Monitoring free flaps using laser-induced fluorescence of indocyanine green: a preliminary experience

In a prospective, clinical study, the clinical utility of indocyanine green for intraoperative monitoring of free tissue transfer was evaluated. The study comprised 20 surgical patients undergoing elective microsurgical procedures. Indocyanine green angiography was performed intraoperatively, immediately after flap inset, and the operating team was blind to the fluoremetric findings. Thereafter, postoperative monitoring was done exclusively by clinical examination (color, temperature, time for recapillarization, and bleeding after puncture). Final outcome was compared with results of perioperative indocyanine (ICG)-imaging, and classified either as total flap loss, partial flap loss, or successful tissue transplantation. A total of 2 (10%) complications was recorded, and included one partial and one total flap loss. Both complications were detected by intraoperative ICG imaging. Another case of intraoperative subclinical arterial spasm at the place of microvascular anastomosis was revealed by dynamic ICG-videography. This flap did not develop postoperative complications. In conclusion, evaluation of perfusion by ICG imaging is feasible in all kinds of microsurgical flaps, irrespective of the type of tissue. Even though not meeting all the criteria of an ideal monitoring device, significant additional information can be obtained. In this study, cases with arterial spasm, venous congestion, and regional hypoperfusion were revealed by intraoperative ICG-videography. There was a strong correlation between intraoperative findings and clinical outcome.     

Leaving the perfusion zones? Individualized flap design in 100 free DIEP and ms-TRAM flaps for autologous breast reconstruction using indocyanine green angiography

BackgroundThere is still no consensus regarding the ideal zoning in abdominal-based autologous breast reconstruction using free DIEP or ms-TRAM flaps. In particular, the perfusion pattern of the flap according to the number of perforators used and their location remains controversial. In this study, the perfusion of free DIEP and ms-TRAM flaps is assessed intraoperatively and analyzed with regard to different perfusion patterns.MethodsA retrospective analysis of 100 free flaps for breast reconstruction was performed. Following complete flap harvest, we used indocyanine green angiography for perfusion analysis. By applying two different contour levels, DIEP flaps with lateral or medial perforators and ms-TRAM flaps were assessed for their respective perfusion patterns.ResultsNo statistically significant differences were found in the size of the perfusion area between the different flap types when applying the contour level of 20% (p >0.05). For the contour level of 30%, however, statistically significant differences were found between DIEP flaps with medially or laterally located perforators (p = 0.038). Laterally or medially located perforators in DIEP flaps showed no significant differences in their ability to cross the midline (contour level 20%, p = 0.068; contour level 30%, p = 0.058).ConclusionConsidering the variability of the perfusion of the abdominal wall and the high sensitivity of indocyanine green angiography for their detection, the abdominal zonings play a minor role. By using intraoperative indocyanine green angiography, a precise and patient-specific free flap surgery for autologous breast reconstruction is possible independent of perforator location.     

The application of indocyanine green fluorescence angiography in plastic surgery

In flap reconstruction of complex defects the perfusion of the reconstructive flap is critical to the ultimate success of the reconstruction. This is especially true in perforator-based flaps where it can be difficult to assess the adequacy of perfusion in the operating room. However, the ability to definitively determine the degree of flap perfusion is imperative to clinical decision-making. An emerging technology using near-infrared angiography with indocyanine green (ICG) dye may significantly improve the immediacy and accuracy of the assessment of flap perfusion. This article reviews the current state of ICG angiography and its use in clinical practice in plastic surgery. There are 17 case series, including a total of 386 patients, published in the literature using ICG angiography in various plastic surgical procedures. ICG angiography may aid flap design and assessment in the intraoperative/postoperative settings, reduce complications, and ultimately improve outcomes.     

吲哚菁绿血管造影在乳腺癌术后乳房重建中的应用

目的探讨乳房重建术中判断组织血供的可视化方法。方法 2014年7月至2015年1月,在4例乳腺癌患者的乳房重建手术中,应用吲哚菁绿(ICG)荧光血管造影技术,在血液灌注可视化的情况下对皮瓣进行修整。结果ICG造影结果与组织血供的临床判断一致,3例患者未出现皮瓣血运障碍,1例患者出现皮瓣部分血运障碍。结论 ICG血管造影可应用于各种类型的乳房切除术后乳房重建,有助于降低皮瓣坏死的发生率和严重性。     

An investigation of the application of laser-assisted indocyanine green fluorescent dye angiography in pedicle transverse rectus abdominus myocutaneous breast reconstruction

BACKGROUND:

Pedicle transverse rectus abdominus myocutaneous (pTRAM) flaps remain the most common method of autologous tissue breast reconstruction. Using pTRAM flaps, complications often arise postoperatively, secondary to inadequate circulation. Tissues from distant angiosomes are associated with poorer perfusion, but this differs among patients. Many modalities have been used to reduce the risk of complications, but none have achieved widespread application. The authors believe that laser-assisted indocyanine green fluorescent dye angiography (LA-ICGA) can potentially reduce the risk of complications.

METHODS:

In two routine, single-pedicle, ipsilateral pTRAM flaps, LA-ICGA imaging was performed following the division of the distal rectus muscle and deep inferior epigastric pedicle. The resulting images were used to guide design of the flap and debridement.

RESULTS:

In case 1, good perfusion was observed in zone 1 and part of zone 2. In case 2, good perfusion was observed in zone 1 and 50% of zone 3, with little perfusion in zone 2. In both cases, tissues with poor perfusion were debrided before transfer and inset. In both patients, there were no issues with wound healing, tissue necrosis or fat necrosis.

CONCLUSIONS:

The variability of perfusion of the pTRAM flap among individuals is well appreciated. LA-ICGA helped to determine the limits of good perfusion and, therefore, the limits of tissue to be preserved for transfer and inset. This helped to avoid harvesting poorly perfused tissue that would have almost certainly experienced necrosis and, ultimately, would have reduced the risk of postoperative complications.     

Free hemiback flap with surgical delay for reconstruction of extensive soft tissue defect: A case report

A delay procedure allows for reliable tissue transfer in random pattern flaps and axial pattern flaps. However, delay procedures have not been studied in free flaps. In this report, we present a case involving the use of a free extended latissimus dorsi musculocutaneous flap (hemiback flap) that included half of the total back skin and was based on thoracodorsal vessels for reconstruction of an extensive soft tissue defect of the flank and waist. The flap was tailored in combination with a delay procedure. Intraoperative indocyanine green fluorescence angiography indicated profuse perfusion except for the most inferomedial part of the flap, which was discarded. The flap survived. A free hemiback flap may offer a valuable option for reconstruction of extensive soft tissue defects. To our knowledge, this is the first report to demonstrate a free flap made in combination with a delay procedure. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.     

Wound closure by means of free flap and arteriovenous loop: Development of flap autonomy in the long‐term follow‐up

Free flaps in combination with arterial reconstruction by means of arteriovenous loops or bypass have, meanwhile, been established as a therapeutic option in defect reconstruction for areas without recipient vessels. Our aim was to analyse the long‐term performance, flap autonomy, and the flap perfusion. Patients receiving this combined reconstruction at a single‐centre institution were included. During follow‐up examination, the patency of arterial reconstruction was investigated by duplex ultrasound. Flap micro‐circulation was assessed by laser Doppler flowmetry and white light tissue spectrometry (O2C) as well as by indocyanine green fluorescence angiography. Twenty‐three patients could be clinically followed up. Duplex ultrasound showed, in four cases, arterial pedicle occlusion in spite of vital flap. Comparison of the O2C perfusion parameters between flaps with occluded pedicles and those with intact inflow showed no significant difference (parameters sO2: P = .82; Flow: P = .31). Similar results were obtained by fluorescence angiography; no significant difference could be detected between both groups (parameters Ingress P = .13; Ingressrate P = .54). Combined vascular reconstruction with free tissue transfer is associated with a good long‐term outcome and wound closure. Even after flap transplantation to areas with critical tissue perfusion, the flap can develop autonomy and thus survive after pedicle occlusion.     

Face transplant perfusion assessment using near-infrared fluorescence imaging

BackgroundComposite tissue allografts (CTAs) including partial face transplantation have been achieved clinically. However, risks of complications including tissue ischemia, rejection, and transplant failure are significant. Safe and effective techniques to assess perfusion are needed to decrease complications in composite tissue flaps. Near-infrared (NIR) fluorescence imaging has been previously shown to provide a real-time, intraoperative evaluation of perfusion. This study investigates the use of NIR imaging in partial face CTA harvest.MethodsWe created hemifacial CTAs (n = 8) using an established porcine model. This included ear cartilage, nerve, lymphoid tissue, muscle, and skin with perfusion by the carotid artery and external jugular vein. We injected animals systemically with indocyanine green and obtained NIR fluorescence images simultaneously with color video. In addition, we assessed the elevated hemifacial flaps using standard of care (i.e., clinical examination and Doppler).ResultsFlap design was facilitated by NIR imaging with localization of perforators to the hemifacial CTA flap. In particular, an arterial and venous phase could be clearly identified. We assessed perfusion of the flap by NIR fluorescence intensity after injection of indocyanine green. Sequential clamping of the artery and vein confirmed correlation of perfusion deficits with NIR imaging as well as with clinical examination and Doppler.ConclusionsEvaluation and assessment of perfusion are important in facial transplantation. The results from our pilot study indicate that NIR imaging has the capability to assess perfusion of partial facial CTAs. This emergent technology shows promise in assessing tissue perfusion in a composite flap.     

Bedside monitoring of free flaps using ICG-fluorescence angiography significantly improves detection of postoperative perfusion impairment##

After microvascular tissue transfer, free flaps require meticulous postoperative surveillance. The purpose of this study was to evaluate the effect and applicability of indocyanine green fluorescence angiography (ICG-FA) in bedside monitoring of free flaps postoperatively, especially considering its role in correctly identifying vascular thromboses. Between February 2012 and October 2015, 210 free flaps used for defect reconstruction were analyzed. The flaps were monitored bedside for flap perfusion compromise by clinical examination and by ICG-FA in a standardized procedure in the first 3 postoperative days. Data were evaluated retrospectively with respect to the etiology of the perfusion compromise with special focus on vascular thromboses and revision rates. In total, 23 vascular thromboses were identified. The combination of clinical examination and ICG-FA (85%) was most successful in determining the prevalence of vascular thromboses. In 41 cases, clinical and/or ICG-FA examinations indicated revision surgery. The flap salvage rate after revision was 77% (31 cases), which results in an overall flap survival rate of 96%. The revision rates were reduced over the study time from 22% in 2012 to 12% in 2015. ICG-FA as an adjunct to clinical examination of free flaps can help in correctly identifying vascular thromboses and can help decide if revision surgery is necessary in not obvious cases of perfusion compromise.     

自体乳房重建中皮瓣相关并发症影响因素分析及术中使用吲哚菁绿造影的经济学效益

目的探讨自体乳房重建中皮瓣相关并发症的影响因素,以及术中使用吲哚菁绿(indocyanine green,ICG)造影的经济学效益。方法回顾分析2013年7月-2018年6月收治的符合选择标准的150例自体乳房重建的乳房切除术后患者(152个乳房)。对年龄、体质量指数、术前新辅助化疗(neoadjuvant chemotherapy,NC)、胸部放疗史、合并糖尿病、供区手术史、胸壁重建、重建时机、皮瓣类型、术中ICG造影进行单因素分析,初步筛选单因素分析中有统计学意义的临床因素,纳入皮瓣相关并发症及皮瓣局部坏死的logistic多因素回归分析(逐步后退法)。根据以上多因素分析结果,将患者分为4组:ICG+NC组(A组)、ICG+非NC组(B组)、非ICG+NC组(C组)、非ICG+非NC组(D组),计算每组患者的人均额外治疗费用(ICG造影费用+处理皮瓣相关并发症的费用)。结果术后152个皮瓣均成活。共有33个皮瓣发生皮瓣相关并发症,包括22个皮瓣局部坏死、9个局部感染、5个血肿、5个单纯脂肪液化、2个吻合口血栓形成。单因素分析显示,术前NC、皮瓣类型及术中ICG造影是发生皮瓣相关并发症的影响因素(P<0.05)。多因素分析显示,术前NC、未使用ICG造影是发生皮瓣相关并发症的危险因素(P<0.05),也是发生皮瓣局部坏死的危险因素(P<0.05)。对于NC患者,术中使用ICG造影会大大节省人均额外治疗费用,A组较C组人均额外治疗费用少花费1378元。对于未行NC者,术中使用ICG造影会增加人均额外治疗费用,B组较D组人均额外治疗费用多花费747元。结论在自体乳房重建中,ICG造影可降低皮瓣相关并发症的发生率,尤其是皮瓣局部坏死发生率;而NC则相反。对于非NC患者,ICG造影的性价比不高,经济条件允许下可使用;但对于NC患者,ICG造影性价比较高,建议使用。     

Indocyanine Green Angiography for Evaluation of Gastric Conduit Perfusion during Esophagectomy - First Experience

Background : A complication of esophageal surgery is leakage at the anastomosis site and one of the factors involved in this complication is poor blood flow in the distal portion of the tube. The aim of this study was to evaluate the feasibility of indocyanine green fluorescence imaging as a method of determining the perfusion of the gastric conduit after esophagectomy.

Methods : We analysed 15 consecutive patients who underwent transhiatal esophagectomy (THE) due to cancer. All of the patients had reconstruction of the gastrointestinal tract using the gastric conduit. Before performing the anastomosis, the blood flow in the area of the tube was evaluated using intravenous indocyanine green and observing its vascular flow with a camera equipped with an infrared laser.

Results : In all cases it was possible to visualize the vascular flow of indocyanine green within the region of the gastric tube. The fluorescence imaging system showed vascular insufficiency of the distal gastric conduit in 4 patients - in all of these patients the anastomosis was performed end-to-side and there was no subsequent leak. Leakage at the anastomosis site was observed in 1 patient (6,66%). The leak was observed in the 9^th postoperative day, despite visualization of a good vascular supply of the tube.

Conclusions : Indocyanine green fluorescence imaging of gastric tube allows for intraoperative modifications, but it must be noted that the patient’s comorbidities and general health may also increase the risk of anastomosis leakage.     

硬脊膜内背侧动静脉瘘的显微外科治疗

目的 探讨硬脊膜内背侧动静脉瘘的显微外科治疗及其疗效,初步探索术中吲哚菁绿荧光血管造影的应用.方法 2004年1月至2008年8月共有24例硬脊膜内背侧动静脉瘘患者进行了半椎板切除显微外科治疗并获得随访.其中2例为先接受介入栓塞治疗,后因复发再接受外科手术治疗.3例接受术中吲哚菁绿荧光血管造影.脊髓功能评价采用改良阿米诺夫量表,结合影像学检查结果对术后疗效进行综合评价.结果 术后平均随访36个月,影像学随访未见病变残留或复发.脊髓功能评价16例为优,阿米诺夫评分平均0.7分;4例为良,平均4.8分;3例为中,平均6.7分;1例为差,平均9.0分.综合疗效评价,治愈16例,改善6例,无变化2例.结论 单侧半椎板切除入路显微外科治疗足对硬脊膜内背侧动静脉瘘的有效治疗方法,术中吲哚菁绿荧光血管造影有助于手术.     

Indocyanine green fluorescence angiography in pediatric intestinal resections: A first prospective mixed methods clinical trial

BackgroundThe aim of this study was to establish the feasibility and safety of the use of indocyanine green technology during pediatric intestinal resections. While indocyanine green fluorescence angiography (ICG-FA) has been advocated as an imaging technique to assess bowel perfusion in adults, few studies have evaluated this technology in a pediatric context.MethodsA prospective clinical trial was conducted. Patients 16 years old or younger undergoing a surgery potentially requiring an intestinal resection were eligible. Patients received a standardized intravenous injection of indocyanine green and intestinal perfusion was evaluated. The study endpoints included safety, impact on bowel resection and feasibility and acceptance of ICG-FA in this population.ResultsFrom May 2020 to March 2021, 30 consecutive patients were included in this trial. Final analysis was done on 28 patients with a median age of 15.00 [6.36,85.00] weeks and weight of 5.58 [3.64,11.70] kg at surgery. Adequate fluorescence was achieved in less than one minute for all cases with an average dose of 0.14 mg/kg. No adverse event related to indocyanine green occurred. ICG-FA versus standard assessment of potential resection sites differed in 62% (95% IC 0.41–0.82) of our cases. Qualitative analysis demonstrated that 95% of the surgical team agreed that ICG-FA was safe.ConclusionsThe use of ICG-FA is feasible and safe for pediatric intestinal resections. Introduction of ICG-FA was simple and acceptance rates were high within the surgical team. This fluorescence imaging may be a valuable imaging technology for intestinal resections in pediatric surgery.     

Tailoring through Technology: A Retrospective Review of a Single Surgeon's Experience with Implant‐Based Breast Reconstruction before and after Implementation of Laser‐Assisted Indocyanine Green Angiography

Reported complication rates of implant‐based breast reconstruction in the literature exceed 50%, with mastectomy skin flap necrosis reported to occur in up to 25% of cases. Laser‐assisted indocyanine green angiography (LA‐ICGA) technology allows the surgeon to optimize preservation of the mastectomy skin flap while avoiding skin necrosis. The purpose of this study was to determine if outcomes of breast reconstruction are beneficially affected by using LA‐ICGA. A total 269 consecutive women (467 breast reconstructions) undergoing implant‐based breast reconstruction from 2008 to 2013 were examined. The complication rates of those who underwent reconstruction prior to the implementation of LA‐ICGA were compared with those who were reconstructed after implementation of LA‐ICGA. A total of 254 consecutive breast reconstructions were performed prior to implementation of LA‐ICGA, and 213 breasts were reconstructed with the use of LA‐ICGA. After implementation of LA‐ICGA System, the rate of mastectomy skin flap necrosis decreased by 86% (6.7% versus 0.9%, p = 0.02). The overall complication rate prior to LA‐ICGA was 13.8% compared with 6.6% with the use of LA‐ICGA (p = 0.01). After LA‐ICGA was incorporated, the percentage of patients undergoing single‐stage reconstruction increased from 12% to 32% (p = <0.001). Implementation of LA‐ICGA provides the surgeon with an objective assessment of mastectomy flap perfusion resulting in a trend toward overall reduction in complications as well as an 86% decrease in the rate of subsequent skin necrosis. The objective assessment of mastectomy flap perfusion allows the surgeon to tailor breast reconstruction intraoperatively, in real‐time, adjusting for the individual patient's mastectomy flap perfusion.     

Intraoperative Assessment of Kidney Allograft Perfusion by Laser-Assisted Indocyanine Green Fluorescence Videography

Background

Kidney allograft function crucially depends on the quality of organ perfusion. Duplex sonography, however, frequently reveals hypoperfused segments that remained undetectable to visual inspection intraoperatively. To date, no imaging system supplementing the surgeon's experience has achieved clinical acceptance. The present work examines whether laser-assisted indocyanine green (ICG) fluorescence-videography can be used as a safe and sensitive technique for the intraoperative assessment of renal allograft perfusion.

Methods

Intraoperative assessment of organ perfusion by laser-assisted ICG fluorescence videography (IC-VIEW) was performed in 10 consecutive de novo renal transplantations. The IC-VIEW system allows the visualization of graft perfusion by the fluorescein dye ICG that emits infrared light after exposure to laser light.

Results

Perfusion measurements were successful in all 10 transplant recipients. Fluorescence videography produced brilliant, sharply contrasted images of the organs, allowing the detection of even small perfusion deficits. Remarkably, this technique detected 1 large perfusion defect that had remained imperceptible to visual inspection. Repositioning of the graft led to a homogeneous overall perfusion. There were no complications with the ICG injection or the imaging device.

Conclusion

Laser-assisted ICG fluorescence videography is a feasible and safe technique for the intraoperative assessment of renal allograft perfusion.     

A new approach to preexisting vertical midline abdominal scars with crossover DIEP flap breast reconstruction

Breast reconstruction using a free transverse rectus abdominis myocutaneous flap or a deep inferior epigastric perforator (DIEP) flap is a challenge in patients with a vertical midline abdominal scar due to the poor perfusion of the lower abdominal skin ellipse across the midline. In such patients, only one half of the abdominal skin ellipse can be used with certainty, and this limits the amount of tissue available for reconstructing the breast. Two cases of breast reconstruction in patients with a lower midline abdominal scar are presented using the DIEP flap, in which the poor perfusion across the midline scar was overcome by a technique of crossover anastomoses between the two deep inferior epigastric pedicles. Reliable perfusion of the entire lower abdominal skin ellipse was achieved. This crossover anastomoses technique overcomes the poor perfusion imposed by the vertical midline abdominal scar and enables DIEP flap breast reconstruction to be offered to women with midline abdominal scars. © 2009 Wiley‐Liss, Inc. Microsurgery, 2010.     

Intraoperative use of dynamic infrared thermography and indocyanine green fluorescence video angiography to predict partial skin flap loss

Inadequate perfusion is the most common cause of partial flap loss in reconstructive surgery. Intraoperative monitoring of flap perfusion may prevent such loss. This study compared indocyanine green fluorescence angiography (ICG-FA) and dynamic infrared thermography (DIRT) in their ability to predict intraoperatively the percentage of flap survival in a caudally based McFarlane flap in 10 male Wistar rats. The intraoperative images of both techniques were subjectively and objectively analysed. The percentage of flap survival, as judged from the digital colour photographs 7 days post-operatively, was 69 ± 3%. Objective analysis of flap survival based on intraoperative DIRT and ICG-FA (74 vs 63%, respectively) correlated quite well with the subjective measurements (75 ± 2 vs 59 ± 4%, respectively). However, intraoperative ICG-FA images underestimated flap survival by 6–10%, while intraoperative DIRT images overestimated the flap survival by 5–6%. The authors conclude that intraoperative use of ICG-FA and DIRT can provide valuable information on areas with inadequate perfusion as long as their limitations are respected.     

Breast reconstruction with superior epigastric artery perforator (SEAP) free flap: Report of two cases

The deep inferior epigastric artery perforator (DIEP) flap is the gold standard for autologous breast reconstruction. When the DIEP pedicle is damaged, alternative perforator flaps are harvested from sites with less donor tissue, such as the thigh. Pedicled superior epigastric artery perforator (SEAP) flaps have been recently described for reconstruction of inferior partial breast defects. The purpose of this report is to show the surgical technique of the free SEAP flap for reconstruction of the entire breast in two patients. The authors describe two patients where the DIEP pedicle was unavailable. The first patient was 53 years old, with body mass index (BMI) 22.7, while the second patient was 60 with BMI 32.4. The donor site was marked as for a DIEP, and two lateral row perforators were selected in each case. Flaps were designed to cross the midline, with adequate perfusion confirmed via indocyanine green angiography. Both flaps were rotated 90° counterclockwise for inset into the chest. Flap size and weight for the two patients were: 24 × 15 cm and 350 g; and 25 × 15 cm and 400 g. Both patients had a routine postoperative course without complications. Length of follow-up was 155 and 158 days, respectively. We believe that the free SEAP flap is a promising technique in select patients who require an alternative to the DIEP for autologous breast reconstruction.     

Intraoperative evaluation of blood perfusion by laser-assisted indocyanine green angiography after ex vivo vascular reconstruction of intrahilar renal artery aneurysm

The surgical reconstruction of intrahilar renal artery aneurysms (RAAs) is a difficult surgery because of complex anatomy. We present a case of right intrahilar RAA diagnosed in a 67-year-old man. We performed ex vivo reconstruction using an organ preservation solution to prevent postoperative renal failure. We assessed graft patency and blood perfusion was assessed by laser-assisted indocyanine green angiography using the SPY system after autotransplantation. Postoperative renal insufficiency was not observed. The results demonstrate that ex vivo reconstruction of intrahilar RAAs using an organ preservation solution, and graft patency and blood perfusion evaluation using the SPY system are effective methods for preserving renal function.