Microvascular Free Flaps

Vasopressor use in partial flap necrosis in free flap transplant patients with vascular comorbidities: A retrospective study

Intraoperative use of vasopressors in free flap surgeries is controversially debated. The predominant concern is that pedicle blood supply will decrease leading to post-operative complications. This study examined the role of intraoperative vasopressors, specifically norepinephrine, in free flap partial necrosis based on the patients' comorbidities. We retrospectively analyzed 192 patients who received free flap treatment between 2006 and 2021 and were stratified based on vascular comorbidities. We assessed the role of intraoperative vasopressors using multivariate analysis. Patients who were administered vasopressors did not have a significantly higher risk of partial flap necrosis compared to patients who were not administered vasopressors (OR: 1.439, 95% CI: 0.618-3.348, p=0.399). Upon stratifying by vascular comorbidities, we found that patients with two or more vascular comorbidities who were administered vasopressors had a significantly higher risk of developing flap necrosis (OR: 3.882, 95% CI: 1.266-14.752, p=0.046), indicating that vasopressor use in patients with multiple vascular comorbidities is a risk factor for partial flap necrosis. To minimize the risk of flap marginal necrosis in patients with vascular comorbidities, we recommend limited use of vasopressors or minimizing the flap area to preserve vascularization.

[Treatment strategies for fracture-related infections with concurrent soft tissue damage]

Fracture-related infections are the predominant complication following surgical fracture treatment. The distal lower leg, e.g., in pilon tibial fractures, is at a high risk of infection due to poor soft tissue coverage, particularly in cases of open fractures in this area. Fracture-related infections with significant soft tissue damage require special attention alongside treatment of the infection itself. In general, the principle is that healing of fracture-related infection is not possible without sufficient soft tissue coverage. Therefore, it is crucial to integrate both soft tissue damage and fracture-related infection into a comprehensive treatment plan from the beginning. An interdiscpilinary treatment approach between trauma and plastic surgery is often necessary and beneficial. In cases, where fracture fixation devices or bone is exposed, mid- or long-term use of vacuum-assisted wound therapy is not advisable due to a higher risk of reinfection. Hence, an interdisciplinary treatment strategy involving trauma and plastic surgery should prioritize early soft tissue closure, referred to as the "orthoplastic approach". If this cannot be done in the own hospital, early patient transfer is indicated to ensure optimal interdisciplinary therapy with early soft tissue closure and simultaneous trauma surgical treatment to control the infection and enable bone healing. Free fasciocutaneous or muscle flap techniques in combination with adequate trauma surgical and antibiotic therapy lead to good reliable results in these situations.

Muscle vs. Fasciocutaneous Microvascular Free Flaps for Lower Limb Reconstruction: A Meta-Analysis of Comparative Studies

(1) Background: Lower extremity microvascular reconstruction aims at restoring function and preventing infection while ensuring optimal cosmetic outcomes. Muscle (M) or fasciocutaneous (FC) free flaps are alternatively used to treat similar conditions. However, it is unclear whether one option might be considered superior in terms of clinical outcomes. We performed a meta-analysis of studies comparing M and FC flaps to evaluate this issue. (2) Methods: The PRISMA guidelines were followed to perform a systematic search of the English literature. We included all articles comparing M and FC flap reconstructions for lower limb soft tissue defects following trauma, infection, or tumor resection. We considered flap loss, postoperative infection, and donor site morbidity as primary outcomes. Secondary outcomes included minor recipient site complications and the need for revision surgery. (3) Results: A total of 10 articles involving 1340 patients receiving 1346 flaps were retrieved, corresponding to 782 M flaps and 564 FC flaps. The sizes of the studies ranged from 39 to 518 patients. We observed statistically significant differences (p < 0.05) in terms of donor site morbidity and total flap loss with better outcomes for FC free flaps. Moreover, the majority of authors preferred FC flaps because of the greater aesthetic satisfaction and lesser rates of postoperative infection. (4) Conclusion: Our data suggest that both M and FC free flaps are safe and effective options for lower limb reconstruction following trauma, infection, or tumor resection, although FC flaps tend to provide stronger clinical benefits. Further research should include larger randomized studies to confirm these data.

Selecting a free flap for soft tissue coverage in lower extremity reconstruction

BACKGROUND

Goals of lower extremity microvascular reconstruction (LEMR) include the restoration of function, prevention of infection, and optimal cosmesis. Indications for LEMR include large defects that are not amenable to pedicled options, a large zone of injury, and large complex defects. The novice microsurgeon should first master a handful of free flaps to develop an armamentarium of options for addressing such defects. The scope of this review is to provide free flap options for LEMR in any of the thirds of the lower leg. After reading this article, the reader will understand variations, advantages, disadvantages, indications, and tips for raising each of these flaps.

METHODS

Six most commonly used free flaps for LEMR are described in this paper, including the anterolateral thigh flap (ALT) and its variations, the radial forearm flap (RFFF), the lateral arm flap (LAF), the gracilis muscle flap, the rectus abdominis flap (RAF) and the latissimus dorsi flap and its variations. Indications, advantages, disadvantages and technique tips are discussed for each flap. Moreover, selection of the recipient vessels, preoperative management along with an algorithm are also provided.

CONCLUSIONS

The ALT flap is a workhorse in covering defects of the leg, foot, and ankle. It's the flap of choice at our institution, especially given the number of traumatic wounds seen as a result of motor vehicles, all-terrain vehicles (ATV), lawnmowers, and gunshot wounds (GSW). At times, the lower extremity zone of injury requires a distant donor site. The RAF can also provide coverage for large soft tissue defects but donor-site morbidity remains its main drawback. The LAF and RFFF provide two pliable options, one that provides pliable soft tissue with minimal donor site morbidity and another that provides a long pedicle. The free gracilis flap is an excellent choice for crossing the ankle joint. Lastly, the free latissimus dorsi is indicated for large defects of the lower extremity independently of the location.

Comparison of Internal Jugular Vein System Anastomosis and External Jugular Vein System Anastomosis in Free Flaps for Head and Neck Reconstruction: A Meta-Analysis

PURPOSE

The purpose of the present study was to investigate the differences in postoperative thrombosis and flap failure between internal jugular vein (IJV) system anastomosis and external jugular vein (EJV) system anastomosis in free flaps for the reconstruction of head and neck defects.

MATERIALS AND METHODS

We searched PubMed, Web of Science, EMBASE, Chinese BioMedical Literature Database, and other databases until March 2019 for studies that had reported data for anastomosis for the 2 different venous systems in the microvascular free-flap reconstruction of head and neck defects. We assessed thrombosis and flap failure in patients undergoing anastomosis of the IJV system and patients undergoing anastomosis of the EJV system.

RESULTS

Nine studies with a total of 2051 patients with venous anastomosis were included in the present meta-analysis. IJV system anastomosis showed a significantly lower incidence of venous thrombosis than did the EJV system (relative risk [RR], 0.55; 95% confidence interval [CI], 0.37 to 0.82). Eight studies were included in the analysis of the flap failure rate, which showed a lower failure rate for the IJV system anastomosis than for the EJV system (RR, 0.59; 95% CI, 0.35 to 1.00).

CONCLUSIONS

The incidence of thrombosis and flap failure after venous anastomosis in the IJV system was lower than that in the EJV system. The results from the present study have shown that the IJV system should be the first choice for venous anastomosis in the reconstruction of free flaps.

The systematic review and meta-analysis of free flap safety in the elderly patients

BACKGROUND

Prolonged mean life expectancy gives rise to a more populated and older patient group. With increasing number of cases during the past decades, older patients are regarded as candidates for microsurgical interventions. Whether advanced patient age is an independent risk factor for microsurgical reconstruction is still an ongoing matter of debate.

METHODS

The Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, CINAHL and EMBASE databases were screened for combination of the key words "elderly", "geriatric", "advanced age", "free flap", "microsurgery", free tissue transfer" by using time limits between 1989 and 2015.

RESULTS

According to results of the meta-analysis, there was no significant difference in the flap success rates(P =.39, CI = 0.848 to 2.329) and surgical complication rates (P = .83, CI = 0.792 to 1.163) between the young and elderly patient groups. However, the systemic complication rates(P = .02, CI = 1.468 to 3.572), preoperative ASA scores(P < .0001, CI = 0.342 to 1.078), and mortality rates (P = .03, CI = 2.636 to 9.055) were found to be significantly higher in the elderly patients.

CONCLUSIONS

Although an increased rate of systemic complications and mortality has been associated with advanced age, our study results showed no significant difference between the flap success rates and surgical complications. A successful reduction in systemic complications would bring the risk level of reconstructive microsurgical interventions of the elderly patient group to the level of the young patient group. © 2017 Wiley Periodicals, Inc. Microsurgery 37:442-450, 2017.

[Estimation of regional blood flow in reimplanted segments of upper extremity]

AIM

To examine the state of regional circulation in replanted segment of upper limb and hand, to determine diagnostic and prognostic value of radionuclide scintigraphy.

MATERIAL AND METHODS

The study included 26 patients who underwent replantation of upper extremity segments. The control group included 12 patients who underwent autologous transplantation of toes on hand. All patients underwent isotope scintigraphy, ultrasound Doppler and pulse oximetry. Groups were comparable by gender, age, severity of injury.

RESULTS

Depending on postoperative course two groups were determined: with favorable (27 patients) and complicated postoperative period (11 patients). Two types of regional circulation were identified according to dynamic scintigraphy: prevalence of blood flow in operated limb (type 1); prevalence of blood flow in healthy limb, or equal volumetric blood flow in operated and healthy limbs (type 2). Favorable early postoperative period was associated with prevalence of blood flow in operated limb. Only in 2 (7.7%) patients patients in this group acute arterial thrombosis was diagnosed. At the same time thrombosis of microanastomosis occurred in 45.4% of cases in the second group what is 5.5 times higher than in the first group.

CONCLUSION

Significant prevalence of blood flow in operated limb is favorable prognostic sign of the early postoperative period. On the other hand the identity of blood flow or prevalence of such in healthy limb predispose to acute vascular complications in replantate or autoplantate. Radionuclide scintigraphy provides detailed assessment of regional blood flow in operated limb. However clinical monitoring has leading role in diagnosis of acute circulatory disorders in replantate or autoplantate.

Results of free flap reconstruction after ablative surgery in the head and neck

Objectives

Due to the complex anatomy and function of the head and neck region, the reconstruction of ablative defects in this area is challenging. In addition, an increasing interest in improving the quality of life of patients and achieving good functional results has highlighted the importance of free flaps. The aim of this study was to summarize the results of free flap reconstruction and salvage of free flaps in a single institute, and to analyze differences in the results by the flap donor site, recipient site, and learning curve.

Methods

The medical records of patients who underwent free flap reconstruction from 2004-2012 were reviewed retrospectively. One hundred and fifty free flaps were used in 134 patients, who had an average age of 57.7 years. The types of flaps applied, primary defect sites, success rates, results of salvage operations for compromised flap, and the learning curve were analyzed.

Results

The anterolateral thigh flap was preferred for the reconstruction of head and neck defects. The overall success rate was 90.7%, with 14 cases of failure. A total of 19 salvage operations (12.7%) for compromised flap were performed, and 12 flaps (63.2%) were salvaged successfully. Dependency on the facial vessels as recipient vessels was statistically different when oral and oropharyngeal defects were compared to hypopharyngeal and laryngeal defects. The learning curve for microvascular surgery showed decrease in the failure rate after 50 cases.

Conclusion

The free flap technique is safe but involves a significant learning period and requires careful postoperative monitoring of the patient. Early intervention is important for the salvage of free flaps and for lowering the failure rate.

Catastrophic Outcomes in Free Tissue Transfer: A Six-Year Review of the NSQIP Database

Background. No studies report robust data on the national incidence and risk factors associated with catastrophic medical outcomes following free tissue transfer. Methods. The American College of Surgeons (ACS) multicenter, prospective National Surgical Quality Improvement Program (NSQIP) database was used to identify patients who underwent free tissue transfer between 2006 and 2011. Multivariable logistic regression was used for statistical analysis. Results. Over the 6-year study period 2,349 patients in the NSQIP database underwent a free tissue transfer procedure. One hundred and twenty-two patients had at least one catastrophic medical outcome (5.2%). These 122 patients had 151 catastrophic medical outcomes, including 93 postoperative respiratory failure events (4.0%), 14 pulmonary emboli (0.6%), 13 septic shock events (0.5%), 12 myocardial infarctions (0.5%), 6 cardiac arrests (0.3%), 4 strokes (0.2%), 1 coma (0.0%), and 8 deaths (0.3%). Total length of hospital stay was on average 14.7 days longer for patients who suffered a catastrophic medical complication (P < 0.001). Independent risk factors were identified. Conclusions. Free tissue transfer is a proven and safe technique. Catastrophic medical complications were infrequent but added significantly to length of hospital stay and patient morbidity.

The outcome of free tissue transfers in patients with hematological diseases: 20-year experiences in single microsurgical center

BACKGROUND

Free tissue transfers performed in patients with hematological diseases represent significant challenges for micro-surgeons. There are rare literatures that address the outcome in these patients. Therefore, we collected our database, analyzed the outcome, reliability, and related-management of microsurgical technique in the patients with hematological diseases.

METHODS

A retrospective chart review of 20 patients with hematological disorders who received free tissue transfers during 20-years period in a single microsurgical center was done. Eleven patients who received head and neck reconstruction were found to have hyperfibrinogenemia. Seven patients with reactive thrombocytosis after trauma, and two patients with leukemia had soft tissue defects in the upper and lower extremities. Twenty-six flaps were used for free tissue transfers. Intra-operatively all patients received intravenous 5,000 Ud of heparin post immediate reperfusion. Anti-coagulant medication such as Dextran-40 or prostaglandin-E1 (PGE1) was given postoperatively.

RESULTS

Twenty-three of the 26 free flaps survived without vascular compromise. Intra-operatively all patients received intravenous 5,000 Ud of heparin post immediate reperfusion, and anti-coagulant medication such as Dextran-40 or prostaglandin-E1 was given to the patients postoperatively. The three failed cases were found in patients with hyperfibrinogenemia and needed further reconstruction with another flap. The overall success rate was 88.5% (23/26).

CONCLUSIONS

Hematologic disorder is not a predicted factor of free flap failure. The key factors for success flap survival in patients with hematologic disorders include preoperative knowledge of the medical condition and monitoring potential post-operative complications, aggressive hematologist consultations, and meticulous non-traumatic surgical anastomosis.

Microvascular free-flap transfer for head and neck reconstruction in elderly patients

Background

With the increase in life expectancy, the incidence of head and neck cancer has grown in the elderly population. Free tissue transfer has become the first choice, among all the reconstructive techniques, in these cases. The safety and success of micro vascular transfer have been well documented in the general population, but its positive results achieved in elderly patients have received less attention.

Methods

We retrospectively studied 28 patients over the age of 60 years. The aim of this paper was to study the success rate of free tissue transfer and investigate the complication incidence in this patient population.

Results

Twenty-eight free flaps were performed to reconstruct medium to large cervico-facial surgical defects in six years. No difference was noted between success and complication rates observed between general and elderly population.

Conclusion

This study indicates that free-flap technique for head and neck reconstruction could be considered a safe option in elderly patients when a good pre-operative general status is present.

The impacts of liver cirrhosis on head and neck cancer patients undergoing microsurgical free tissue transfer: an evaluation of flap outcome and flap-related complications

Several authors have cited liver cirrhosis as a risk factor for surgery but no study performed statistical correlation between flap outcome and severity of liver cirrhosis in patients with head and neck cancer. We performed a retrospective analysis of 3108 patients who underwent free tissue transfer after head and neck cancer ablation between January 2000 and December 2008. Liver cirrhosis was identified in 62 patients. Forty-two patients (67.7%) were classified as having Child's class A cirrhosis, seventeen (27.4%) as having class B, and three (4.9%) as having class C cirrhosis. The overall complete flap survival rate was 90.3% (56/62). The flap-related complications of patients with Child's class A, B, and C were 38.1% (16/42), 47.1% (8/17), and 100% (3/3), respectively and showed no significant difference between these three groups (p=0.2758). The rate of postoperative neck hematoma was 14.5%; the risk of postoperative neck hematoma was significantly higher in patients with more advanced liver cirrhosis (p=0.0003). The recipient-site complications of patients with Child's class A cirrhosis, Child's class B, and Child's class C cirrhosis were 35.7%, 41.1%, and 66.6%, respectively, with no significant difference among the three groups. The statistical analysis demonstrated that diabetes mellitus is significantly associated with a negative prognosis for free flap reconstruction (p=0.0364). The flap survival rate and patency of microvascular anastomosis have no association with liver cirrhosis. To achieve a superior surgical outcome, preoperative optimization and a multidisciplinary team responsible for the evaluation and treatment of head and neck cancer patients with cirrhosis are necessary.

Analysis of salvage treatments following the failure of free flap transfer caused by vascular thrombosis in reconstruction for head and neck cancer

BACKGROUND

Few authors have reported the subsequent treatment for patients in whom free tissue transfers in the head and neck have failed as a result of vascular thrombosis.

METHODS

Between 1993 and May of 2005, 502 free flaps were transferred after head and neck cancer ablation in the authors' hospital, 19 of which resulted in total necrosis caused by vascular thrombosis. The authors categorized these 19 cases into four groups and analyzed the salvage treatment.

RESULTS

For failed free jejunal transfer, early initiation of oral intake was obtained when another free jejunum was transferred. For failed free soft-tissue transfer for intraoral defects, reconstruction with common free (first choice) or pedicled flaps was used: a voluminous musculocutaneous flap for extensive defects, forearm flap or pedicled pectoralis major flap for intermediate defects, and direct closure for small defects of the oral floor. For failed secondary soft-tissue transfer to improve a certain function, salvage flap transfer was not chosen in the acute setting. For failed secondary maxillary reconstruction, simple reconstruction using the rectus abdominis musculocutaneous flap combined with costal cartilage achieved stable results. The overall success rate of the repeated free flap was 89 percent (eight of nine patients).

CONCLUSIONS

When a free flap is judged unsalvageable, surgeons should determine subsequent treatments, considering the success rate as one of the most important factors. The authors believe that simple reconstruction using a common free flap is the first choice in most cases. When regional or general conditions do not permit further free flap transfer or when defects are comparatively small, reconstruction with a pedicled flap or direct closure of the defect may be considered.

Timing of Presentation of the First Signs of Vascular Compromise Dictates the Salvage Outcome of Free Flap Transfers

BACKGROUND

Microsurgical free tissue transfer has become a reliable technique. Nevertheless, 5 to 25 percent of transferred flaps require re-exploration due to circulatory compromise. This study was conducted to evaluate the timing of occurrence of flap compromise following free tissue transfer, and its correlation with salvage outcome.

METHODS

Between January of 2002 and June of 2003, 1142 free flap procedures were performed and 113 flaps (9.9 percent) received re-exploration due to compromise. All patients were cared for in the microsurgical intensive care unit for 5 days. Through a retrospective review, timing of presentation of compromise was identified and correlated with salvage outcome.

RESULTS

Seventy-two flaps (63.7 percent) were completely salvaged and 23 (20.4 percent) were partially salvaged. Eighteen flaps (15.9 percent) failed completely. Ninety-three flaps (82.3 percent) presented with circulatory compromise within 24 hours; 108 (95.6 percent) presented with circulatory compromise within 72 hours, and 92 flaps (85.2 percent) were salvaged within this period. One out of the three flaps presenting with compromise 1 week postoperatively was salvaged. Flaps presenting with compromise upon admission to the microsurgical intensive care unit had significantly lower complete salvage rates as compared with those without immediate abnormal signs (40.9 percent versus 69.2 percent, p = 0.01).

CONCLUSIONS

The time of presentation of flap compromise is a significant predictor of flap salvage outcome. Intensive flap monitoring at a special microsurgical intensive care unit by well-trained nurses and surgeons allows for early detection of vascular compromise, which leads to better outcomes.

Microvascular breast reconstruction pedicle thrombosis: How long can we wait?

Re-exploration plays a key role in salvaging vascularly compromised free flaps. A retrospective review of 290 free flaps in breast reconstruction was performed to determine whether the time delay between thrombosis detection and surgical re-exploration had any effect on flap salvage. Overall flap success was 97.6%. Postoperative thrombosis requiring re-exploration was documented in 6.2% cases. Fifty-five percent of take-back flaps were salvaged and 45% were lost. The median time between detection of flap compromise to surgical incision was 128 min in our saved flaps, and 228 min in the lost flap group. Our preliminary data suggests that re-exploration within 188 min may improve flap salvage.

Microvascular free tissue transfer in patients with hematological disorders

BACKGROUND

Microsurgical procedures performed in patients with hematological disorders can pose significant challenges. The literature is lacking in reports that specifically address the safety, reliability, and management techniques related to performing microvascular surgery in this group of patients.

METHODS

A retrospective chart review of all patients with hematological disorders who received free flaps from 1995 to 2004 was performed. All patients had a hematologic work-up that confirmed the stability of the underlying disease. There were three male and three female patients with an average age of 27.6 years (range,12 to 63 years). Patients had leukemia (n = 2), hereditary spherocytosis, non-Hodgkin's lymphoma, and hemophilia (n = 2). Their defects were in the areas of the nasocolumella/upper lip, palate, palate and midface, and lower extremities.

RESULTS

All patients received free flaps and all but one had an uneventful postoperative course. That patient, with hemophilia, 1 day after factor replacement was halted, had bleeding that required surgical re-exploration along with aggressive hematologic management. All flaps survived without vascular compromise. No wound infections were observed. All donor sites healed without complications.

CONCLUSIONS

Essential ingredients in the treatment plan of patients with hematologic disorders undergoing free flaps include familiarity with the preoperative medical condition and potential postoperative complications, close monitoring of the patients and their medical condition before and after surgery, meticulous surgical technique, and close cooperation with the hematologists and infectious disease specialists. By following this regimen, patients with hematologic disorders and an otherwise stable medical history can undergo free tissue transfer safely and effectively with reliable outcomes.

Guidelines for the optimization of microsurgery in atherosclerotic patients

We review the pathogenesis of atherosclerosis and the issues that must be taken into consideration when performing microsurgery in atherosclerotic patients. Atherosclerosis is a systemic disease, and may affect the success of microsurgery. Atherosclerotic patients have a tendency toward thrombosis, because the nature of the arteries is changed. Such patients are usually old and have additional medical problems. To increase the success rate of microsurgery in atherosclerotic patients, special precautions should be considered. Patients must be evaluated properly for the suitability of microsurgery. The microsurgical technique requires a meticulous approach, and various technical tricks can be used to avoid thrombosis. Recipient-vessel selection, anastomotic technique, and the use of vein grafts are all important issues. Prophylactic anticoagulation is recommended in severely atherosclerotic patients. Close monitoring of the patient and flap is necessary after the operation, as with routine microvascular free-tissue transfers. We conclude that atherosclerosis is not a contraindication for microsurgery. If the microsurgeon knows how to deal with the difficulties in atherosclerotic patients, microsurgery can be performed safely.

The Safety of Microvascular Free Tissue Transfer in the Elderly Population

The objective of this study was to evaluate the safety and thus the efficacy of microvascular free tissue transfer in the elderly patient population. Free flaps for different types of reconstructions were analyzed to verify whether free tissue transfer is feasible in the elderly. Between 1993 and 2003, 102 free flaps were performed in 94 patients who were aged 70 years or older. There were 75 male and 19 female patients, with a mean age of 73.8 years (range, 70 to 87 years). Different types of free flaps were performed for head and neck (n = 78), lower extremity (n = 12), and trunk and upper extremity (n = 4) reconstruction. Nine flaps underwent reexploration and four of them were lost, for an overall success rate of 96 percent. Medical complications in the postoperative period were further evaluated. A total of 32 medical complications were seen in 29 patients. Only one patient died because of postoperative complications. The frequency of medical complications was further analyzed in detail. Effects of American Society of Anesthesiologists status, operation time, and age on complication rate were evaluated statistically. Only American Society of Anesthesiologists status was statistically significant for the occurrence of postoperative medical complications; class III and IV patients were at higher risk than class I and II. Neither operation time nor age was predictive of postoperative complications. Microvascular free tissue transfer is a safe and reliable option in the elderly population. The success rate of free flaps is not different from that for other age groups. The rate of postoperative medical complications was 31 percent (29 of 94 patients); most complications were in American Society of Anesthesiologists class III and IV patients.

Experiences with microsurgical tissue transfers in elderly patients

The combination of advances in microsurgery and the improvement of anesthetic management with increased understanding of the physiology of preoperative and postoperative care has significantly raised the upper age limit for free-flap transfer in elderly patients. Despite pessimistic opinions regarding elderly patients who have poor recovery potential and decreased physiological reserves, the unique feature of free-tissue transfer is that it allows the transfer of well-vascularized tissue to defects in a single-stage procedure, and leads to improved quality of life. In this report, a retrospective analysis of 55 patients aged 50 and older who underwent microsurgical tissue transfer is presented. Hospital and our own records were used to review various parameters. The preoperative medical status of each patient was assessed using the American Society of Anesthesiologists (ASA) Classification of Physical Status. Each patient's preoperative medical records, age, sex, transferred tissue type, and length of operation were outlined. Postoperative recorded parameters were the fate of flaps and the short-term postoperative outcome, including surgical complications, medical morbidity, and death within 30 days of surgery. Fifty-eight microvascular tissue transfers were performed in 55 consecutive patients. The study comprised 38 male and 17 female patients, with a mean age of 64.8 years. ASA classification status was class 1 for 15 patients, class 2 for 26 patients, and class 3 for 14 patients. Twenty-five flaps were used for lower extremity reconstruction, 32 flaps were used for head and neck reconstruction, and 1 was used for breast reconstruction. The average operative time was 5.7 h, ranging between 2-13 h. There were 14 major medical complications, resulting in an overall medical complication rate of 25%. There were 3 deaths within 30 days postoperatively. Thus, the overall surgical mortality rate was 5.4%. The longer operation times were associated with the development of postoperative total medical and surgical complications (P = 0.008). While the relationship between ASA class and medical complications was significant (P = 0.0007), no significant relation was determined between ASA class and surgical complications (P = 0.66). It was revealed that the greater the age group, the greater the occurrence of postoperative medical complications (P = 0.0001). The relationship between postoperative surgical complications and age groups was not significant (P = 0.07). It was also demonstrated that the advanced age of patients was associated with a higher ASA class (P = 0.0017). Eleven flaps required reoperation for vascular compromise. While 10 of these were salvaged with vascular anastomosis revisions, one flap was lost. Thus the overall flap success rate was 98.3%. In conclusion, if a patient's medical problems do not constitute a handicap, age itself should not be considered a barrier to free-flap transfer. It is important to be familiar with preoperative medical problems and possible postoperative medical complications in order to achieve a successful outcome. Contrary to what is generally suggested, surgical complications do not constitute a special consideration in older patients.

Salvage of free flaps after venous thrombosis: Case report

Venous thrombosis of a free flap is a serious complication in microsurgery. Several agents with the ability to dissolve an occluding thrombus exist. Recombinant tissue plasminogen activator (rt-PA) seems the most effective. We present our experience with a procedure that was successful in elimination of the occluding thrombus in two patients.

Pressure-specifying Sensory Device: Quantitative Sensory Measurement in the Oral Cavity and Oropharynx of Normal Adults

We conducted a study to quantitatively determine the pressure perception thresholds in the oral cavity and oropharynx of a normal population with the Pressure-Specifying Sensory Device (PSSD). The PSSD measured pressure perception thresholds for both static and moving one- and two-point discrimination modalities at a variety of sites in the oral cavity and oropharynx as well as in the forearm of 11 adults. We also evaluated the ability of the PSSD to enhance sensory discrimination in four of these subjects by the process of sensory re-education for 11 days over a 15-day period. We found that the buccal mucosa and the tongue tip were the most sensitive sites in the oral cavity and oropharynx and that the floor of the mouth and the soft palate were the least sensitive. Sensory discrimination in the oral cavity was enhanced in all four subjects who underwent sensory re-education, although it returned to baseline levels over time after re-education was discontinued. The degree of intra- and intertester variability was minimal. Our data can be used as an aid in the development of techniques to surgically restore sensation in the oral cavity and oropharynx.

Management of flaps with compromised venous outflow in head and neck microsurgical reconstruction

Microvascular tissue transfer has become an indispensable procedure for head and neck reconstruction. Although remarkable progress has been made technically, anastomosed vessel occlusion is still a serious complication. Even with technically skilled microsurgeons, anastomosed vessel occlusion occurs because the technique is not the sole prophylaxis against thrombosis in microsurgery. Therefore, to minimize the possibility of an unfavorable result in microsurgery, microsurgeons must be familiar with management options for a vascular compromised flap. Most investigators have agreed that venous obstruction occurs more often than arterial obstruction. Here, we reviewed the published literature on the salvage of venous compromised flaps from the viewpoints of surgical correction, including reanastomosis and catheter thrombectomy, and nonsurgical procedures, such as a medicinal leech, hyperbaric oxygen, and thrombolytic therapy.

Factors that influence the outcome of salvage in free tissue transfer

INTRODUCTION

The success of salvage techniques for free tissue transfer is well documented. The aim of this study was to identify factors that influenced the results of salvage operations in a group of patients who required early exploration.

METHODS

From a database survey of 408 patients who had a total of 427 free tissue transfer reconstructions, 65 (16%) returned to the operating theatre within 7 days. A retrospective analysis of their progress was made from the case records.

RESULTS

The flap chart was found to be highly accurate for the 65 patients who had returned to the operating theatre, reporting two false positives and one false negative. Forty patients had compromised flaps and 25 had haematomas that required evacuation. The commonest problem with flaps was venous congestion (33/40, 83%), and 29 flaps were successfully salvaged (73%). Most successful salvage attempts were made within 24 hours of the end of the initial operation. The salvage rate was higher for the radial fasciocutaneous flaps (25/30, 83%), than for composite flaps (2/7, 29%). A total of 24/427 flaps failed (6%).

CONCLUSIONS

We now recommend hourly observations of the flap for 24 hours followed by 4-hourly monitoring for 48 hours. Improved monitoring techniques for composite grafts may result in more being salvaged and a better overall survival.

Microsurgical repair after crush-avulsion injury of the femoral vein in rats: prevention of microvascular thrombosis with recombinant human tissue-type plasminogen activator (rt-PA)

Vein thrombosis is often encountered in microsurgery, especially in the case of crush-avulsion injuries. The aim of this study was to investigate the effect of systemic administration of recombinant tissue-type plasminogen activator (rt-PA) on the patency of the femoral vein of the rat, which had previously sustained a crush-avulsion injury. The study consisted of 3 groups of male Wistar rats, 20 animals each. A standardized crush-avulsion injury model was used. After microvascular repair of the femoral vein, the animals received either normal saline (group A), heparin 100 U/kg body weight (group B), or rt-PA 3.5 mg/kg body weight (group C) systemically. Patency tests were performed at 20 minutes, 48 hours, and 1 week after blood flow reestablishment. According to our results, the patency rate of the rt-PA group was significantly higher than in both the control and heparin groups.

The effect of twisting on microanastomotic patency of arteries and veins in a rat model

The authors examined the effect of twisting on the patency of microvascular anastomoses 3 days after surgery. A total of 69 male Wistar rats were divided randomly into four groups. The femoral arteries and veins were dissected for a standard distance. A total of 69 microarteriorrhaphies and 68 microvenorrhaphies were performed at 0 deg and with twist of the vessel ends of 90, 180, and 270 deg. Three-day patency rates for arterial microanastomoses were 100% with a 0-deg twist, 80.9% with a 90-deg twist, 68.4% with a 180-deg twist, and 64.2% with a 270-deg twist. Three-day patency rates for venous microanastomoses were 100% with a 0-deg twist, 85% with a 90-deg twist, 28.5% with a 180-deg twist, and 25% with a 270-deg twist (p = 0.047 for arteries, p = 0.001 for veins). These data are statistically significant. Moreover, assuming the risk of thrombosis to be 1 for microanastomosis without twisting, the odds ratio for the risk of vessel thrombosis for 270-deg twisting (the maximal examined degree of arterial and venous twist in the current study) is 10.08 for arterial anastomosis and 226.85 for venous anastomosis.

External venous shunt as a solution to venous thrombosis in microvascular surgery

We report a case in which venous occlusion occurred after fibular osteocutaneous flap transfer for open tibial fracture. The flap was salvaged using an external venous shunt. The shunt consisted of a Teflon catheter for intravenous infusion, a three-way stopcock, a urokinase-immobilised catheter and a pressurising bag for arterial-pressure monitoring. This method can be used to establish venous drainage when there is no accessible recipient vein. It may improve the success rate of microvascular surgery and extend the indications for surgery.

Challenging the limits: build your own reliable double microvascular clamps

This report describes the detailed construction, experimental basis, and clinical application of a reliable double microvascular clamp that can be built from inexpensive parts that are readily available. Twenty-five clinical free-tissue transfers were performed using this clamp with an acceptable free-flap survival rate.

Parameters for the preoperative evaluation of arteriosclerosis for free-flap transfers in head and neck surgery

The microsurgical transfer of free tissue has become essential for reconstructive surgery in the head and neck, and arteriosclerosis is one of the risk factors for microvascular anastomosis. In order to detect severe arteriosclerosis and to determine the parameters useful for evaluating arteriosclerosis preoperatively, the grade of arteriosclerosis was investigated with respect to age, PWV (Aortic Pulse Wave Velocity), ocular fundus findings, and histopathological findings of the recipient arteries in 40 patients with malignant tumours. Severe arteriosclerosis was detected in 2/40 patients by the PWV, in the same 2/40 patients by the ocular fundus findings and in the same 2/40 patients by histopathological findings. The current observations indicate that the PWV and ocular fundus findings are useful parameters for the preoperative evaluation of the grade of arteriosclerosis.

Local recombinant tissue plasminogen activator (rt-PA) thrombolytic therapy in microvascular surgery

Vascular thrombosis remains a dreaded complication of any microvascular procedure, be it composite tissue transfer or replantation of amputated limbs or parts. Despite the tremendous advances in microvascular-related technologies and the accumulated surgical skills, failures caused by occlusion of anastomosed vessels remain a continuous source of frustration to all microsurgeons alike. Several anticoagulation and antiplatelet protocols have been proposed to be used in conjunction with microvascular surgery. More recently, thrombolytic drugs such as urokinase, streptokinase, and thrombolysin have been introduced, yet their systemic effect on hemostasis remains an undesirable side effect. We present our experience with local intra-arterial, intravenous, and soft-tissue injection of recombinant tissue plasminogen activator rt-PA in replantation surgery in three consecutive patients. Arterial thrombi are managed by intra-arterial rt-PA infusion with the catheter placed proximal to the arterial anastomosis. Venous thrombi are best lysed by infusing rt-PA in an engorged vein of the replanted limb. In replanted digits, direct intravenous infusion is not possible. In such situations, injection of rt-PA in the pulp soft tissues may result in successful salvage. We believe this agent also has a role in microvascular composite tissue transfer in preventing free flap failures as well as in salvaging failing flaps.

Bilateral breast reconstruction in very thin patients with extended free TRAM flaps

A lateral extension of the free TRAM flap design is described for use in unusually thin patients who desire bilateral autologous tissue breast reconstruction. Because of the exceptionally good blood supply to the free TRAM flap, the lateral extensions are viable even when the flap is folded double to increase its thickness and projection. To increase the volume of the reconstructed breast, the flaps can be extended as far laterally as the surface of the operating table will permit. With this approach, bilateral TRAM flap breast reconstruction is possible even for extremely thin patients.

Complications after microsurgical tissue transfer in the head and neck region

In recent years, the use of microsurgically re-anastomosed free transplants has become a proven technique for the reconstruction of defects in the head and neck region, which is demanding from both aesthetic and functional points of view. A retrospective catamnestic study on 227 free tissue transfers in the Department for Oral and Maxillofacial Surgery at the University of Tübingen showed good healing with relatively low failure rates of the transplants used. A significant proportion of local complications, arising postoperatively, was to some degree due to pre-existing medical conditions, tumour-specific pretreatments and the particular wound-healing situation found in head and neck interventions. The highest relative rate of complications at the site of origin was seen amongst osteomuscular transplants (20%) whilst (fascio) cutaneous and visceral transplants were found to result in a low percentage of problems (4%). In contrast, the healing of iliac crest transplants was accompanied by various local complications in 12% of the cases, slightly higher than 20% amongst (fascio) cutaneous and abdominal transplants and well above 30% for latissimusdorsi and scapular transplants. General complications, in particular of a respiratory and/or psychiatric nature, were found in 23% of the patients.

The effect of twist on microvascular anastomotic patency and angiographic luminal dimensions

BACKGROUND

Microvascular anastomoses must be constructed perfectly in order to be successful. One of the subtle technical errors that can occur during construction is twisting of the anastomosis. In the present study, we examined the effect of twist on the immediate, 2-h postoperative angiographic dimensions and patency of microvascular anastomoses.

MATERIALS AND METHODS

Sixty-four Sprague-Dawley rats were assigned randomly to four groups. The femoral arteries were dissected for a distance sufficient to permit the application of an 8.5-mm-long microanastomotic approximator clamp. Microarteriorrhaphies were performed with twists of 0 degrees, 90 degrees, 180 degrees, or 270 degrees. Patency was assessed 2 h after surgery using transabdominal aortic arteriography with run-off. Measurements were recorded for each anastomosis, as well as for the narrowest and widest diameters of the vessels within 10 mm of the anastomosis.

RESULTS

Fifty-nine of the 64 rats had technically satisfactory angiograms which permitted measurement of vascular dimensions. The cross-sectional areas of the narrowest areas and the anastomoses were inversely related to the degree of twist, and were significantly reduced at 270 degrees (P < 0.05). Two-hour patency rates were 86% with 0 degrees twist, 82% with 90 degrees twist, 71% with 180 degrees twist, and 33% with 270 degrees twist. The reduction in patency with 270 degrees twist was statistically significant (P < 0.05).

CONCLUSIONS

Twists of 0 degrees, 90 degrees, and 180 degrees did not impair patency at a statistically significant level, but twists of 270 degrees did significantly reduce patency of microvascular anastomoses (P < 0.05).

Ischemic preconditioning improves the survival of skin and myocutaneous flaps in a rat model

Inadequate blood supply of pedicle flaps results in partial necrosis, and prolonged ischemia during free-tissue transfer can result in partial or complete flap necrosis. Recent research in the field of cardiovascular surgery has shown that ischemic preconditioning (repeated brief episodes of coronary artery occlusion followed by reperfusion) improves myocardial muscle survival when the heart is subsequently subjected to prolonged ischemia. Preconditioning of skin or myocutaneous flaps as either pedicle or free flap models has never been studied. The goal of this investigation was to measure the effect of ischemic preconditioning on myocutaneous and skin flap survival areas and total necrosis rates after variable periods of global ischemia. In 220 rats, 100 transverse rectus abdominis myocutaneous flaps and 120 dorsal cutaneous flaps were randomized into treatment and control groups. The treatment flaps underwent preconditioning by three cycles of 10 minutes of pedicle clamping followed by 10 minutes of reperfusion for a total preconditioning period of 1 hour. The control flaps were perfused without clamping for 1 hour. Both control and treatment flaps then underwent global ischemia for 0, 2, 4, 6, 10, or 14 hours by pedicle clamping. Flap survival area was measured on the fifth postoperative day. Statistical analysis was performed with analysis of variance, student's t tests, and probit analysis. Preconditioning improved survival areas of pedicle myocutaneous flaps (0-hour group) from 47 +/- 16 percent (mean percent area surviving +/- SD) to 63 +/- 5 percent. This difference was statistically significant (t test, p < 0.04). There was no statistically significant improvement in pedicle skin flap survival. For free flap models (flaps undergoing global ischemia), preconditioning increased the survival areas of skin and myocutaneous flaps (analysis of variance, p < 10(-5)). For the skin flap model, statistical significance of the survival area difference was reached at 6, 10, and 14 hours of ischemia (t test, p < 10(-4)). The magnitude of this effect was higher in the myocutaneous flap model and reached statistical significance at 2, 4, 6, and 10 hours of ischemia (p < 10(-3)). Preconditioned flap survival areas were increased by two to five times that of non-preconditioned flaps at these ischemia times. Preconditioning lowered total necrosis rates at all ischemia times for both flap models. The critical ischemia time when 50 percent of skin flaps became totally necrotic (CIT50) improved from 6.9 to 12.4 hours by preconditioning. Similarly, preconditioning improved the CIT50 of myocutaneous flaps from 3.6 to 9.2 hours. For the first time, statistically significant improvements of partial necrosis areas and total necrosis rates have been demonstrated through intraoperative ischemic preconditioning of skin and myocutaneous flaps. In clinical practice, application of this technique may lead to improved survival during pedicled or free transfer of myocutaneous flaps and free transfer of skin flaps.

Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction

BACKGROUND

The incidence of internal jugular vein thrombosis (IJVT) following a modified neck dissection remains uncertain. The effect of, or consequences following, IJVT upon pedicled and free flap head and neck reconstructions remains unexplored.

METHODS

Twenty-nine preserved internal jugular veins in 24 patients undergoing modified neck dissection were available for prospective study. All patients required a pedicled or free flap reconstruction and received a modified, unilateral or bilateral cervical lymphadenectomy. The patency of all jugular veins was determined preoperatively and postoperatively using a combination of computed tomography (CT) scanning, high-resolution ultrasound, and color-flow Doppler (CFD).

RESULTS

The IJVT rate was 14%. The presence of a pedicled myocutaneous flap and left-sided jugular dissections may represent risks to the postoperative patency of the internal jugular vein. Preoperative radiotherapy did not appear to impact negatively upon the thrombosis rate.

CONCLUSIONS

Thrombosis of the internal jugular vein may result in significant morbidity for the postoperative oncologic patient. An internal jugular-dependent-free-tissue transfer may risk venous compromise of the flap, whereas the use of a pedicled flap may place the jugular at increased risk for thrombosis. Strategies for deep venous system microvascular recipient recruitment in the head and neck are discussed. Wherever possible, we employ two deep venous systems, the internal jugular, and subclavian (via the external jugular) for flap drainage.

Effects of extradural anesthesia on microcirculatory blood flow in free latissimus dorsi musculocutaneous flaps in pigs

Free musculocutaneous flaps are used frequently in plastic surgery to reconstruct soft-tissue defects after radical cancer surgery and trauma. Despite improved surgical techniques, some of these flaps fail due to insufficient blood supply. Extradural anesthesia causes both sensory (pain relief) and sympathetic (vasodilatation) block that may be advantageous in free-flap surgery. This hypothesis, however, has not yet been studied. An experimental model in pigs was developed in which clinical conditions for anesthesia and microvascular surgery on the lower extremity were simulated as closely as possible. The effects of extradural anesthesia as well as phenylephrine infusion, combined with general anesthesia, on central hemodynamics and on microcirculatory blood flow in skin and muscle of the latissimus dorsi free flap were studied. After surgery, seven animals received extradural anesthesia during stable normovolemic conditions and another seven during mild hypovolemia (10 percent blood loss). The extradural block was objectively evaluated using the temporal summation test. Thirty minutes after induction of extradural anesthesia, the animals received an intravenous infusion of phenylephrine 1 microgram/kg per minute over a period of 15 minutes. Multichannel laser-Doppler flowmetry was used to measure microcirculatory blood flow in skin and muscle of the free flap as well as in control skin and muscle on the same extremity simultaneously. In normovolemic animals, extradural block caused a 10 percent decrease in mean arterial pressure and cardiac output and an approximately 20 percent decrease in microcirculatory blood flow in both the skin and muscle of the flap (all changes were nonsignificant). In slightly hypovolemic animals, however, extradural anesthesia caused a significant decrease in cardiac output (31 percent, p < 0.01), mean arterial pressure (24 percent, p < 0.01), and in mean blood flow in the flap muscle (22 percent, p < 0.05) and skin (20 percent, p < 0.05). During phenylephrine infusion, mean arterial pressure increased significantly (p < 0.05) in both hypovolemic and normovolemic animals, while cardiac output and microcirculatory blood flow in the flap remained almost unchanged. Extradural anesthesia does not improve microcirculatory blood flow in free musculocutaneous flaps in pigs. It causes a significant decrease in cardiac output, mean arterial pressure, and microcirculatory blood flow in slightly hypovolemic animals. During phenylephrine infusion, the microcirculatory blood flow in free flaps slightly improves due to the increase in mean arterial pressure. We suggest that extradural anesthesia for microvascular surgery should be used with great caution until human data are available.