The prognostic role of extended preoperative hypercoagulability work-up in high-risk microsurgical free flaps: a single-center retrospective case series of patients with heterozygotic factor V Leiden thrombophilia.

INTRODUCTION: Hypercoagulability is associated with an increased risk of microvascular complications and free flap failures. The authors present their experience and approach to diagnosing and treating patients with heterozygotic factor V Leiden (hFVL) thrombophilia undergoing free flap reconstruction. METHODS: Between November 2009 and June 2018, 23 free flap surgeries were performed in 15 hypercoagulable patients with hFVL. According to the timing of perioperative hypercoagulability work-up, they were grouped into flaps with established diagnoses prior to surgery (Group A) versus flaps with unknown diagnoses prior to surgery (Group B). Baseline characteristics and perioperative complications were compared between both groups, including revision surgeries due to microvascular thromboses, acute bleedings, hematomas, flap necroses, and reconstructive failures. RESULTS: HFVL mutations had been confirmed preoperatively in 14 free flap surgeries (61%, Group A), whereas in 9 free flap surgeries (39%, Group B), mutations were only diagnosed postoperatively after the occurrence of microvascular thromboses had warranted extended hypercoagulability work-up. The overall rate of intraoperative flap thromboses was 9% (n = 2), whereas the overall rate of postoperative flap thromboses was 43% (n = 10). The corresponding salvage rates were 100% (n = 2/2) for intraoperative and 40% (n = 4/10) for postoperative pedicle thromboses. A total of five free flaps were lost (22%). Upon comparison, flaps with an unconfirmed diagnosis prior to surgery were at ten times higher risk for developing total necroses (flaps lost in Group B = 4/9 versus Group A = 1/14; OR: 10.4; 95% CI 1.0, 134.7; p = 0.03). CONCLUSION: Meticulous preoperative work-up of patients with any history of hypercoagulability can help reduce free flap loss rates, thus improving surgical outcomes and increasing patient safety.

Microsurgical reconstruction of extensive lower extremity defects with the conjoined parascapular and latissimus dorsi free flap.

BACKGROUND: Extensive lower extremity soft-tissue defects pose a reconstructive challenge. We present our experience with the conjoined parascapular and latissimus dorsi (CPLD) free flap. METHODS: From October 2008 to October 2017, 69 patients (14 female, 55 male) with a mean age of 50 years (range: 16-79 years) underwent reconstruction of lower extremity defects with the CPLD free flap. Mean defect size was 24 × 36 cm (range: 14 × 20 to 45 × 80 cm). RESULTS: Mean latissimus dorsi (LD) flap size was 19 × 28 cm (range: 14 × 20 to 28 × 42 cm) and mean parascapular (PSC) flap size was 8 × 25 cm (range: 5 × 12 to 11 × 33 cm). Six patients (9%) experienced a total of eight microvascular complications: arterial thrombosis (n = 1), venous thrombosis (n = 6), combined arterial and venous thrombosis (n = 1). The re-exploration rate was 13%. Major complications of the donor-site were seen in 9 patients (13%), of the flap in 13 patients (19%), and of both in 6 patients (9%). Fifteen patients experienced partial flap necrosis (22%). Three CPLD and one PSC flap were lost (5%). PSC flap length was a significant predictor of distal flap necrosis (χ2 (1) = 13.2, p = .004, OR = 1.343, 95% CI [1.098-1.642]). PSC flap width was a significant predictor of donor-site revisions (χ2 (1) = 15.9, p = .010, OR = 4.745, 95% CI [1.584-14.213]). Arterio-venous loops (AVLs) tended to increase the risk of microvascular thrombosis (χ2 (1) = 3.7, p = .08, OR = 4.1, 95% CI [0.9-18.7]). CONCLUSIONS: The CPLD free flap is an extremely large and highly reliable flap, allowing one-stage reconstruction of extensive lower extremity defects. It may overcome the need for multiple flaps in selected cases.

Long-Term Outcome after Successful Lower Extremity Free Flap Salvage.

BACKGROUND: Vascular occlusion after free flap surgery has become a rare complication but still poses a major challenge. It necessitates urgent re-exploration, but the logistic challenge to provide sufficient resources for the emergency intervention remains. The aim of this study was to analyze the long-term outcome after successful lower extremity free flap salvage. METHODS: A single-center retrospective study including long-term follow-up was approved by the local ethics committee. From January 1999 to December 2010, a total of 581 free flaps were performed for lower extremity reconstruction. Eighty-six flaps required emergency re-exploration, of which 65 could be salvaged. Fifteen salvaged flaps were excluded from the study because of secondary amputation. Of 50 patients, 29 (6 females and 23 males) were eligible for follow-up. The mean follow-up time was 54.5 ± 32.9 months. Health-related quality of life (Short Form 36 [SF-36]) and scar quality (Vancouver Scar Scale [VSS]) were analyzed. RESULTS: The overall flap survival rate was 94.7% and the total loss rate was 5.3%. The re-exploration rate was 14.8% (86 of 581 flaps). The salvage rate was 75.6% (65 of 86 flaps). Twenty-one free flaps were totally lost (24.4%). Partial flap loss occurred in 12 cases (14.0%); 67.5% of the vascular complications occurred during the first 24 hours, 20.9% between 24 and 72 hours, and 11.6% after more than 72 hours. The mean time from the first signs of impaired flap perfusion to re-exploration was 1.3 ± 0.4 hours, and from free tissue transfer to re-exploration was 16.2 ± 1.9 hours. The overall scar appearance was good with an average VSS score of 4.0 points. The average SF-36 physical component score was 54.4 ± 5.4 and the mental component score was 63.1 ± 10.7. CONCLUSION: Careful monitoring and the opportunity for urgent re-exploration are the key to success for free flaps salvage. Following these principles, an acceptable long-term outcome can be achieved.

Teaching Microsurgical Breast Reconstruction-A Retrospective Cohort Study.

Microsurgical breast reconstruction demands the highest level of expertise in both reconstructive and aesthetic plastic surgery. Implementation of such a complex surgical procedure is generally associated with a learning curve defined by higher complication rates at the beginning. The aim of this study was to present an approach for teaching deep inferior epigastric artery perforator (DIEP) and transverse upper gracilis (TUG) flap breast reconstruction, which can diminish complications and provide satisfying outcomes from the beginning. DIEP and TUG flap procedures for breast reconstruction were either performed by a senior surgeon (>200 DIEP/TUG, "no-training group"), or taught to one of five trainees (>80 breast surgeries; >50 free flaps) in a step-wise approach. The latter were either performed by the senior surgeon, and a trainee was assisting the surgery ("passive training"); by the trainee, and a senior surgeon was supervising ("active training"); or by the trainee without a senior surgeon ("after training"). Surgeries of each group were analyzed regarding OR-time, complications, and refinement procedures. A total of 95 DIEP and 93 TUG flaps were included into this study. Before the first DIEP/TUG flap without supervision, each trainee underwent a mean of 6.8 DIEP and 7.3 TUG training surgeries (p > 0.05). Outcome measures did not reveal any statistically significant differences (passive training/active training/after training/no-training: OR-time (min): DIEP: 331/351/338/304 (p > 0.05); TUG: 229/214/239/217 (p > 0.05); complications (n): DIEP: 6/13/16/11 (p > 0.05); TUG: 6/19/23/11 (p > 0.05); refinement procedures (n): DIEP:71/63/49/44 (p > 0.05); TUG: 65/41/36/56 (p > 0.05)), indicating safe and secure implementation of this step-wise training approach for microsurgical breast reconstruction in both aesthetic and reconstructive measures. Of note, despite being a perforator flap, DIEP flap required no more training than TUG flap, highlighting the importance of flap inset at the recipient site.

Antiseptic therapy with a polylacticacid-acetic acid matrix in burns.

Bacterial colonization and infection are still the major causes of delayed healing and graft rejection following burns and they are furthermore the basis for second and third hit sepsis. Topical treatment is necessary to reduce the incidence of burn wound infection. Silver sulphadiazine (SD-Ag) is a frequently used microbicidal agent. However, this treatment causes adverse reactions and side-effects. Additionally, in recent years multiresistant bacteria, which have not been treated sufficiently, are on the rise. On the basis of experimental data and clinical application of a polylacticacid-acetic acid matrix, we performed this study to establish the effectiveness of the antiseptic therapy with the topical application of a polylacticacid-acetic acid matrix to provide an alternative method for burn treatment, using SD-Ag as a reference. Twenty patients with IIb° or III° burns from the Plastic Surgery and Burns Unit were treated within a matched pair comparative setting. One burned area was treated with SD-Ag, the other corresponding area with the polylacticacid-acetic acid matrix. All patients underwent a necrectomy 4-5 days after the trauma. The excised burned skin was sent to our microbiological laboratory to determine the different bacteria per gram in this tissue. Despite the number of 20 patients, statistical significance was not achieved, there were tendencies to a better antiseptic effectiveness of the polylacticacid-acetic acid matrix. These results suggest that the polylacticacid-acetic acid matrix should be studied in greater depth and could be used as a valid alternative for the topical treatment of burns, as it is equivalent or even more effective than SD-Ag.

Haemodynamically stimulated and in vivo generated axially vascularized soft-tissue free flaps for closure of complex defects: Evaluation in a small animal model.

The arteriovenous (AV) loop model permits the creation of significant volumes of axially vascularized tissue that represents an alternative to conventional free flaps, circumventing their common limitations. However, such AV loop-based flaps have never before been examined in standardized animal models with respect to their suitability for reconstruction of critical bone-exposing defects. In the course of our preliminary studies, we implemented a novel defect model in rats that provides standardized and critical wound conditions and evaluated whether AV loop-generated flaps are suitable for free microsurgical transfer and closure of composite defects. We compared three groups of rodents with similar scapular defects: one received the AV flap, whereas controls were left to heal by secondary intention or with supplementary acellular matrix alone. To create the flaps, AV loops were placed into subcutaneous Teflon chambers filled with acellular matrix and transferred to the thigh region. Flap maturation was evaluated by histological analysis of angiogenesis and cell migration at days 14 and 28 after loop creation. Flap transfer to the scapular region and microsurgical anastomoses were performed after 14 days. Postoperative defect closure and perfusion were continually compared between groups. Within the AV flap chamber, the mean vessel number, cell count and the proportion of proliferating cells increased significantly over time. The novel defect model revealed that stable wound coverage with homogeneous vascular integration was achieved by AV loop-vascularized soft-tissue free flaps compared with controls. In summary, our study indicates for the first time that complex composite defects in rats can successfully be treated with AV loop-based free flaps.

[Functional outcome following high-pressure injection injuries of the hand]. / Funktionelle Ergebnisse nach Hochdruckeinspritzverletzungen der Hand.

Background High-pressure injection injuries are devastating injuries that often lead to an amputation of the primarily affected finger. The available literature mainly focuses on amputation rates, while there is a lack of knowledge regarding functional results. Patients and Methods Between 1998 and 2016, 47 cases of high-pressure injection injuries of the hand were registered in our department. Out of these, data of 26 patients, all men with an average age of 42 (18-62) years, were included in a retrospective follow-up examination after 4 (1-12) years. We recorded DASH scores, pain intensity on visual analogue scales (VAS, 1-10), fingertip-to-palm distance, active range of wrist motion, grip strength, and two-point-discrimination ability (2PD). The statistical analysis was descriptive and was performed by analysis of correlation. Results The average DASH score of these 26 patients was 45 (30-93), pain intensity was 2.5 (0-9) on the VAS, fingertip-to-palm distance was 1 (0-4) cm. Active range of wrist motion was 99 (77-122) % of the contralateral side. Average grip strength was reduced to 67 (0-164) % of the contralateral side. Average 2PD was 9 (2-25) mm. Nineteen out of 26 patients returned to work. An amputation was necessary in 7 out of 26 cases. These patients had more pain and less grip strength. High latency from injury to operative treatment impaired functional outcome, which was statistically significant for DASH (p < 0.05). A trend to poorer outcomes was noted in cases of a more distal lesion and injection of toxic substances, whereas high injection pressure had no negative influence. Conclusion High-pressure injection injuries have serious consequences regarding hand function and frequently cause chronic pain. This affects patients with finger preservation as well as patients requiring an amputation. A further evaluation of prognostic factors requires a metaanalysis of functional parameters. The DASH score seems to be an expedient assessment tool.

Immunosuppressive effect of tryptophan metabolites in composite tissue allotransplantation.

BACKGROUND: Hand transplantations have intensified immunological research into composite tissue allotransplantation to induce tolerance. Pregnancy is a successful, natural model of immunological tolerance. The enzyme indoleamine 2,3-deoxygenase plays an important role by catabolizing the amino acid tryptophan. The resulting metabolites have been shown to be immunosuppressive. The effect of tryptophan metabolites has not been investigated in vascularized organ transplantation before. In this study, the authors applied to composite tissue allotransplantation what nature has developed for pregnancy, and examined the immunosuppressive effect of tryptophan metabolites in a model of hind limb transplantation. METHODS: Thirty-three allogeneic hind limb transplantations in the rat (Lewis --> Brown-Norway) were performed in three groups. Group A (n = 12) received no immunosuppression, group B (n = 13) received tryptophan metabolites (kynurenine and 3-hydroxyanthranilic acid) locally and systemically, and group C (n = 8) served as a control group receiving FK506. The timing of rejection was assessed by clinical observation. RESULTS: Rejection of the allogeneic hind limb occurred on average 6.58 days after transplantation in group A (no immunosuppression) and after 8.15 days in group B (tryptophan metabolites). Rejection was significantly delayed (log-rank test, p < 0.01). No rejection was seen with application of FK506 during the follow-up period of 21 days. CONCLUSIONS: For the first time, tryptophan metabolites have been applied in vascularized composite tissue allotransplantation and showed a significant immunosuppressive effect. These promising first results need further dose-effect and toxicological studies to increase the still limited immunosuppressive effect and define the clinical role these metabolites may play in the future.