Preoperative Computed Tomography Angiography for Evaluation of Feasibility of Free Flaps in Difficult Reconstruction of Head and Neck

Clinical application of digital technology in the use of anterolateral thigh lobulated perforator flaps to repair complex soft tissue defects of the limbs

Background

It is challenging to repair wide or irregular defects with traditional skin flaps, and anterolateral thigh (ALT) lobulated perforator flaps are an ideal choice for such defects. However, there are many variations in perforators, so good preoperative planning is very important. This study attempted to explore the feasibility and clinical effect of digital technology in the use of ALT lobulated perforator flaps for repairing complex soft tissue defects in limbs.

Methods

Computed tomography angiography (CTA) was performed on 28 patients with complex soft tissue defects of the limbs, and the CTA data were imported into Mimics 20.0 software in DICOM format. According to the perforation condition of the lateral circumflex femoral artery and the size of the limb defect, one thigh that had two or more perforators from the same source vessel was selected for 3D reconstruction of the ALT lobulated perforator flap model. Mimics 20.0 software was used to visualize the vascular anatomy, virtual design and harvest of the flap before surgery. The intraoperative design and excision of the ALT lobulated perforator flap were guided by the preoperative digital design, and the actual anatomical observations and measurements were recorded.

Results

Digital reconstruction was successfully performed in all patients before surgery; this reconstruction dynamically displayed the anatomical structure of the flap vasculature and accurately guided the design and harvest of the flap during surgery. The parameters of the harvested flaps were consistent with the preoperative parameters. Postoperative complications occurred in 7 patients, but all flaps survived uneventfully. All of the donor sites were closed directly. All patients were followed up for 13-27 months (mean, 19.75 months). The color and texture of each flap were satisfactory and each donor site exhibited a linear scar.

Conclusions

Digital technology can effectively and precisely assist in the design and harvest of ALT lobulated perforator flaps, provide an effective approach for individualized evaluation and flap design and reduce the risk and difficulty of surgery.

Preimaging and Postimaging of Graft and Flap in Head and Neck Reconstruction

Head and neck reconstructive surgical techniques are complex; now the microvascular free tissue transfer is the most frequently used. The postreconstruction imaging interpretation is challenging due to the altered anatomy and flap variability. We aim to improve radiologists' knowledge with diverse methods of flap reconstruction for an accurate appreciation of their expected cross-sectional imaging appearance and early detection of tumor recurrence and other complication.

Three-dimensional CT angiography for surgical planning in congenital hand malformations: a case series presentation

Between January 2000 and December 2019, three-dimensional computer tomographic (CT) angiography was used in a total of 140 hands (116 patients, mean age 6.8 years) with congenital hand malformation to assess the vascular and bony structures. Analysis showed overall satisfactory three-dimensional CT images for operative planning, including detailed abnormal vascular patterns and bony malformations. Among the 116 patients, six patients with typical findings of a few malformations are reported in detail. Pitfalls in interpretation of the images and the use of three-dimensional CT angiography in surgical planning are discussed. We conclude that three-dimensional CT angiography is useful for preoperative planning of complex congenital hand malformations.Level of evidence: IV.

Investigation of Free-Flap Transfer Reconstruction in Elderly Patients and Oral Intake Function

The authors retrospectively examined 39 patients with head and neck reconstruction using a free-flap transfer with microsurgery in elderly patients aged over 80 years in our hospital. They investigated postoperative local complications, postoperative systemic complications, day of ambulation, the presence of delirium, the postoperative oral intake ratio, and the reconstructive method in mandibular reconstruction patients. There were 12 postoperative local complications. And postoperative systemic complications were detected in 19 patients; however, 17 of these were respiratory disorders due to pneumonia. There were 17 patients with postoperative delirium. Oral intake was resumed after an average of 14.9 days. Of these, 34 patients were eventually able to eat some kind of food. The incidence of local complications in elderly free-flap reconstruction patients was similar to that in young people. However, the rate of systemic complications was much higher in elderly patients. The authors suggest that free-flap reconstruction can be performed relatively safely in elderly people when a detailed preoperative surgical plan.

Heparin-Eluting Electrospun Nanofiber Yarns for Antithrombotic Vascular Sutures

The surgical connection of blood vessels, anastomosis, is a critical procedure in many reparative, transplantation, and reconstructive surgical procedures. However, effective restoration of circulation is complicated by pathological clotting (thrombosis) or progressive occlusion due to excess cell proliferation that often leads to additional surgeries and increases morbidity and mortality risk for patients. Pharmaceutical agents have been tested to prevent these complications, but many have unacceptable systemic side effects. Therefore, an alternative approach to deliver these drugs at the site of injury in a controlled manner is necessary. The objective of this study was to develop electrospun nanofibers composed of polyester poly(lactide- co-glycolide) (PLGA), poly(ethylene oxide) (PEO), and positively charged copolymer, poly(lactide- co-glycolide)- graft-polyethylenimine (PgP) for electrostatic binding and release of heparin for application as an antithrombotic microvascular suture. PgP was synthesized with different coupling ratios between PLGA and branched polyethylenimine (bPEI) to obtain PgP₁ (∼1 PLGA grafted to 1 bPEI) and PgP_3.7 (∼3.7 PLGA grafted to 1 bPEI). Nanofiber yarns (PLGA/PEO/PgP₁ and PLGA/PEO/PgP_3.7) were fabricated by electrospinning. Heparin immobilization on the positively charged nanofiber yarns was visualized using fluorescein-conjugated heparin (F-Hep), and the amount of immobilized F-Hep was higher on both PLGA/PEO/PgP_3.7 and PLGA/PEO/PgP₁ than yarns without PgP (PLGA/PEO). We also found that F-Hep was released from both PgP-containing yarns in a sustained manner over 20 days, while over 60% of F-Hep was released within 4 h from PLGA/PEO. Finally, we observed that heparin-eluting nanofiber yarns with both PgP₁ and PgP_3.7 showed significantly longer clotting times than nanofiber yarns without PgP. The clotting time of PLGA/PEO/PgP_3.7 was not significantly different than that of free heparin (0.5 μg/mL). These results show that heparin-eluting electrospun nanofiber yarns may offer a basis for the development of microvascular sutures with anticoagulant activity.

Third Repeat Microvascular Reconstruction in Head and Neck Cancer Patients Aged 65 Years and Older: A Longitudinal and Sequential Analysis

Performing a sequential third free flap for reconstruction of a head and neck defect after cancer resection can be challenging, and the problem is further compounded in elderly patients. The outcomes in this clinical scenario are currently unknown and this study aims to compare the results in elderly patients with younger patients in a high-volume microsurgical unit. A retrospective review of 126 consecutive patients who had undergone three sequential free flap reconstructions after head and neck cancer was performed. The patients were divided into two groups – older or younger than 65 years old (n = 105 and n = 21, respectively). Patient demographics, intraoperative and postoperative outcomes were noted and analyzed. The overall flap success in this patient cohort was 94.4% (7 flap losses in 126 patients). Cardiovascular complications were significantly more common in the older group (19% vs. 1.9%, p = 0.001). Delirium occurred more frequently in the older group compared with the younger group (23.8% vs. 6.7%, p = 0.023). There were no significant differences regarding surgical complications. With adequate planning, a sequential third free flap can be performed safely and successfully in patients who are more than 65 years of age. Particular attention to the perioperative morbidity in elderly patients is crucial for successful outcomes.