Daniel Chubb

The efficacy of postoperative monitoring: a single surgeon comparison of clinical monitoring and the implantable Doppler probe in 547 consecutive free flaps.

Background: An important element in achieving high success rates with free flap surgery has been the use of different techniques for monitoring flaps postoperatively as a means to detecting vascular compromise. Successful monitoring of the vascular pedicle to a flap can potentiate rapid return to theater in the setting of compromise, with the potential to salvage the flap. There is little evidence that any technique offers any advantage over clinical monitoring alone. Methods: A consecutive series of 547 patients from a single plastic surgical unit who underwent a fasciocutaneous free flap operation for breast reconstruction [deep inferior epigastric artery perforator (DIEP) flap, superficial inferior epigastric artery (SIEA) flap, or superior gluteal artery perforator (SGAP) flap] were included. A comparison was made between the first 426 consecutive patients in whom flap monitoring was performed using clinical monitoring alone and the subsequent 121 patients in whom monitoring was achieved with the Cook‐Swartz implantable Doppler probe. Outcome measures included flap salvage rate and false‐positive rate. Results: There was a strong trend toward improved salvage rates with the implantable Doppler probe compared with clinical monitoring (80% vs. 66%, P = 0.48). When combined with the literature (meta‐analysis), the data prove statistically significant (P < 0.01). There was no statistical difference between the groups for false‐positive rates. Conclusion: Flap monitoring with the implantable Doppler probe can improve flap salvage rates without increasing the rate of false‐positive takebacks.

The efficacy of clinical assessment in the postoperative monitoring of free flaps: a review of 1140 consecutive cases.

BACKGROUND Effective postoperative monitoring of the vascular pedicle to a free flap can potentiate rapid return to the operating room in the setting of compromise, allowing for the potential to salvage the flap. The only ubiquitous method for postoperative monitoring of free flaps is clinical bedside monitoring, but although the use of clinical monitoring may be inferred in large reported series of free flaps, there has been little discussed in the literature of specific clinical outcome measures. METHODS The authors present their experience with 1140 consecutive cases of free tissue transfer and the use of clinical monitoring as a sole method of monitoring, and subgroup analysis of different recipient sites. RESULTS There were 94 take-backs, four of which had no pedicle compromise (false-positives) and there were four false-negatives. The overall flap salvage rate was 62.8 percent and the false-positive rate was 0.4 percent. Subgroup analyses demonstrated statistically significant differences between recipient sites for the false-positive rates: fewer false-positives with breast reconstruction cases (p < 0.05) and significantly more false-positives in the extremity group (p < 0.05). There was an improved flap salvage rate in cases of venous compromise compared with arterial compromise (69 percent versus 51 percent, p = 0.015). CONCLUSIONS This largest reported series to date provides an outcome-based analysis of postoperative monitoring for free flaps, providing a benchmark standard against which adjunctive monitoring techniques can be compared. Future studies need to be assessed in the context of individual recipient sites, with significant differences in monitoring outcomes between sites.

True and 'choke' anastomoses between perforator angiosomes: part II. dynamic thermographic identification.

Background: Cadaveric studies have revealed that cutaneous perforators are linked by either reduced-caliber “choke” arteries, or by vessels without change in caliber, the true anastomoses. These true anastomotic vessels are often found in parallel with the cutaneous nerves and accompanying veins, and are associated both experimentally and clinically with larger areas of flap survival. The Doppler probe and computed tomographic angiography are already used preoperatively to determine perforator locations but currently cannot reveal the type of anastomotic connections. Methods: Thermal images were taken in a previously described fashion and compared with both computed tomographic angiographic studies where available and with cadaveric angiographic studies previously performed by the authors’ laboratory. Results: Perforators larger than 1 mm were accurately localized by thermography when compared with computed tomographic angiography. Perforator angiosome rewarming closely approximated a log-based line of best fit. Interperforator zones were variable in their rewarming and correlated with known anatomical patterns of true and choke anastomoses between perforator angiosomes. Conclusions: Thermography now offers a new modality with which to bridge the gap not only by identifying the perforator “hot spots” but also by the robustness of their interconnections. The pattern of these interconnections seen on thermographic imaging has in turn been found to match those seen in the authors’ cadaveric studies.

Postoperative Monitoring of Free Flaps in Autologous Breast Reconstruction : A Multicenter Comparison of 398 Flaps Using Clinical Monitoring, Microdialysis, and the Implantable Doppler Probe

Many techniques for flap monitoring following free tissue transfer have been described; however, there is little evidence that any of these techniques allow for greater rates of flap salvage over clinical monitoring alone. We sought to compare three established monitoring techniques across three experienced microsurgical centers in a comparable cohort of patients. A retrospective, matched cohort study of 398 consecutive free flaps in 347 patients undergoing autologous breast reconstruction was undertaken across three institutions during the same 3-year period, with a single form of postoperative monitoring used at each institution: clinical monitoring alone, the Cook-Swartz implantable Doppler probe, or microdialysis. Both objective and subjective measures of efficacy were assessed. Clinical monitoring alone, the implantable Doppler probe, and microdialysis showed statistically similar rates of flap salvage. False-negative rates were also statistically similar (only seen in the clinically monitored group). However, there was a statistically significant increase in false-positive alarms causing needless take-backs to theater in the microdialysis and implantable Doppler arms, P < 0.001. This study did not find any technique superior to clinical monitoring alone. New monitoring technologies should be compared objectively with clinical monitoring as the current standard in postoperative flap monitoring.

Preoperative Imaging for Perforator Flaps in Reconstructive Surgery A Systematic Review of the Evidence for Current Techniques

BackgroundAlthough preoperative imaging of perforator vasculature in planning microvascular reconstruction is commonplace, there has not been any clear demonstration of the evidence for this practice, or data comparing the many available modalities in an evidence-based approach. This article aims to

Current Evidence for Postoperative Monitoring of Microvascular Free Flaps: A Systematic Review

BackgroundDespite a plethora of monitoring techniques reported in the literature, only a small number of studies directly address clinical relevant end points, such as the flap salvage rate and false-positive rate. MethodWe conducted a systematic review of current evidence regarding the postoperative monitoring of microvascular free-tissue transfer via extensive electronic and manual search and perusing databases, such as PubMed, Cochrane, American College of Physicians (ACP) Journal Club, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Excerpta Medica Database (EMBASE), and Ovid MEDLINE. The included literature (n = 184 publications) was critically appraised using March 2009 Oxford Centre for Evidence-Based Medicine definitions, focusing on the evidence for the efficacy of each technique in improving the flap salvage rate of compromised flaps. ResultThere is a paucity of outcome-based studies, with only implanted Doppler probes, near-infrared spectroscopy, laser Doppler flowmetry, quantitative fluorimetry, and digital photography assessment using smartphones having been demonstrated in comparative studies to improve flap salvage rate. Currently, the implantable Doppler probe is the technique with the largest number of comparative studies and case series to demonstrate its effectiveness compared with clinical monitoring. ConclusionsFuture studies need to evaluate the most promising monitoring techniques further with a focus on assessing clinically relevant outcomes, such as the flap salvage rate and the false-positive rate, and not simple clinical series reporting patient and physician satisfaction.

The variability of the Superficial Inferior Epigastric Artery (SIEA) and its angiosome: a clinical anatomical study

Introduction: The superficial inferior epigastric artery (SIEA) is a useful pedicle in supply to the lower abdominal integument, with its use sparing damage to rectus abdominis muscle or sheath. However, it is limited in usefulness due to its anatomical variability. While previous anatomical studies have been limited in number and study design, the use of preoperative imaging has enabled the analysis of this vasculature in large numbers and greater anatomical detail. Methods: A clinical anatomical study of 500 hemi‐abdominal walls in 250 consecutive patients undergoing preoperative computed tomographic angiography (CTA) prior to autologous breast reconstruction was undertaken. The presence, size, location, and branching pattern of the SIEA were assessed in each case. Results: The SIEA was identified in 468 cases, an incidence of 94%. Its mean diameter was 0.6 mm, and in 24% of cases was of a diameter >1.5 mm. SIEA location was highly variable, with mean position 2‐cm lateral to the linea semilunaris (range 0–8 cm lateral), and relationship to the superficial inferior epigastric vein (SIEV) was also highly variable, with the distance between them ranging from 0.3 to 8.5 cm apart. SIEA branches directly crossed the abdominal midline in 5% of cases. Larger SIEA diameters correlated with a decrease in diameter of ipsilateral DIEA perforators. Conclusion: The SIEA is present more frequently than previously demonstrated, but is typically too small for use in free tissue transfer. The variable degree of SIEA branching suggests that its territory of supply is also variable, and that preoperative imaging may be useful in planning SIEA flaps.

Technology‐assisted and sutureless microvascular anastomoses: Evidence for current techniques

Background: Since the birth of reconstructive microvascular surgery, attempts have been made to shorten the operative time while maintaining patency and efficacy. Several devices have been developed to aid microsurgical anastomoses. This article investigates each of the currently available technologies and attempts to provide objective evidence supporting their use. Methods: Techniques of microvascular anastomosis were investigated by performing searches of the online databases Medline and Pubmed. Returned results were assessed according to the criteria for ranking medical evidence advocated by the Oxford Centre for Evidence Based Medicine. Emphasis was placed on publications with quantifiable endpoints such as unplanned return to theatre, flap salvage, and complication rates. Results: There is a relative paucity of high‐level evidence supporting any form of assisted microvascular anastomosis. Specifically, there are no randomized prospective trials comparing outcomes using one method versus any other. However, comparative retrospective cohort studies do exist and have demonstrated convincing advantages of certain techniques. In particular, the Unilink™/3M™ coupler and the Autosuture™ Vessel Closure System® (VCS®) clip applicator have been shown to have level 2b evidence supporting their use, meaning that the body of evidence achieves a level of comparative cohort studies. Conclusion: Of the available forms of assisted microvascular anastomoses, there is level 2b evidence suggesting a positive outcome with the use of the Unilink™/3M™ coupler and the Autosuture™ VCS® clip applicator. Other techniques such as cyanoacrylates, fibrin glues, the Medtronic™ U‐Clip®, and laser bonding have low levels of evidence supporting their use. Further research is required to establish any role for these techniques.

Improving the utility and reliability of the deep circumflex iliac artery perforator flap: the use of preoperative planning with CT angiography.

Background: The deep circumflex iliac artery (DCIA) is rarely used as a perforator flap, despite a clear clinical need for thin osteocutaneous flaps, particularly in head and neck reconstruction. The poor adoption of such a flap is largely due to a poor understanding of the perforators of the DCIA, despite recent publications demonstrating suitable vascular anatomy of the DCIA perforators, particularly evident with the use of preoperative computed tomographic angiography (CTA). We have applied this method of peroperative imaging to successfully select those patients suitable for the DCIA perforator flap and use it clinically. Methods: We present a case series of patients who underwent DCIA perforator flap reconstruction following preoperative planning with CTA. Imaging findings, clinical course, and outcomes are presented. Results: Six out of seven patients planned for DCIA perforator flap reconstruction underwent a successful DCIA perforator flap, with imaging findings confirmed at operation, and without any flap loss, hernia, or other significant flap‐related morbidities. Because of abberent anatomy and change in defect following excision of pathology, one patient was converted to a free fibular flap. Conclusion: With preoperative CTA planning, the DCIA perforator flap is a versatile and feasible flap for reconstruction of the mandible and extremities.

Modern adjuncts and technologies in microsurgery: an historical and evidence-based review.

While modern reconstructive surgery was revolutionized with the introduction of microsurgical techniques, microsurgery itself has seen the introduction of a range of technological aids and modern techniques aiming to improve dissection times, anastomotic times, and overall outcomes. These include improved preoperative planning, anastomotic aides, and earlier detection of complications with higher salvage rates. Despite the potential for substantial impact, many of these techniques have been evaluated in a limited fashion, and the evidence for each has not been universally explored. The purpose of this review was to establish and quantify the evidence for each technique.