Microwave therapy zaps hyperhidrosis long-term

MAUI, HAWAII – The future of hyperhidrosis therapy may be microwave ablation, a Food and Drug Administration–cleared method of destroying sweat glands noninvasively.

"We’ve seen that it’s effective in about 90% of patients, the patients are really satisfied, and the side effects are transient," Dr. Nazanin Saedi said at the Hawaii Dermatology Seminar, sponsored by Global Academy for Medical Education/Skin Disease Education Foundation.

Larger patient numbers and more long-term data are needed before the therapy becomes common in clinical practice, but it shouldn’t take long to accumulate such data, because the proprietary miraDry microwave treatment system (marketed by Miramar Labs) is much in demand by patients, noted Dr. Saedi of Thomas Jefferson University, Philadelphia.

An estimated 4.3 million Americans have axillary hyperhidrosis, Dr. Saedi said. Numerous treatment options are available, but most have significant drawbacks, she noted. First-line therapy is topical aluminum chloride, with or without salicylic acid; irritant dermatitis is a common complaint.

Second-line options include iontophoresis, which requires treatments two or three times per week and can be quite painful, Dr. Saedi said. Botulinum toxin A injections are highly effective, but they must be repeated every 4-6 months, and can cause weakness of the underlying muscles. Oral medications include anticholinergic agents and alpha₂-adrenergic drugs, all with side effects many patients find problematic.

Before microwave therapy, surgical procedures were the only means of destroying sweat glands, and surgery is considered third-line therapy, Dr. Saedi said.

"Now that we have the newer technologies, I think surgery will become even more rare," she predicted.

The study that earned the miraDry device its Food and Drug Administration marketing clearance was a blinded trial in which 120 patients were randomized 2:1 to microwave therapy or a sham procedure. At baseline, all participants were rated 3 or 4 on the 1-4 Hyperhidrosis Disease Severity Scale (HDSS). At a follow-up point of 30 days, 89% of patients in the treatment group met the primary endpoint – an HDSS score of 1 or 2 – compared with 54% of controls. Roughly 70% of patients in the microwave treatment group still had an HDSS score of 1-2 at 12 months (Dermatol. Surg. 2012;38:185-91).

However, that study involved an earlier-generation, less efficient device, Dr. Saedi noted. In an open-label study of 31 patients treated with the current-generation, commercially available miraDry device, all subjects had a baseline HDSS score of 3 or 4. Twelve months after patients received 1-3 treatment sessions, 90% had an HDSS score of 1 or 2. In addition, 90% of patients had at least a 50% reduction in gravimetrically measured axillary sweat, and 85% had at least a 5-point improvement on the Dermatologic Life Quality Index (Dermatol. Surg. 2012;38:728-35).

In the microwave treatment procedure, an applicator is placed on the skin surface to deliver focused energy to the dermal-fat interface, where sweat glands are located. Microwaves are preferentially absorbed by tissues with high water content, such as sweat glands, and poorly absorbed by fat. A cooling system keeps the heat at the lower skin layer. A heat dome at about 60° C is created along the dermal-fat junction, resulting in sweat gland thermolysis, Dr. Saedi explained.

Two hours prior to treatment, the patient takes 800 mg of ibuprofen. A grid of temporary markings is placed over the area to be treated, and the dermis is anesthetized with injections of a 1:1 mix of 1% plain lidocaine and 1% lidocaine plus epinephrine at 1-cm intervals.

Microwave therapy entails two treatment sessions roughly 3 months apart. The first typically takes 60-90 minutes, the second 30-60 minutes.

Dr. Saedi said swelling, bruising, discomfort, and altered sensation in and around the treatment area are all common side effects of microwave therapy, but all are short-term. Less common side effects include swelling extending beyond the treatment area, a tight banding sensation in the axilla, and arm and hand numbness lasting less than 24 hours, she said.

One audience member who has treated 130 patients via microwave therapy reported that one of them developed a significant brachial nerve palsy that has lasted for 5 months. As a consequence, the commenter said he now routinely employs tumescent anesthesia in an effort to steer clear of the axillary nerve bundles. But Dr. Suzanne L. Kilmer said she doubts that will prevent the occasional case of brachial nerve palsy, which she believes is the result of variant anatomy.

"We’ve done the procedure on many thin people, and not had brachial nerve palsy be an issue, so I’m not sure that tumescent anesthesia will make a difference," said Dr. Kilmer of the University of California, Davis.

Pulsed ultrasound is currently under investigation as a means of treating hyperhidrosis through destruction of sweat glands, session moderator Dr. Christopher B. Zachary said in response to an audience question. "This would be an off-label indication right now, but you can absolutely hit that region with an ultrasound device and cause heating. It’s quite likely that ultrasound will be used extensively in exactly the same way as microwave, and probably with the same efficacy," predicted Dr. Zachary of the University of California, Irvine.

Dr. Zachary is a consultant to and has received research funding from numerous laser and other medical device companies, as has Dr. Kilmer. Dr. Saedi had no financial conflicts to disclose. SDEF and this news organization are owned by the same parent company.

bjancin@frontlinemedcom.com

MAUI, HAWAII – The future of hyperhidrosis therapy may be microwave ablation, a Food and Drug Administration–cleared method of destroying sweat glands noninvasively.

"We’ve seen that it’s effective in about 90% of patients, the patients are really satisfied, and the side effects are transient," Dr. Nazanin Saedi said at the Hawaii Dermatology Seminar, sponsored by Global Academy for Medical Education/Skin Disease Education Foundation.

Larger patient numbers and more long-term data are needed before the therapy becomes common in clinical practice, but it shouldn’t take long to accumulate such data, because the proprietary miraDry microwave treatment system (marketed by Miramar Labs) is much in demand by patients, noted Dr. Saedi of Thomas Jefferson University, Philadelphia.

An estimated 4.3 million Americans have axillary hyperhidrosis, Dr. Saedi said. Numerous treatment options are available, but most have significant drawbacks, she noted. First-line therapy is topical aluminum chloride, with or without salicylic acid; irritant dermatitis is a common complaint.

Second-line options include iontophoresis, which requires treatments two or three times per week and can be quite painful, Dr. Saedi said. Botulinum toxin A injections are highly effective, but they must be repeated every 4-6 months, and can cause weakness of the underlying muscles. Oral medications include anticholinergic agents and alpha₂-adrenergic drugs, all with side effects many patients find problematic.

Before microwave therapy, surgical procedures were the only means of destroying sweat glands, and surgery is considered third-line therapy, Dr. Saedi said.

"Now that we have the newer technologies, I think surgery will become even more rare," she predicted.

The study that earned the miraDry device its Food and Drug Administration marketing clearance was a blinded trial in which 120 patients were randomized 2:1 to microwave therapy or a sham procedure. At baseline, all participants were rated 3 or 4 on the 1-4 Hyperhidrosis Disease Severity Scale (HDSS). At a follow-up point of 30 days, 89% of patients in the treatment group met the primary endpoint – an HDSS score of 1 or 2 – compared with 54% of controls. Roughly 70% of patients in the microwave treatment group still had an HDSS score of 1-2 at 12 months (Dermatol. Surg. 2012;38:185-91).

However, that study involved an earlier-generation, less efficient device, Dr. Saedi noted. In an open-label study of 31 patients treated with the current-generation, commercially available miraDry device, all subjects had a baseline HDSS score of 3 or 4. Twelve months after patients received 1-3 treatment sessions, 90% had an HDSS score of 1 or 2. In addition, 90% of patients had at least a 50% reduction in gravimetrically measured axillary sweat, and 85% had at least a 5-point improvement on the Dermatologic Life Quality Index (Dermatol. Surg. 2012;38:728-35).

In the microwave treatment procedure, an applicator is placed on the skin surface to deliver focused energy to the dermal-fat interface, where sweat glands are located. Microwaves are preferentially absorbed by tissues with high water content, such as sweat glands, and poorly absorbed by fat. A cooling system keeps the heat at the lower skin layer. A heat dome at about 60° C is created along the dermal-fat junction, resulting in sweat gland thermolysis, Dr. Saedi explained.

Two hours prior to treatment, the patient takes 800 mg of ibuprofen. A grid of temporary markings is placed over the area to be treated, and the dermis is anesthetized with injections of a 1:1 mix of 1% plain lidocaine and 1% lidocaine plus epinephrine at 1-cm intervals.

Microwave therapy entails two treatment sessions roughly 3 months apart. The first typically takes 60-90 minutes, the second 30-60 minutes.

Dr. Saedi said swelling, bruising, discomfort, and altered sensation in and around the treatment area are all common side effects of microwave therapy, but all are short-term. Less common side effects include swelling extending beyond the treatment area, a tight banding sensation in the axilla, and arm and hand numbness lasting less than 24 hours, she said.

One audience member who has treated 130 patients via microwave therapy reported that one of them developed a significant brachial nerve palsy that has lasted for 5 months. As a consequence, the commenter said he now routinely employs tumescent anesthesia in an effort to steer clear of the axillary nerve bundles. But Dr. Suzanne L. Kilmer said she doubts that will prevent the occasional case of brachial nerve palsy, which she believes is the result of variant anatomy.

"We’ve done the procedure on many thin people, and not had brachial nerve palsy be an issue, so I’m not sure that tumescent anesthesia will make a difference," said Dr. Kilmer of the University of California, Davis.

Pulsed ultrasound is currently under investigation as a means of treating hyperhidrosis through destruction of sweat glands, session moderator Dr. Christopher B. Zachary said in response to an audience question. "This would be an off-label indication right now, but you can absolutely hit that region with an ultrasound device and cause heating. It’s quite likely that ultrasound will be used extensively in exactly the same way as microwave, and probably with the same efficacy," predicted Dr. Zachary of the University of California, Irvine.

Dr. Zachary is a consultant to and has received research funding from numerous laser and other medical device companies, as has Dr. Kilmer. Dr. Saedi had no financial conflicts to disclose. SDEF and this news organization are owned by the same parent company.

bjancin@frontlinemedcom.com

MAUI, HAWAII – The future of hyperhidrosis therapy may be microwave ablation, a Food and Drug Administration–cleared method of destroying sweat glands noninvasively.

"We’ve seen that it’s effective in about 90% of patients, the patients are really satisfied, and the side effects are transient," Dr. Nazanin Saedi said at the Hawaii Dermatology Seminar, sponsored by Global Academy for Medical Education/Skin Disease Education Foundation.

Larger patient numbers and more long-term data are needed before the therapy becomes common in clinical practice, but it shouldn’t take long to accumulate such data, because the proprietary miraDry microwave treatment system (marketed by Miramar Labs) is much in demand by patients, noted Dr. Saedi of Thomas Jefferson University, Philadelphia.

An estimated 4.3 million Americans have axillary hyperhidrosis, Dr. Saedi said. Numerous treatment options are available, but most have significant drawbacks, she noted. First-line therapy is topical aluminum chloride, with or without salicylic acid; irritant dermatitis is a common complaint.

Second-line options include iontophoresis, which requires treatments two or three times per week and can be quite painful, Dr. Saedi said. Botulinum toxin A injections are highly effective, but they must be repeated every 4-6 months, and can cause weakness of the underlying muscles. Oral medications include anticholinergic agents and alpha₂-adrenergic drugs, all with side effects many patients find problematic.

Before microwave therapy, surgical procedures were the only means of destroying sweat glands, and surgery is considered third-line therapy, Dr. Saedi said.

"Now that we have the newer technologies, I think surgery will become even more rare," she predicted.

The study that earned the miraDry device its Food and Drug Administration marketing clearance was a blinded trial in which 120 patients were randomized 2:1 to microwave therapy or a sham procedure. At baseline, all participants were rated 3 or 4 on the 1-4 Hyperhidrosis Disease Severity Scale (HDSS). At a follow-up point of 30 days, 89% of patients in the treatment group met the primary endpoint – an HDSS score of 1 or 2 – compared with 54% of controls. Roughly 70% of patients in the microwave treatment group still had an HDSS score of 1-2 at 12 months (Dermatol. Surg. 2012;38:185-91).

However, that study involved an earlier-generation, less efficient device, Dr. Saedi noted. In an open-label study of 31 patients treated with the current-generation, commercially available miraDry device, all subjects had a baseline HDSS score of 3 or 4. Twelve months after patients received 1-3 treatment sessions, 90% had an HDSS score of 1 or 2. In addition, 90% of patients had at least a 50% reduction in gravimetrically measured axillary sweat, and 85% had at least a 5-point improvement on the Dermatologic Life Quality Index (Dermatol. Surg. 2012;38:728-35).

In the microwave treatment procedure, an applicator is placed on the skin surface to deliver focused energy to the dermal-fat interface, where sweat glands are located. Microwaves are preferentially absorbed by tissues with high water content, such as sweat glands, and poorly absorbed by fat. A cooling system keeps the heat at the lower skin layer. A heat dome at about 60° C is created along the dermal-fat junction, resulting in sweat gland thermolysis, Dr. Saedi explained.

Two hours prior to treatment, the patient takes 800 mg of ibuprofen. A grid of temporary markings is placed over the area to be treated, and the dermis is anesthetized with injections of a 1:1 mix of 1% plain lidocaine and 1% lidocaine plus epinephrine at 1-cm intervals.

Microwave therapy entails two treatment sessions roughly 3 months apart. The first typically takes 60-90 minutes, the second 30-60 minutes.

Dr. Saedi said swelling, bruising, discomfort, and altered sensation in and around the treatment area are all common side effects of microwave therapy, but all are short-term. Less common side effects include swelling extending beyond the treatment area, a tight banding sensation in the axilla, and arm and hand numbness lasting less than 24 hours, she said.

One audience member who has treated 130 patients via microwave therapy reported that one of them developed a significant brachial nerve palsy that has lasted for 5 months. As a consequence, the commenter said he now routinely employs tumescent anesthesia in an effort to steer clear of the axillary nerve bundles. But Dr. Suzanne L. Kilmer said she doubts that will prevent the occasional case of brachial nerve palsy, which she believes is the result of variant anatomy.

"We’ve done the procedure on many thin people, and not had brachial nerve palsy be an issue, so I’m not sure that tumescent anesthesia will make a difference," said Dr. Kilmer of the University of California, Davis.

Pulsed ultrasound is currently under investigation as a means of treating hyperhidrosis through destruction of sweat glands, session moderator Dr. Christopher B. Zachary said in response to an audience question. "This would be an off-label indication right now, but you can absolutely hit that region with an ultrasound device and cause heating. It’s quite likely that ultrasound will be used extensively in exactly the same way as microwave, and probably with the same efficacy," predicted Dr. Zachary of the University of California, Irvine.

Dr. Zachary is a consultant to and has received research funding from numerous laser and other medical device companies, as has Dr. Kilmer. Dr. Saedi had no financial conflicts to disclose. SDEF and this news organization are owned by the same parent company.

bjancin@frontlinemedcom.com