| Changes in carrying amount of goodwill |
The changes in the carrying amount of goodwill for the years ended December 31, 2024 and 2023, are as follows (in thousands): | | | | | | | | | | | | | | | | | | | | | 2024 | | 2023 | | | Cardiovascular | | Endoscopy | | Total | | Cardiovascular | | Endoscopy | | Total | Goodwill balance at January 1 | | $ | 382,240 | | $ | — | | $ | 382,240 | | $ | 359,821 | | $ | — | | $ | 359,821 | Effect of foreign exchange | | | (1,623) | | | — | | | (1,623) | | | 883 | | | — | | | 883 | Additions and adjustments as the result of acquisitions | | | 65,897 | | | 16,997 | | | 82,894 | | | 21,536 | | | — | | | 21,536 | Goodwill balance at December 31 | | $ | 446,514 | | $ | 16,997 | | $ | 463,511 | | $ | 382,240 | | $ | — | | $ | 382,240 |
|
| Other intangible assets |
Other intangible assets at December 31, 2024 and 2023, consisted of the following (in thousands): | | | | | | | | | | | | December 31, 2024 | | | Gross Carrying | | Accumulated | | Net Carrying | | | Amount | | Amortization | | Amount | Patents | | $ | 31,489 | | $ | (12,824) | | $ | 18,665 | Distribution agreements | | | 3,250 | | | (2,994) | | | 256 | License agreements | | | 11,557 | | | (9,125) | | | 2,432 | Trademarks | | | 47,613 | | | (24,177) | | | 23,436 | Customer lists | | | 57,933 | | | (36,223) | | | 21,710 | Total | | $ | 151,842 | | $ | (85,343) | | $ | 66,499 |
| | | | | | | | | | | | December 31, 2023 | | | Gross Carrying | | Accumulated | | Net Carrying | | | Amount | | Amortization | | Amount | Patents | | $ | 28,877 | | $ | (10,916) | | $ | 17,961 | Distribution agreements | | | 3,250 | | | (2,919) | | | 331 | License agreements | | | 11,142 | | | (8,327) | | | 2,815 | Trademarks | | | 35,135 | | | (20,804) | | | 14,331 | Customer lists | | | 40,367 | | | (33,921) | | | 6,446 | Total | | $ | 118,771 | | $ | (76,887) | | $ | 41,884 |
|
| Estimated amortization expense |
Estimated amortization expense for the developed technology and other intangible assets for the next five years consists of the following as of December 31, 2024 (in thousands): | | | | Year ending December 31, | | Estimated Amortization Expense | 2025 | | $ | 83,747 | 2026 | | | 73,155 | 2027 | | | 69,188 | 2028 | | | 67,790 | 2029 | | | 56,115 |
|