, 200 μg/kg).
Results: Fat-CFP acquisition in C57BL/6 mice was significantly though marginally reduced following naltrexone, SCH23390 and MK-801. Fat-CFP expression was similarly reduced by naltrexone, SCH23390 and MK-801 in C57BL/6 mice. Discussion: C57BL/6 mice were more sensitive to DA D1, opioid and NMDA antagonists in the expression of fat-CFP relative to sugar-CFP, but were less sensitive to DA D1 and NMDA antagonists in the acquisition of fat-CFP relative to sugar-CFP.
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