Ross DA, Ariyan S, Restifo R, Sasaki CT. Use of the Operating Microscope and Loupes for Head and Neck Free Microvascular Tissue TransferA Retrospective Comparison. Arch Otolaryngol Head Neck Surg. 2003;129(2):189-193. doi:10.1001/archotol.129.2.189
To analyze whether less cumbersome loupes are as equally efficacious as the microscope for magnification for free tissue transfers in head and neck reconstruction.
A 7-year retrospective review of 151 consecutive microvascular free tissue transfers compares the operating microscope with loupe magnification.
A tertiary care medical center.
A total of 151 consecutive patients undergoing microvascular reconstructions.
Microvascular reconstruction of ablative head and neck cancer defects using either microscopic or loupe-provided magnification.
Main Outcome Measures
Medical records were reviewed for demographic data, preoperative radiation status, type of defect and flap, length of procedure, complications, and length of stay.
Two teams shared the reconstructions, with all microvascular anastomoses created or directly supervised by one of us (D.A.R.). One team used the operating microscope for magnification (84 cases), while the other used loupes (67 cases). Complication rates were statistically similar for the 2 techniques, the length of procedure tended to be shorter in the loupe group, and the length of stay was statistically similar in both groups.
A review of the literature validates the usefulness of loupe magnification in free tissue transfer surgery. To our knowledge, this is the largest number of head and neck reconstruction cases presented comparing these techniques. Loupes offer the surgeon comfort and easy access to and uncomplicated visualization of the operating field. Furthermore, loupes may decrease operating time and help avoid complicated equipment. Therefore, loupe magnification should be considered in head and neck reconstruction without the fear of increased morbidity.
MICROVASCULAR free tissue transfers (FTTs) have become an important method of reconstruction following oncologic resections in the head and neck. Failure of such reconstructions can often lead to life-threatening wound breakdown and fistulas. The operating microscope has been widely used to ensure the patency of microvascular anastomoses, particularly when manipulating vessels smaller than 3 mm.1,2 Although magnification is necessary when creating anastomoses, the operating microscope can be quite cumbersome, often requiring the patient, surgeon, or assistant surgeon to be in awkward positions when performing the intricate repairs.
Operating loupes have always played an important role in head and neck FTT reconstructions. They are used frequently in the harvesting of the flap from its donor site. The loupes provide excellent magnification (×2.5 to ×6.5) and are much less awkward than an unwieldy machine. Historically, loupes were assumed to be less effective than the microscope when creating the actual microvascular anastomoses. Yet, reports in other publications have indicated the effective use of loupe magnification when repairing peripheral nerves3 or reversing sterilization.4 Inevitably, some surgeons attempted to use loupe magnification for microvascular anastomoses and reported successful results.5- 7
One of us (S.A.) had stopped using the microscope and turned to operating loupes in 1981 for free flaps and replants because of the ease of use. This provided us with the perfect opportunity to compare the results of the 2 techniques.
For the past 7 years, we have been creating anastomoses with either a surgical microscope or loupe magnification. We reviewed a total of 151 FTTs in the head and neck, 67 of which were performed with loupe magnification for the creation of microanastomoses; to our knowledge, this is the largest series to date.
A 7-year retrospective review, from December 1993 to December 2000, was undertaken of 151 consecutive FTTs performed at the Yale–New Haven Medical Center. These patients were deemed not appropriate candidates for myocutaneous flap reconstructions. A computer-generated list of cases was obtained from the hospital's medical records department. Medical records were then evaluated, and relevant data were extracted and filed into a computer spreadsheet program. Relevant data were collected, including patient's age and sex, tumor site, history of previous radiation therapy, type of free flap, complications, length of procedure, length of stay (LOS), and type of magnification used for the creation of microanastomoses.
An ablative team (lead by C.T.S.), a reconstruction team (D.A.R., S.A., and R.R.), and, when necessary, a radiation oncology team performed intraoperative brachytherapy implantation. The ablative team would normally complete their work before the reconstructive team began, allowing the microvascular surgeons to know exactly the extent of the defect. However, overall surgical time increases when the donor flap is not harvested during the ablative procedure.
All reconstructive and microanastomotic procedures were performed with the same lead surgeon (D.A.R.); however, the cosurgeon determined whether the microscope (R.R.) or loupes (S.A.) were used for the microanastomoses. Of the 151 total reconstructions, the microscope was used in 84 and loupes were used in 67. The ratio of loupes-microscope cases did not vary during the 7 years: 1.25 microscope-aided reconstructions to every 1 loupe-aided procedure. A dual-opposing head microscope was used when creating the anastomoses with a microscope. The loupe magnification was ×3.5 for the anastomoses.
The recipient arteries used in the reconstruction included the external carotid artery (n = 62), the superior thyroid artery (n = 65), and the higher branch of the external carotid artery (n = 24). The recipient veins used in the reconstruction included the internal jugular vein (n = 101), the facial vein (n = 44), the external jugular vein (n = 28), and the temporal vein (n = 5). A 9-0 nylon microsuture was used with the microscopic anastomoses, and an 8-0 nylon microsuture was used with the loupes. The ring-type microanastomotic system coupling device was used to perform anastomoses on the most veins (112/178). Arterial anastomoses were either end-to-side to the external carotid artery or end-to-end to its branches. The veins underwent anastomoses either end-to-side to the internal jugular vein or end-to-end to the other previously mentioned recipient vessels. Large suction drains were placed in the neck, away from the anastomoses.
All patients were treated with aspirin postoperatively, 81 mg/d, for 2 weeks. Patients were kept well hydrated with crystalloid fluids to maintain adequate blood volume and pressure. Normally, intravenous dextran 40 or heparin sodium was not used postoperatively, but was used when revascularizations were required.
The FTTs were monitored hourly for the first 24 hours and then every 3 hours for the next 48 hours. Color, turgor, capillary refill, Doppler ultrasonographic findings, pulse palpation, and dermal bleeding to needlestick were used to clinically assess vascular patency.
Analysis was performed using 2-tailed t tests. Each variable was compared for statistical significance relative to the various outcomes and complications.
Patients' ages ranged from 7 to 87 years (average, 61 years). Of the 143 patients, 86 were male and 57 were female (Table 1); a total of 151 flaps were reconstructed. Two-tailed t tests proved that there were no statistical differences between the loupe and microscope groups when comparing age or sex (P>.10). Most patients had 1 flap; however, 2 patients had 2 flaps and 4 had 3 flaps. The reconstructions included the following donor sites: radial forearm, fibula, rectus abdominis, lateral arms, latissimus dorsi, scapula, and jejunum (Table 2).
To ensure surgical continuity across techniques, one of us (D.A.R.) created all microvascular anastomoses, whether loupes or a microscope was used, and was assisted by one surgeon (R.R.) for all microscope cases and by another surgeon (S.A.) for all loupe cases. By using the same lead surgeon for all microanastomoses, we believe we are as best as possible comparing 2 techniques: microscope vs loupe-aided vessel anastomosis.
The 143 reconstructed sites included the oral cavity or mandible (n = 87), the partial or total tongue (n = 31), the circumferential and noncircumferential pharynx (n = 16), the maxilla or orbita (n = 4), the temporal bone (n = 3), and the parotid (n = 2). Most defects (n = 127) were created because of ablative surgery for cancer. Other defects were a result of osteoradionecrosis of the mandible (n = 9) and benign diseases (n = 7).
Of the 151 reconstructions, 50 were performed in patients who underwent irradiation previously. Of the 67 flaps using loupes, 23 (34%) were inset into previously irradiated fields; 27 (32%) of the 84 flaps using a microscope were inset into preirradiated fields. No statistical differences (P>.10) were found when comparing the percentage of preirradiated cases in the loupe and microscope groups. Radiation did not seem to contribute to the overall complication rate.
When reviewing the medical records, we found incomplete documentation detailing the duration for the various stages of the operation, such as the ablative, the reconstructive, and the brachytherapy stages. Although the overall procedure time was available for each patient, there was inadequate and inconsistent recording of the starting time for the reconstruction team. We, therefore, were left with the complete surgical time for comparison. This was a less precise way of calculating the time contribution associated with the reconstruction, even though we believe empirically that loupe magnification took less time.
The average complete procedure time (ablation and reconstruction) for the microscope group was 652 minutes. The comparable average time for the loupes group was 613 minutes. This small difference was not statistically significant. The average operative times were also calculated for each donor site (Table 2). There were no statistical differences in the length of procedure when comparing loupes with microscope in the radial forearm or fibula reconstruction groups—the 2 largest reconstruction groups (P>.05). Even when combining these 2 groups, no demonstrable statistical differences were found in length of procedure between the loupe and the microscope groups.
The average hospitalization time for the microscope group was 21.9 days vs 24.8 days for the loupe group (P>.10). As with the operative times, the length of hospitalization was calculated for each donor site (Table 2). None of the individual donor groups had statistical differences for LOS.
Complications were divided into the following categories: venous thrombosis (n = 7), arterial thrombosis (n = 2), hematoma (n = 6), fistula (n = 3), wound dehiscence (n = 5), and partial necrosis (n = 2).
Of the 7 venous thromboses, 3 were from the loupe group and 4 from the microscope group. Three patients underwent successful salvage procedures, which included thrombectomy, use of urokinase intraoperatively, and use of intravenous heparin postoperatively for 5 days. Four flaps failed: 2 from the loupe group and 2 from the microscope group.
The 2 arterial thromboses were both from the loupe group, and both were successfully salvaged with the same techniques used for venous salvage. The reexploration rate in the loupe group was 7% (n = 5), and in the microscope group, 5% (n = 4). The overall flap survival rate was 97.0% for the loupe group and 97.6% for the microscope group. The difference between the 2 groups was not statistically significant (P>.10).
The remainder of the complications were also encountered equally between the loupe and the microscope groups.
Free tissue transfers for head and neck reconstructions have grown in popularity during the past 20 years. The enthusiasm concerning this method of reconstruction is attributed to advances in techniques and instrumentation and to more reliable donor sites.8 Discovering new ways to speed up and streamline the actual surgery and the postoperative care of patients undergoing FTT is critical not only because of the severe cost pressures to the practice of medicine but also because less anesthesia time can accelerate a patient's recovery process.
We were unable to demonstrate that loupe magnification was a more time-conserving method of creating anastomoses than the surgical microscope. While we still believe that there are actual time savings when loupes are used, our inability to obtain the actual operative time of reconstruction prevented statistical substantiation of this belief. Others9 have proved that loupe magnification can decrease operative time when creating tubal anastomoses by as much as 14%.
The rates of complications are statistically the same in both groups. There were no demonstrable increases of anastomotic failures in either. A 97.6% microscope and a 97.0% loupe success rate are highly compatible with previously published success rates for either loupe or microscopic magnification (Table 3).6,10- 16
In addition, even though our LOS data seem to be on the high end of published data for FTT, there were no differences between the microscope and the loupe groups. Miller et al17 showed that the LOS was higher in FTT patients undergoing aerodigestive tract reconstructions (21 days) compared with those undergoing non–aerodigestive tract reconstructions (16 days) of the head and neck. Our mean results of 22 and 25 days for the microscope and the loupe groups, respectively, are similar to those of Miller and coauthors, especially with 2 spurious but high LOSs (70 days in the loupe group and 30 days in the microscope group).
As standard practice, we use sterile handles for the microscope rather than draping the microscope with a sterile field. This limited area of sterility has proved tricky sometimes; on occasion, we contaminate ourselves, requiring regowning and a delay in the surgery. The convenience of being able to change the field of view by moving one's own head rather than moving a microscope cannot be overemphasized. Ready access to awkward anatomical sites can decrease a surgeon's stress level and increase effectiveness during the surgery.
Microscopes also require that the assistant and the surgeon be looking from similar angles. Loupes allow each operator to rapidly and simply be looking at the surgical fields from 2 different vantage points.
Others have challenged loupes because of operator discomfort, limitations in the visual field, and limited magnifying power. Using loupes for an extended period may predispose the operator to neck fatigue and discomfort; however, we found that by not being restricted to looking through a microscope, a shifting of the head and viewing the surgical field from a different vantage point decrease fatigue. Also, loupes are being made with lighter materials to address this complaint. Focal lengths are being improved, and the width and depth of visual fields have been improved with the wide-angle view loupes. The power of magnification has never been an issue in our practice, and we use ×3.5 magnification without difficulty. Although magnification of up to ×6.5 is readily available, we have not seen the need for loupes of that power.
We advocate loupe magnification because of its reasonable cost, the surgeon's comfort, portability, and, most likely, efficiency. Two pairs of loupes (one for the surgeon and the other for the assistant) cost far less than a surgical microscope. Loupes require little maintenance, whereas a surgical microscope must be serviced often—especially in busy operating rooms. Nurses do not have to be trained on how to maintain loupes, whereas extensive training is required of any health care professional in the use and maintenance of the microscope. In some communities, the high cost of a surgical microscope makes loupes an affordable and far less expensive alternative in the capital budget of the operating room. In many countries, the cost of the operating microscope and its maintenance are prohibitive; the operating loupes allow for the use of free flaps in virtually any operating room setting, permanent and temporary. Our article reports the safety and efficacy of this approach.
Because of the favorable results we achieved when using loupes for microanastomoses, we have all but abandoned the operating microscope when performing such reconstructions. Although we have not yet seen a case in which the microscope would be useful, there may be instances in which the microscope may be necessary, particularly when the vessel's diameter (<1-mm lumen) is not well seen.
In conclusion, to our knowledge, we report the largest number of head and neck reconstruction cases comparing loupe with microscope magnification for the creation of microanastomoses. Loupes offer the surgeon comfort and easy access to and uncomplicated visualization of the operating field. Furthermore, loupes may decrease operating time and avoid complicated equipment. We conclude that loupe magnification should be considered in the armamentarium of head and neck reconstruction without the fear of increased morbidity.
Corresponding author and reprints: Douglas A. Ross, MD, Section of Otolaryngology, Yale University School of Medicine, 333 Cedar St, Campus Box 208041, New Haven, CT 06520-8041.
Accepted for publication July 3, 2002.
This study was supported in part by the McFadden, Harmon, and Mirikitani Endowments, all located in New Haven.
This study was presented at the 104th Annual Meeting of the American Laryngological, Rhinological, and Otological Society Inc, Palm Desert, Calif, May 15, 2001.
We thank Ann M. Ross, MD, and Jan Sucher, MD, for their invaluable help in preparing the manuscript.