Machine Perfusion Deters Ischemia-Related Derangement of a Rodent Free Flap: Development of a Model

INTRODUCTION

Machine perfusion can enable isolated support of composite tissues, such as free flaps. The goal of perfusion in this setting is to preserve tissues prior to transplantation or provide transient support at the wound bed. This study aimed to establish a rodent model of machine perfusion in a fasciocutaneous-free flap to serve as an affordable testbed and determine the potential of the developed support protocol to deter ischemia-related metabolic derangement.

METHODS

Rat epigastric-free flaps were harvested and transferred to a closed circuit that provides circulatory and respiratory support. Whole rat blood was recirculated for 8 h, while adjusting the flow rate to maintain arterial-like perfusion pressures. Blood samples were collected during support. Extracellular tissue lactate and glucose levels were characterized with a microdialysis probe and compared with warm ischemic, cold ischemic, and anastomosed-free flap controls.

RESULTS

Maintenance of physiologic arterial pressures (85-100 mmHg) resulted in average pump flow rates of 360-430 μL/min. Blood-based measurements showed maintained glucose and oxygen consumption throughout machine perfusion. Average normalized lactate to glucose ratio for the perfused flaps was 5-32-fold lower than that for the warm ischemic flap controls during hours 2-8 (P < 0.05).

CONCLUSIONS

We developed a rat model of ex vivo machine perfusion of a fasciocutaneous-free flap with maintained stable flow and tissue metabolic activity for 8 h. This model can be used to assess critical elements of support in this setting as well as explore other novel therapies and technologies to improve free tissue transfer.

Management of the intraoperative loss of microsurgical needles: A literature review and clinical survey

Data on the incidence, management, and consequences of retained microsurgical needles in plastic and reconstructive surgery remains sparse. Research suggests that a mobile C-arm x-ray has a low detection rate for needles of size 8-0 or smaller. By means of a literature review, and survey, we aimed to investigate the current practice employed in the event of the intraoperative loss of a microsurgical needle. A literature review was conducted investigating the incidence, current management strategies, and consequences of retained microsurgical needles. This informed the questions included in a survey investigating management strategies employed in the intra-operative loss of a microsurgical needle. Results from the literature review show an overall low detection rate of microsurgical needles on imaging. Of the forty responders who completed the survey, 80% did not use a mobile C-arm x-ray to locate a missing microsurgical needle. Of the 20% that had done so, x-ray had been unsuccessful in locating the needle in all cases. Portable x-ray has a definite role to play in locating needles of size 7-0 or larger. This study suggests that suture needles of size 8-0 or smaller cannot be reliably detected on x-ray. Regarding management of this event, one should consider the risk of harm to the patient if retained, against the risk of searching for the needle. Based on the results of this work as well as existing published data, we advise against obtaining intra-operative x-rays in the event of a lost needle size 8-0 and above. Appropriate documentation should be completed.

Diversity of the free helical rim flap: A case series tailoring the microsurgical technique to esthetically optimize full-thickness nasal defect reconstructions

INTRODUCTION

The free helical rim (FHR) flap offers like-with-like reconstruction for full-thickness nasal defects. A case series of nasal reconstruction using an FHR flap was presented, detailing surgical steps and refinements, as well as functional and esthetic outcomes.

METHODS AND MATERIALS

This is a retrospective cohort study of composite nasal defect reconstruction with FHR flap from August 2018 to March 2020. Descriptive data were analyzed by SPSS software.

RESULTS

Six cases were recruited, four were unilateral alar defects, one was hemi-nose, and one was ala plus tip. The average size of the defect was 2.5 × 2.8 cm2. Three FHR flaps were designed with retrograde pedicles and three with anterograde pedicles. The facial artery and veins were the recipient vessels in all cases. Vascular grafts were used in all six cases. Descending branch of the lateral circumflex femoral (DLCxF) artery and vein functioned as interposition vascular conduits in five cases. Superficial forearm vein grafts were used in one case. One patient needed flap re-exploration due to venous congestion. One patient had partial flap necrosis due to delayed infection, and one developed delayed wound dehiscence in the irradiated wound. The average follow-up was 18 months.

CONCLUSION

The FHR flap has consistent vascular anatomy. It can be raised as an anterograde or retrograde flap for a contralateral or ipsilateral inset. FHR flap can be used in extensive composite nasal defects. This case series demonstrates that interposition vascular grafts are invariably needed and the possibility of using forearm vessels as grafts instead of DLCxF artery and vein.

Lower leg reconstruction after resection of a squamous cell carcinoma on necrobiosis lipoidica with a pedicled fibula and an extended anterolateral thigh flap-a case report

BACKGROUND

Extensive loss of soft tissue and bone due to neoplasia, trauma, or infection in extremities often leads to amputation.

CASE PRESENTATION

We present the case of a 72-year-old female patient presenting with an extended cutaneous squamous cell carcinoma of the lower leg, developed on top of necrobiosis lipoidica. After achieving the R0 resection, a 26 × 20-cm soft tissue and 15-cm tibial bone defect resulted. The contralateral leg had been lost due to the same disease 18 years before. We achieved a successful reconstruction of the leg using a pedicled fibula transplantation, an extended anterolateral thigh perforator flap, and an internal fixation with plate and screws. Two years after the original surgery, the patient is relapse-free and mobile, with adequate function of the reconstructed foot.

CONCLUSIONS

Our case presented a unique combination of pedicled fibula transplantation and free extended ALT perforator flap to reconstruct an extensive defect after resection of a rare cSCC on top of NL. In selected cases, the boundaries of limb salvage can be pushed far beyond the current standards of treatment.

Delto-acromial artery perforator flap combined with a radial forearm free flap as a "vascular bridge" for nasal reconstruction

Nasal reconstruction for total rhinectomy is challenging, especially if locoregional flaps are unavailable. Herein, we report the case of a nasal reconstruction combining a forearm free flap as "vascular bridge" and a Delto-Acromial Artery Perforator (DAAP) flap in its free form. The forearm free flap was used to restore missing elements of the nasal lining while the distal part of the radial pedicle has served as a donor vessel for the DAAP free flap which restores the nasal covering. A chondrocostal graft was used as a nasal framework. The nasal aspect at 24 months postop support the patient's satisfaction. The main advantages of the DAAP Flap are the pliability, relative hairless nature, skin thinness and its geographical proximity with the nose avoiding major dyschromia. Moreover, the anatomy consistency makes it easier to harvest, the underlying muscles are respected, and it allows for tension free primary closure without shoulder movement limitation.

Single incision thenar muscle reconstruction using the free functional pronator quadratus flap

Background

Injuries to the thenar muscle mass or the thenar branch of the median nerve and resulting loss of thumb opposition lead to a massive impairment of hand function. For decades, reconstructive approaches were based on tendon transfers. To broaden the reconstructive repertoire, we present the free functional pronator quadratus flap as a viable alternative for functional reconstruction and provide a specification for its indication. We demonstrate our surgical technique to a single incision reconstruction using the free functional pronator quadratus flap. Based on a series of three patients, which were analyzed for hand function using Kapandji’s score and the angle of Bourrel, grip strength and nerve conduction velocity in a two year follow up, we present an indication algorithm.

Results

After successful reinnervation of all flaps, we found an improvement of Kapandji’s score from 4.3 ± 0.94 preoperatively, to 8.7 ± 0.47 after two years. Accordingly, the angle of Bourrel decreased from 75.75 ± 3.45 degrees to 36.96 ± 3.68 degree. Grip strength also improved from 14 ± 2.2 kg to 26.2 ± 1.2 kg. No impairment of wrist pronation was observed.

Conclusion

We found excellent functional recovery of thumb opposition and strength, showing similar or even superior results compared to results from tendon transfers. With the benefit of a single incision surgery and therefore minimal donor site morbidity, this free functional muscle transfer is a viable alternative to classic tendon transfers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01308-x.

Free Flaps in Lower Extremity Reconstruction

Free tissue transfer to the lower extremity for limb salvage remains challenging. A comprehensive approach includes patient selection, flap selection, selection of the recipient vessels, flap dissection, flap preparation, microvascular anastomosis, flap inset, immediate postoperative care, intermediate postoperative care, and further follow-up care. Each step in this comprehensive approach has its unique considerations and should be executed equally to ensure an optimal outcome. Once acquired, some clinical experience along with adequate microsurgical skill, good surgical judgment, well instructed and step-by-step intraoperative execution, and a protocol-driven practice, successful free tissue transfer to the lower extremity can be accomplished.

Random-pattern versus perforator-based adipocutaneous skin paddles for postoperative monitoring of free muscle flaps-a comparative retrospective cohort study

INTRODUCTION

Free microvascular muscle flaps represent well-established reconstructive options for complex soft tissue defects. However, due to their lack of cutaneous capillary beds, they are difficult to monitor postoperatively. To this end, random and axial-pattern adipocutaneous skin paddles are often included. The objective of the study was to compare the impact of random-pattern versus perforator-based adipocutaneous skin paddles on operative efficacy and muscle flap safety.

METHODS

Between August 2014 and July 2016, a total of 120 free muscle flaps were included in this retrospective monocentric cohort study. Based on their skin-paddle type, they were either grouped into a 'perforator-based' (group Pb) or 'random-pattern' (group Rp) cohort. The electronic medical records and operative reports of all patients were subsequently reviewed and patient, defect, and flap characteristics of both groups were compared. The effect of the competing skin paddle types on the overall operative time, incidences of flap loss or microvascular complications, and total length of hospital stay were then assessed.

RESULTS

Group Pb comprised 72 flaps, whereas 48 flaps constituted group Rp. Patient, defect, and flap characteristics were similar between both groups. Groups Pb and Rp were comparable regarding patient age (group Pb: 61 (10-90) vs. Rp: 59 (13-81), p = 0.556), ASA (American Society of Anesthesiologists) class (group Pb: 3 (1-4) vs. Rp 3 (1-3), p = 0.977), and comorbidities, summarized by the Charlson comorbidity index (CCI; group Pb: 1 (0-4 vs. Rp: 1 (0-5), p = 0.295). Both types of monitoring skin paddles were equally reliable. There was no significant difference in the mean operation time between both groups (group Pb: 373 ± 122 min vs. Rp: 342 ± 84 min, p = 0.124). In-patient treatment after flap surgery and total length of hospital stay were significantly shorter in group Pb (group Pb: 24 ± 10 days vs. Rp: 32 ± 17 days, p = 0.002 and group Pb: 39 ± 15 vs. Rp: 48 ± 24, p = 0.022).

CONCLUSION

Perforator-based skin paddles are a reliable tool for postoperative perfusion monitoring of free muscle flaps and help avoid additional surgical interventions as opposed to their random-pattern counterparts. Thus, the overall and postoperative length of hospital stay is significantly reduced.

Free flap head and neck reconstruction in the elderly: what is the impact on quality of life?

Morphofunctional reconstruction is a pivotal aspect in the surgery of head and neck neoplasms: nowadays, microvascular free flap surgery represents the gold standard. In choosing the surgical technique, the effects on residual quality of life, especially in elderly people, usually considered more fragile and so often excluded from microsurgical procedures, must be taken into account. This multicentre study evaluated the quality of life index in patients more than 75 years of age and who underwent to head and neck microsurgical reconstruction. Data from patients aged > 75 years at the time of major head and neck reconstruction conducted with free flaps between 1 January 2005 and 30 June 2015 were analysed retrospectively. We administered the Italian version of Quality of Life questionnaire SF-36, at least 24 months after surgery. Results were compared to those for the general Italian population of the same age. We enrolled 39 patients with an average age of 80.6 years. The results did not differ significantly from the reference population. The international literature has already shown that chronologic age is not a valid parameter to determine the surgical treatment modality. Even considering the quality of residual life, our study supports the indication for free-flap reconstruction of head and neck defects in the elderly, confirming its effectiveness in this population.

Robot-Assisted Reconstruction in Head and Neck Surgical Oncology: The Evolving Role of the Reconstructive Microsurgeon

Transoral robotic surgery (TORS) is gaining more widespread use among head and neck surgical procedures. As experience grows with this technique, so do the indications of when and in which patients it can be used. Already established in the treatment of small oral cavity tumours, it is expanding into larger multi-site resections and resections, such as through-and-through-into-the-neck defects, that will require reconstruction. With robot-assisted surgery advancing, so robot-assisted reconstruction (RAR) is evolving. In this paper, we discuss the evolving role of reconstruction in post-TORS defects as well as the role of RAR in today's practice.

Re-introducing the delto-acromial perforator flap: Clinical experience and cadaver dissection

BACKGROUND

Although perforator flaps from the pectoral branch of the thoraco-acromial (TA) axis have been well-described, there are few reports of perforator flaps based on the delto-acromial (DA) branches. We have found a reliable perforator coming off the DA branch of the TA axis, and have named a flap based on this vessel the delto-acromial perforator (DAP) flap. We describe our experience with the DAP flap together with a fresh cadaver anatomical study.

METHODS

A retrospective review of all DAP flaps performed between December 2012 and January 2015 at our institution, with analysis of operative details, flap characteristics and surgical outcomes. We performed fresh cadaver dissection on 5 hemi-chest walls.

RESULTS

The main cutaneous perforator from the deltoid and/or acromial branches is found at the delto-pectoral groove, 8 cm lateral to the TA axis and 8 cm inferior to the acromio-clavicular joint. Five patients underwent DAP flap reconstruction. Three were pedicled and 2 were free flaps. Average pedicle length from the origin of the DA branch was 8 cm, with an arterial diameter of at least 1 mm and vein diameter 1.5 mm. All flaps survived completely. Cadaver dissection showed a consistent perforator arising from the common delto-acromial branch in 4 cadavers, and from the deltoid branch in 1 cadaver.

CONCLUSIONS

The DAP flap is a good addition to the armamentarium of reconstructive surgeons when a relatively thin fasciocutaneous flap with minimal hair is desired. It may be used for free tissue or locoregional transfer.

A Comparative Study on Microvascular Anastomosis of Vascularised Free Fibular Flap with Couplers and Suturing in Mandibular Reconstruction

INTRODUCTION

Successful outcome of any vascularised free flap basically depends upon the successful restoration of circulation in the flap after anastomosis. As the flap ischemic time is the significant factor which determines the outcome of any free flaps, due consideration is given to reduce the time for anastomosis for reperfusion. The present study compares and evaluates whether the usage of microvascular couplers with the conventional suturing reduce the ischemic time of the free flaps.

MATERIALS AND METHODS

Thirty patients were randomly divided into two groups (each group consisting of 15 patients) for mandibular reconstruction using free fibular microvascular flap. In group 1, microanastomosis was done with conventional suturing whereas microvascular couplers were used in group 2. Intraoperatively, patency, leakage and tissue perfusion were assessed. The time taken for anastomosis (time taken for suturing and applying couplers) and flap ischemic time (from the time of flap division from the donor site till the flap is reperfused after anastomosis) were calculated for both the groups.

RESULTS

Significant decrease in time for anastomosis was observed in group 2, which resulted in decrease in flap ischemic time and in overall operating time.